CN118219177A - Electric tool and method for acquiring phase information of alternating current signal - Google Patents
Electric tool and method for acquiring phase information of alternating current signal Download PDFInfo
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- CN118219177A CN118219177A CN202211571516.2A CN202211571516A CN118219177A CN 118219177 A CN118219177 A CN 118219177A CN 202211571516 A CN202211571516 A CN 202211571516A CN 118219177 A CN118219177 A CN 118219177A
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- 238000000034 method Methods 0.000 title claims abstract description 22
- 238000012545 processing Methods 0.000 claims abstract description 50
- 238000004146 energy storage Methods 0.000 claims description 8
- 238000001914 filtration Methods 0.000 claims description 3
- 230000017525 heat dissipation Effects 0.000 claims description 3
- 238000006243 chemical reaction Methods 0.000 claims description 2
- 238000010586 diagram Methods 0.000 description 19
- 230000010363 phase shift Effects 0.000 description 8
- 238000012546 transfer Methods 0.000 description 5
- 238000011217 control strategy Methods 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 2
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
- B24B51/00—Arrangements for automatic control of a series of individual steps in grinding a workpiece
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
- B24B23/00—Portable grinding machines, e.g. hand-guided; Accessories therefor
- B24B23/02—Portable grinding machines, e.g. hand-guided; Accessories therefor with rotating grinding tools; Accessories therefor
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/44—Circuits or arrangements for compensating for electromagnetic interference in converters or inverters
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P6/00—Arrangements for controlling synchronous motors or other dynamo-electric motors using electronic commutation dependent on the rotor position; Electronic commutators therefor
- H02P6/14—Electronic commutators
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Mechanical Engineering (AREA)
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Control Of Ac Motors In General (AREA)
Abstract
The application discloses an electric tool and a method for acquiring phase information of an alternating current signal, wherein the electric tool comprises the following components: a housing; the power supply input device is used for connecting an alternating current signal so as to provide electric energy required by the electric tool during operation; a motor; a drive circuit electrically connected to the motor; the driving circuit is used for driving the motor; the controller is electrically connected with the driving circuit and is used for outputting a control signal to the driving circuit so as to control the motor to run; the signal processing device comprises a phase shifting module; the phase shifting module is used for converting the alternating current electric signal into a first electric signal and a second electric signal; the first electrical signal and the second electrical signal have the same amplitude and differ in phase angle by 90 degrees; the signal processing device is also used for acquiring phase information of the alternating current signal accessed by the power input device according to the first electric signal and the second electric signal; the controller is configured to regulate the control signal based on the phase information. The scheme provided by the application can accurately acquire the phase information of the alternating current signal.
Description
Technical Field
The present application relates to the field of power electronics, and more particularly, to an electric tool and a method for acquiring phase information of an ac signal.
Background
During the running process of an alternating current tool (such as a high-voltage brushless angle grinder), input and output are required to be detected so as to perform closed-loop negative feedback control, but an input signal often has interference and distortion so as to influence a control strategy, and therefore, information such as phase, frequency and the like of the input signal needs to be accurately acquired. In the related art, the waveform of an input signal is determined by detecting a zero crossing point, and under overlong wire harnesses or other environmental interference, sine wave burrs are larger, and particularly if frequent oscillation occurs near the zero crossing point, detection deviation is larger easily caused.
Disclosure of Invention
The embodiment of the application provides an electric tool and a method for acquiring phase information of an alternating current signal, which can accurately acquire the phase information of an input signal when the input signal of the electric tool is unstable.
In a first aspect, an embodiment of the present application provides a power tool including:
A housing;
The power supply input device is used for being connected with an alternating current signal so as to provide electric energy required by the electric tool during operation;
A motor;
a drive circuit electrically connected to the motor; the driving circuit is used for driving the motor;
The controller is electrically connected with the driving circuit and is used for outputting a control signal to the driving circuit so as to control the motor to run;
the signal processing device comprises a phase shifting module; the phase shifting module is used for converting the alternating current signal into a first electric signal and a second electric signal; the first electrical signal and the second electrical signal have the same amplitude and differ in phase angle by 90 degrees; the signal processing device is further used for acquiring phase information of the alternating current signal accessed by the power input device according to the first electric signal and the second electric signal;
The controller is configured to regulate the control signal based on the phase information.
In a second aspect, an embodiment of the present application provides a method for acquiring phase information of an ac electrical signal, where the ac electrical signal is used to provide electrical energy for an electric tool or an energy storage device, the method including:
Processing the alternating current electric signal through a phase shifting module to obtain a first electric signal and a second electric signal;
Processing the first electric signal and the second electric signal through a phase-locked loop module to acquire phase information of the alternating current signal; wherein the first electrical signal and the second electrical signal have the same amplitude and differ in phase angle by 90 °.
In the application, the signal processing device is arranged in the electric tool, when the power input device of the electric tool is connected with the working power supply of the alternating current electric signal so as to control the driving circuit to drive the motor to drive the electric tool to work, the signal processing device can carry out phase shifting processing on the alternating current electric signal to obtain a first electric signal and a second electric signal, and obtain accurate phase information of the alternating current electric signal according to the first electric signal and the second electric signal, so that the controller controls the operation of the motor based on the phase information. Even if the AC electric signal accessed by the electric tool is unstable due to interference and distortion output voltage, the electric tool in the embodiment of the application can accurately acquire the phase information of the input signal, and the influence of the interference and the distortion on the control strategy of the working state of the electric tool is avoided.
Drawings
Fig. 1 is a schematic structural diagram of an electric tool according to an embodiment of the present application;
Fig. 2 is a control block diagram of a signal processing apparatus according to an embodiment of the present application;
FIG. 3 is a bird diagram of the transfer function according to an embodiment of the present application;
fig. 4 is a schematic structural diagram of a signal processing device according to an embodiment of the present application;
Fig. 5 is a control block diagram of another signal processing apparatus according to an embodiment of the present application;
FIG. 6 is a B-chart of transfer functions corresponding to the control block diagram of FIG. 5;
Fig. 7 is a control block diagram of another signal processing apparatus according to an embodiment of the present application;
FIG. 8 is a schematic diagram of another electric tool according to an embodiment of the present application;
fig. 9 is a flowchart of a method for acquiring phase information of an ac signal according to an embodiment of the present application.
Detailed Description
The application is described in further detail below with reference to the drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the application and are not limiting thereof. It should be further noted that, for convenience of description, only some, but not all of the structures related to the present application are shown in the drawings.
Those of ordinary skill in the art will understand that relative terms (e.g., "about," "approximately," "generally," "substantially," etc.) used in connection with a quantity or condition are intended to encompass the stated value and have the meaning dictated by the context (e.g., the term includes at least the degree of error associated with measurement of the particular value, tolerances (e.g., manufacturing, assembly, use) associated with the particular value, etc.). Such terms should also be considered to disclose a range defined by the absolute values of the two endpoints. Relative terms may refer to a percentage (e.g., 1%,5%,10% or more) of the indicated value plus or minus. Of course, numerical values that do not take relative terms should also be construed as having particular values within tolerances.
As described above, in the operation of the ac power tool, it is necessary to accurately acquire information such as the phase and frequency of the input signal to perform negative feedback control of the input or output, thereby performing control of the motor in the ac power tool. In addition, when the motor is operated, the position and the rotation speed of the rotor need to be accurately detected, and the rotation speed and the relative position of the motor can be determined by detecting the frequency and the phase of the counter potential waveforms of the three phases formed on the stator by the rotor. That is, the phase information of the input signal can be accurately acquired, which is critical to the operation of the ac tool.
Fig. 1 is a schematic structural diagram of an electric tool according to an embodiment of the present application, the electric tool includes: a housing 11;
A power input device 12 for switching in an ac signal to supply electric power required by the electric tool when in operation;
A motor 13;
A drive circuit 14 electrically connected to the motor 13; the driving circuit 14 is used for driving the motor;
A controller 16 electrically connected to the driving circuit 14 for outputting a control signal to the driving circuit 14 to control the motor 13;
A signal processing device 15 including a phase shift module 151; the phase shifting module 151 is configured to convert an ac electrical signal into a first electrical signal and a second electrical signal; the first voltage signal and the second electrical signal have the same magnitude and differ in phase angle by 90 °. Specifically, the first electrical signal has the same amplitude as the alternating current electrical signal and the same phase angle. The second electrical signal is the same magnitude as the first electrical signal, and the phase angles differ by 90 °. The signal processing device 15 is further configured to obtain phase information of the ac signal accessed by the power input device 12 according to the first electrical signal and the second electrical signal output by the phase shifting module 151; the controller 16 is configured to regulate the control signal based on the acquired phase information.
In the embodiment of the application, the signal processing device is arranged in the electric tool, when the power input device of the electric tool is connected with the working power supply of the alternating current signal so as to control the driving circuit to drive the motor to drive the electric tool to work, the signal processing device can perform phase shifting processing on the alternating current signal to obtain the first electric signal and the second electric signal, and obtain accurate phase information of the alternating current signal according to the first electric signal and the second electric signal, so that the controller controls the operation of the motor based on the phase information. Even if the AC electric signal accessed by the electric tool is unstable due to interference and distortion output voltage, the electric tool in the embodiment of the application can accurately acquire the phase information of the input signal, and the influence of the interference and the distortion on the control strategy of the working state of the electric tool is avoided.
The foregoing is the core idea of the present application, and the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without making any inventive effort are intended to fall within the scope of the present application.
A power tool is a device in which a motor moves a part to perform a certain work, such as a cutter, an angle grinder, etc. In this embodiment, the electric tool is typically a high-voltage electric tool, and is connected to an ac voltage of 220V or more to control the motor to perform high-intensity motion. The high-voltage electric tool is widely applied to processing of materials such as metal, food materials, wood, ceramics and the like, and the industrialization process is accelerated.
The electric tool in this embodiment includes a housing 11, and a power input device 12, a driving circuit 14, a motor 13, a signal processing device 15, and a controller 16 that are located inside the housing 11. Wherein the housing 11 is used for protecting a plurality of components therein from external interference. The power input device 12 is used for connecting to a working power source required by the operation of the electric tool, and the working power source in this embodiment is an ac electric signal, and is one phase of three-phase ac mains supply, for example, may be one phase of 120V or 220V ac mains supply. The driving circuit 14 can drive the motor 13 to rotate, and the rotating motor 13 can drive the movable part to move, so that various operations of the electric tool are completed. It should be noted that the electric tool in this embodiment includes a signal processing device 15, where the signal processing device 15 is electrically connected to the power input device 12, and is configured to obtain phase information of the ac electric signal from which interference and fluctuation are removed according to the ac electric signal input by the power input device 12. Specifically, the signal processing device 15 may include a phase shifting module 151, where the phase shifting module 151 is capable of converting an alternating current signal into a first electrical signal and a second electrical signal having an orthogonal relationship. The amplitude of the first electric signal is the same as that of the alternating current electric signal, and the phase angle is the same; the second electrical signal is the same amplitude as the alternating current signal, and the phase angle lags by 90 °.
In some embodiments, with continued reference to fig. 1, the signal processing apparatus 15 further includes a phase-locked loop module 153; the phase-locked loop module 153 is configured to access the first electrical signal and the second electrical signal output by the phase shifting module 151, and output phase information of the ac electrical signal. The phase shift module 151 outputs the first and second electrical signals to the phase-locked loop module 153, and the phase-locked loop module 153 processes the input first and second electrical signals to output phase information of the alternating current electrical signal. In some embodiments, the phase-locked loop module 153 includes, but is not limited to, a quadrature phase-locked loop or DQ conversion module, which is not particularly limited in this embodiment.
In some embodiments, the controller 16 is configured to control operation of the motor based on the phase information of the acquired alternating current signal. Specifically, the motor is a brushless motor. The control signal output by the controller is a PWM signal. The controller is configured to reduce a duty ratio of the PWM signal when a phase of the alternating current signal is 90 ° or 270 °, thereby controlling a current flowing through the driving circuit.
In some embodiments, the method for obtaining the phase information of the ac signal may also be applied in the technical field of charging the energy storage device. Specifically, the energy storage device is a battery pack. The battery pack is connected to the commercial power, i.e., the alternating current signal, through a charger for charging. When the alternating current signal is electrically connected to the charger to charge the battery pack, the power factor correction can be performed on the charging system by acquiring the phase information of the alternating current signal, so that the charging efficiency is improved, and meanwhile, the charging reliability is improved.
In some embodiments, the method for acquiring the phase information of the ac signal may also be applied to the case of back charging the power grid. In particular, the energy storage device is in some cases capable of feeding back the electrical energy stored inside it to the electrical grid. . When the energy storage device feeds the power grid, whether the active power or the reactive power transmitted on the current power grid is required to be judged. Those skilled in the art will appreciate that during the transmission of electricity from the grid to a consumer, there are two types of power percentages that the grid is to provide to the load: active power and reactive power. Active power refers to the electrical power required to maintain the operation of the device, i.e., the degree of electrical power that converts electrical energy into other forms of energy (mechanical energy, optical energy, thermal energy, etc.). Reactive power refers to the electric power required by the elements such as inductance, capacitance and the like in the electrical equipment to establish a magnetic field when in operation. In fact, when the energy storage device is configured to feed the power grid, it is necessary to determine whether the active power and the reactive power are currently transmitted by the power grid, and to feed the power grid when the active power is currently transmitted by the power grid. In fact, after the phase information of the ac signal output by the power grid is obtained, the current state of the power grid can be determined. I.e. whether active or reactive power is currently being transmitted. Thus, the method for acquiring the phase information of the alternating current signal based on the phase information of the power grid acquires the phase information of the power grid, so that the operation of feeding the power grid is controlled, and the waste of energy sources can be avoided. .
As shown in fig. 2, fig. 2 is a control block diagram of a signal processing apparatus according to an embodiment of the present application. In some embodiments, the collected voltage and current variables are reconstructed using a second-order generalized integrator whose input is a phase input voltage signal v, which is typically a noisy sine wave signal, and 2 orthogonal relatively noiseless first and second electrical signals v 'and qv' are output by a phase shift module 151. The transfer function between the two output and input amounts is:
Where k is the attenuation coefficient and ω 0 is the resonant angular frequency.
With continued reference to fig. 2, in some embodiments, the phase shifting module 151 may include a bandpass filter and a first low pass filter; the phase shifting module 151 is specifically configured to filter the ac electrical signal v to obtain a first electrical signal v' by filtering the high-frequency interference signal and the low-frequency interference signal with a band-pass filter; the phase shifting module 151 is specifically further configured to filter the high-frequency interference signal from the alternating current signal v through a first low-pass filter, and obtain a second electrical signal qv'. That is, the phase shift module 151 itself carries a band pass filter and a first low pass filter. The alternating current electric signal v passes through a band-pass filter to remove a high-frequency interference signal and a low-frequency interference signal, and a first electric signal v' with unchanged amplitude and phase is obtained. The alternating current signal v passes through a low-pass filter to filter out high-frequency interference signals, and a second electric signal qv' with the unchanged amplitude and the phase angle of 90 degrees is obtained.
Referring to fig. 1 and 2, an embodiment of the present application can convert an ac signal v with noise into 2 orthogonal first and second electrical signals v 'and qv' with relatively no noise through a phase shift module 151 for subsequent phase information acquisition.
Fig. 3 is a bode diagram of the transfer function according to an embodiment of the present application. The abscissas of the bode diagrams H d(s) and H q(s) in fig. 3 represent the frequency f, the left ordinate represents the amplitude T, and the right ordinate represents the phase angle θ. The solid line T v (f) represents the amplitude curve of the first electrical signal v ', and the dashed line θ v (f) represents the phase curve of the first electrical signal v'. Similarly, a solid line T qv (f) represents the amplitude curve of the second electric signal qv ', and a broken line θ qv (f) represents the phase curve of the second electric signal qv'. As can be seen from fig. 3, H d(s) is a bandpass filter, around 50HZ, the magnitude is unchanged, the phase angle shift is 0 degrees, while H q(s) is a lowpass filter, around 50HZ, the magnitude is unchanged, and the phase angle is 90 degrees behind. According to the design expected by us, two waveforms with unchanged assignment and mutually orthogonal values are generated.
In some embodiments, as shown in fig. 4, the signal processing device 15 further includes: a compensation module 152; the signal processing device 15 is further configured to remove the low-frequency interference signal and the dc offset signal of the second electrical signal through the compensation module 152, so as to obtain a third electrical signal; the signal processing module 15 is configured to obtain phase information of the ac electrical signal according to the first electrical signal and the third electrical signal.
In order to further remove the noise of the second electrical signal, the low frequency or dc offset voltage in the second electrical signal is removed by the compensation module 152, and the self-adaptive filter of the phase shift module 151 is a low-pass filter, so that the low frequency or dc offset part cannot be filtered, so that the embodiment can add reverse compensation after the second electrical signal, remove the influence of the low frequency or dc offset, and obtain the third electrical signal, in other words, the third electrical signal is the second electrical signal after removing the noise, which may also be referred to as an accurate second electrical signal, and the signal processing module 15 can obtain the phase information of the ac electrical signal more accurately according to the first electrical signal and the third electrical signal.
In some embodiments, as shown in fig. 2 and 4, the signal processing device 15 further includes: a feedback module 154; the feedback module 154 is configured to make a difference between the ac signal v and the first electrical signal v' and output a first difference signal epsilon to the phase shift module 151; so that the phase shifting module 151 regulates the first electrical signal v 'and the second electrical signal qv' according to the first difference signal epsilon to obtain a stable and controllable first electrical signal v 'and a second electrical signal qv', which is beneficial to obtaining more accurate phase information of the ac electrical signal.
Fig. 5 is a control block diagram of another signal processing apparatus according to an embodiment of the present application. Referring to fig. 4 and 5, in some embodiments, the compensation module 152 may include a second low pass filter LPF; the compensation module 152 is configured to filter the first difference signal epsilon by a second low-pass filter LPF, and then compensate the second electrical signal qv ' to obtain a third electrical signal qv i ', and specifically obtain the first difference signal epsilon by an alternating current signal v and the first electrical signal v '; passing the first difference signal epsilon through a low pass filter LPF to obtain a fourth voltage signal q1v' without high-frequency interference signals; the fourth voltage signal q1v ' is compensated in anti-phase to the second electrical signal qv ' to form a third electrical signal qv i '. The control block diagram shown in fig. 5 is a third electric signal qv i 'obtained by adding reverse compensation after the second electric signal qv', so that low-frequency and direct-current components are effectively removed, and the control precision of the electric tool is improved.
Fig. 6 is a bode plot of transfer functions corresponding to the control block diagram of fig. 5. The solid line T v (f) represents the amplitude curve of the first electrical signal v ', and the dashed line θ v (f) represents the phase curve of the first electrical signal v'. The solid line T qv2 (f) represents the amplitude curve of the third electrical signal qv i ', and the dashed line θ qv2 (f) represents the phase curve of the third electrical signal qv i'. It has no effect on the Bode diagram H d(s), hd(s) is a bandpass filter, the magnitude is unchanged near 50HZ, and the phase angle shift is 0 degrees. However, the bode diagram H q'(s) of the third electrical signal qv i' is different from H q(s) in fig. 3, and the effect of the band-pass filter is formed by H q'(s), so that the low frequency or direct current offset is shielded, and the control precision of the electric tool is effectively improved.
Fig. 7 is a control block diagram of another signal processing apparatus according to an embodiment of the present application. Referring to fig. 4 and 7, in some embodiments, compensation module 152 may include a high pass filter HPF; the compensation module 152 is specifically configured to remove the low-frequency interference signal and the dc offset signal from the ac signal v through the high-pass filter HPF, and obtain a compensated ac signal v; the compensated ac signal v is converted into orthogonal first and second electrical signals v 'and qv' by the phase shift module 151. In this embodiment, a high-pass filter is added after the ac signal v to filter, remove the influence of low frequency or dc bias, and the ac signal v from which low frequency noise is extracted is subjected to the phase shifting module 151 to obtain the first electrical signal v ' and the second electrical signal qv ', where the second electrical signal qv ' is the compensated voltage signal, so as to facilitate improvement of the control accuracy of the electric tool.
FIG. 8 is a schematic diagram of another embodiment of a power tool according to the present application, which may be an angle grinder; the power tool may further include: a collet device 21 and an angle grinder (not shown in fig. 8); the chuck device 21 is connected with one end of the shell 11; the angle grinder piece is detachably connected to the chuck device 21; a motor (not shown in fig. 8) is used to drive the rotation of the chuck assembly 21 such that the chuck assembly 21 rotates the angle grinder plate. The power tool may be a cutter or an angle grinder, etc., and the present embodiment is schematically illustrated with a specific example of the angle grinder. The motor is used for driving the chuck device 21 to rotate, the chuck device 21 can be detachably connected with the angle grinding disc, and then the motor can drag the angle grinding disc to rotate. The angle grinder in this embodiment may be a hand-held angle grinder, and the housing 11 forms an external structure of the angle grinder and also forms a handle for a user to hold.
With continued reference to fig. 8, in some embodiments, the power tool may further include: a shield 23; the shield 23 is partially disposed around the angle plate 22. The shield 23 is mainly provided at a side of the angle grinder piece 22 close to the human body. This effectively prevents debris from splashing to the user and also prevents accidental damage to the angle grinder plate 22 from splashing to the user, which could cause injury to the user.
In some embodiments, the power tool may further include: a circuit board assembly 24 and a heat sink (not shown in fig. 8); the circuit board assembly 24 is provided with a controller or signal processing device 15; the heat sink is disposed against the circuit board assembly 24. The signal processing device 15 and other power devices on the circuit board assembly 24 generate more heat during operation, and the circuit board assembly 24 and the heat dissipation member are attached to each other, so that the heat generated by the circuit board assembly 24 can be effectively transferred.
With continued reference to fig. 8, in some embodiments, the power tool may further include: a connection assembly 25; the connection assembly 25 is used to secure the circuit board assembly 24 to the housing 11. The circuit board assembly 24 is fixed in the threaded hole on the upper housing by a connecting assembly 25, such as a screw, and a person skilled in the art can choose the fixing manner by himself, but the fixing manner of the circuit board assembly 24 to the upper housing is not limited in the present application. The position of the fixed housing of the circuit board assembly 24 is not limited, and a person skilled in the art can select the upper housing, can select the lower housing, or other more suitable positions, so as to enhance the strength of the electric tool, protect the circuit board assembly 24 and the signal processing device 15, reduce the disturbance of the signal processing device 15, and improve the control accuracy of the electric tool.
With continued reference to fig. 8, in some embodiments, the housing 11 may include an inlet 112 and an outlet 113; the inlet 112 is arranged at a position of the housing 11 far from the motor; the air outlet is arranged at one side of the shell away from the air inlet. The inlet port 112 is provided at an end of the lower housing remote from the motor. The air outlet 113 is disposed at an end of the upper housing remote from the inlet 112. A fan can be arranged in the shell, when the fan starts to work, air flow enters the shell 11 from the inlet 112, flows out from the air outlet 113 after flowing through the heat dissipation piece, and takes away most of heat generated by the signal processing device in the working process. It should be noted that the positions of the inlet 112 and the outlet 113 are not limited in the present application, and those skilled in the art can design the present application.
Based on the same idea, the application also provides a method for acquiring phase information of an ac electric signal, as shown in fig. 9, fig. 9 is a flow chart of the method for acquiring phase information of the ac electric signal, where the ac electric signal is used to provide electric energy for an electric tool or an energy storage device, and the method is characterized in that the method comprises the following specific steps:
Step S101, processing the ac electrical signal by the phase shifting module to obtain a first electrical signal and a second electrical signal.
Step S102, processing the first electric signal and the second electric signal through a phase-locked loop module to acquire phase information of an alternating current electric signal; wherein the first electrical signal and the second electrical signal are identical in amplitude and differ in phase angle by 90 °.
The method for acquiring the phase information of the ac electrical signal in this embodiment may be implemented by the electric tool provided by any embodiment of the present application, and includes the technical features of the electric tool provided by any embodiment of the present application, which has the beneficial effects of the corresponding features, and is not described herein again.
Note that the above is only a preferred embodiment of the present application and the technical principle applied. It will be understood by those skilled in the art that the present application is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the application. Therefore, while the application has been described in connection with the above embodiments, the application is not limited to the embodiments, but may be embodied in many other equivalent forms without departing from the spirit or scope of the application, which is set forth in the following claims.
Claims (10)
1. A power tool, comprising:
A housing;
The power supply input device is used for being connected with an alternating current signal so as to provide electric energy required by the electric tool during operation;
A motor;
a drive circuit electrically connected to the motor; the driving circuit is used for driving the motor;
The controller is electrically connected with the driving circuit and is used for outputting a control signal to the driving circuit so as to control the motor to run;
The signal processing device comprises a phase shifting module; the phase shifting module is used for converting the alternating current signal into a first electric signal and a second electric signal; the first electrical signal and the second electrical signal have substantially the same amplitude and have substantially 90 phase angles; the signal processing device is further used for acquiring phase information of the alternating current signal accessed by the power input device according to the first electric signal and the second electric signal;
The controller is configured to regulate the control signal based on the phase information.
2. The power tool of claim 1, wherein the phase shifting module comprises a bandpass filter and a first lowpass filter;
The phase shifting module is used for filtering the alternating current electric signal to obtain a high-frequency interference signal and a low-frequency interference signal through the band-pass filter so as to obtain a first electric signal; the phase shifting module is also used for filtering the alternating current signal to obtain a second electric signal through the first low-pass filter.
3. The power tool of claim 1, wherein the signal processing device further comprises: a compensation module;
the signal processing device is also used for removing the low-frequency interference signal and the direct-current offset signal of the second electric signal through the compensation module to obtain a third electric signal;
The signal processing device is used for acquiring the phase information of the alternating current electric signal according to the first electric signal and the third electric signal.
4. The power tool of claim 3, wherein the signal processing device further comprises: a feedback module;
the feedback module is used for differencing the alternating current signal and the first electric signal and outputting a first difference signal to the phase shifting module; so that the phase shifting module regulates and controls the first electric signal and the second electric signal according to the first difference signal.
5. The power tool of claim 4, wherein the compensation module includes a second low pass filter;
the compensation module is used for compensating the second electric signal after the first difference signal is filtered by the second low-pass filter so as to obtain the third electric signal.
6. The power tool of claim 1, wherein the signal processing device further comprises: a compensation module; the compensation module comprises a high-pass filter;
The compensation module is specifically used for removing a low-frequency interference signal and a direct-current bias signal from the alternating-current electric signal through the high-pass filter to obtain a compensated alternating-current electric signal; and converting the compensated alternating current signal into the first electric signal and the second electric signal through the phase shifting module.
7. The power tool of claim 1, wherein the signal processing device further comprises a phase-locked loop module; the phase-locked loop module is used for accessing the first electric signal and the second electric signal output by the phase-shifting module and outputting phase information of the alternating current signal.
8. The power tool of claim 7, wherein the phase-locked loop module comprises a quadrature phase-locked loop or DQ conversion module.
9. The power tool of claim 1, further comprising: a circuit board assembly and a heat sink;
the circuit board assembly is provided with the controller or the signal processing device; the heat dissipation piece is attached to the circuit board assembly.
10. A method of obtaining phase information of an ac electrical signal for providing electrical energy to a power tool or an energy storage device, the method comprising:
Processing the alternating current signal through a phase shifting module to obtain a first orthogonal or substantially orthogonal electric signal and a second electric signal;
Processing the first electric signal and the second electric signal through a phase-locked loop module to acquire phase information of the alternating current signal; wherein the first electrical signal and the second electrical signal are the same in amplitude and phase angles are substantially 90 degrees apart.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211571516.2A CN118219177A (en) | 2022-12-08 | 2022-12-08 | Electric tool and method for acquiring phase information of alternating current signal |
| PCT/CN2023/135377 WO2024120292A1 (en) | 2022-12-08 | 2023-11-30 | Electric tool and method for acquiring phase information of alternating-current signal |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211571516.2A CN118219177A (en) | 2022-12-08 | 2022-12-08 | Electric tool and method for acquiring phase information of alternating current signal |
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|---|---|
| CN118219177A true CN118219177A (en) | 2024-06-21 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211571516.2A Pending CN118219177A (en) | 2022-12-08 | 2022-12-08 | Electric tool and method for acquiring phase information of alternating current signal |
Country Status (2)
| Country | Link |
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| CN (1) | CN118219177A (en) |
| WO (1) | WO2024120292A1 (en) |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108233818B (en) * | 2016-12-14 | 2020-04-07 | 南京德朔实业有限公司 | Electric tool |
| CN109067393B (en) * | 2018-08-28 | 2021-12-28 | 南方电网科学研究院有限责任公司 | Phase locking method, device and equipment of power system |
| CN109617550B (en) * | 2018-11-27 | 2023-07-07 | 深圳市鼎泰佳创科技有限公司 | Control method of single-phase-locked loop based on second-order generalized integrator |
| EP3751723A1 (en) * | 2019-06-10 | 2020-12-16 | Black & Decker Inc. | Field-oriented sensorless brushless motor control in a power tool |
| CN112202200B (en) * | 2020-09-17 | 2024-02-13 | 西安裕能电力设备有限公司 | Control method and circuit for fast phase tracking compensation |
| CN112803855B (en) * | 2021-01-08 | 2022-06-21 | 北京航空航天大学 | High-precision motor rotor position detection device and method |
-
2022
- 2022-12-08 CN CN202211571516.2A patent/CN118219177A/en active Pending
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2023
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| WO2024120292A1 (en) | 2024-06-13 |
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