Alternating current electric equipment control system and control method

Abstract

The invention relates to an AC electric equipment control system. The system comprises an energy storage module; the rectifying device is used for being connected with a commercial power grid and converting alternating current into direct current; the driving device is connected to the rectifying device so as to receive the direct current from the rectifying device and output a driving signal; the motor is connected to the driving device to rotate in response to the driving signal; the first detection module is connected to the motor to obtain a first signal in the motor; the control device is connected to the first detection module to respond to the first signal and output a first control signal; the switching module is connected to the control device so as to respond to the first control signal and switch whether the energy storage module is connected to the rectifying device or not; the invention further discloses an alternating-current electric equipment control method based on the alternating-current electric equipment control system. The method comprises the steps that the first load current of the electric tool is acquired; when the first load current of the electric tool exceeds a first threshold value, the energy storage module is controlled to be connected to the rectifying device; therefore, the electric tool has the advantages of high and low power.

Description

Technical Field

[0001] The present application relates to the technical field of electric tools, and in particular to a control system and a control method for AC electric equipment. Background Art

[0002] With the development of power tools, users' demand for power of AC power tools has gradually increased, and thus a series of high-power AC power tools have been born.

[0003] In traditional technology, the output power of power tools is subject to certain restrictions, and products can only choose between low power and high power. The reason is that low-power power tools have a high power factor and a long service life, but during their use, they have poor overload resistance and a high temperature rise. High-power power tools have high power, strong overload resistance and low temperature rise, but problems with high-power power tools include low power factor and short service life. A more obvious feature to distinguish low-power and high-power power tools is whether an electrolytic capacitor is connected to the circuit to improve the load resistance.

[0004] Current electric tools cannot combine the characteristics of both low-power and high-power electric tools, and their use is limited. Summary of the invention

[0005] Based on this, it is necessary to provide an AC electric equipment control system and control method to address the problem of limited usage.

[0006] In order to solve the above technical problems, this application is implemented as follows: In one embodiment, an AC electric equipment control system is provided for controlling an electric tool; comprising: Energy storage module; Rectifier, used to connect to the city grid and convert AC power into DC power; A driving device, connected to the rectifying device to receive direct current from the rectifying device and output a driving signal; a motor connected to the drive device to rotate in response to a drive signal; A first detection module, connected to the motor to obtain a first signal from the motor; a control device connected to the first detection module to respond to the first signal and output a first control signal; A switching module is connected to the control device to respond to a first control signal and switch whether the energy storage module is connected to the rectifying device.

[0007] Optionally, the switching module is a first electromagnetic relay; one end of the normally open contact of the first electromagnetic relay is connected to the energy storage module and then to the positive output end of the rectifier device, and the other end is connected to the negative output end of the rectifier device, and the coil of the first electromagnetic relay is controlled by a first control signal.

[0008] Optionally, it further includes a charging module and a second detection module, the second detection module is connected to the control device to output a second signal, and the control device is connected to the charging module to control the charging module to charge the energy storage module in response to the second signal.

[0009] Optionally, the charging module is used to disconnect the circuit where the energy storage module is located after the energy storage module is charged and store electrical energy in the energy storage module.

[0010] Optionally, the charging module is a second electromagnetic relay, the coil of the second electromagnetic relay is controlled by a second signal, the connection point between the energy storage module and the switching module is connected to one end of the normally open contact of the second electromagnetic relay, and the other end of the normally open contact of the second electromagnetic relay is connected to a protective resistor and then connected to the negative output end of the rectifier device.

[0011] Optionally, the charging module has a charging state and a standby state. When the charging module is in the charging state, the charging module controls the energy storage module to charge and store energy; when and only when the charging module is converted from the charging state to the standby state, the energy storage module is allowed to be connected to the rectifier device.

[0012] Optionally, the switching module is used to switch whether the energy storage module is connected to the rectifier device after the charging module stops charging.

[0013] Based on the same inventive concept, the present application also provides an AC electric device control method, which is based on the AC electric device control system disclosed in any of the above embodiments, and includes: Obtaining a first load current of the electric tool; When a first load current of the electric tool exceeds a first threshold, the energy storage module is controlled to be connected to the rectifier device.

[0014] Optionally, the control system further includes a charging module and a micro switch for sensing a switch signal; and before obtaining the load current of the electric tool, the method further includes: Get the signal whether the power tool is powered on; After obtaining a signal that the electric tool is powered on, controlling the charging module to charge the energy storage module; Acquiring a switch signal of the micro switch; After the charging module charges the energy storage module and delays for a preset time and receives the switch signal, controlling the energy storage module to connect to the rectifier device; Control the motor to start.

[0015] Optionally, after controlling the charging module to charge the energy storage module, the step further includes: Acquiring a second load current and a rotation speed of the electric tool; When the second load current exceeds a second threshold and the rotation speed is lower than a third threshold, the circuit where the energy storage module is located is disconnected to maintain the electric energy stored in the energy storage module.

[0016] Optionally, the AC electric equipment control system further includes a charging module; when the first load current of the electric tool exceeds a first threshold, before controlling the energy storage module to be connected to the rectifier device, the control further includes: Control the charging module to charge the energy storage module.

[0017] In an embodiment of the present application, a control device controls the switching module to switch the energy storage module to connect to the rectifier device at a certain timing, so that the circuit can be connected when the load exceeds a certain threshold, so that the electric tool has the advantages of both low-power and high-power electric tools. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic diagram of an AC electric equipment control system in an embodiment of the present application; Figure 2 This is a flow chart of a method for controlling an AC electric device in an embodiment of the present application; Figure 3 This is a flow chart of a method for controlling an AC electric device in another embodiment of the present application.

[0019] Description of the drawings: 100, mains power grid; 101, energy storage module; 102, rectifier; 103, drive device; 104, motor; 105, control device; 106, switching module; 107, charging module. Implementation

[0020] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0021] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0022] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0023] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0024] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being “above”, “above”, and “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0025] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0026] See also Figure 1 FIG1 shows a schematic diagram of an AC electric equipment control system in an embodiment of the present application. An embodiment of the present application provides an AC electric equipment control system, which is used to control an electric tool. The electric equipment control system includes an energy storage module 101, a rectifier 102, a drive device 103, a motor 104, a first detection module, a control device 105 and a switching module 106, wherein the rectifier 102 can be a rectifier bridge rectifier circuit or other rectifier circuits. The rectifier 102 is used to connect to a mains power grid 100, thereby converting the AC power in the mains power grid 100 into DC power.

[0027] The driving device 103 may be a driving circuit for driving the motor 104, and may be a three-phase driving circuit. The driving device 103 may be connected to the rectifier 102, thereby receiving direct current from the rectifier 102 and being controlled by the control device 105 to output a driving signal. The driving signal here may be a driving voltage for driving the motor 104 to rotate. The motor 104 is connected to the driving device 103 and rotates in response to the driving signal, thereby providing power for the electric tool.

[0028] The first detection module is connected to the motor 104 to obtain the first signal in the motor 104. The first signal here can be the load current signal of the motor 104. Of course, it can be understood that the first signal can also be other signals as long as it can reflect the load of the motor 104. The first detection module can be a current detection sensor, or a sampling pin built into the control device 105, or other current detection device, as long as it can detect the current value of the motor 104; the control device 105 is connected to the first detection module to receive the first signal of the first detection module. After responding to the first signal, the control device 105 compares it with the first threshold and outputs the comparison result as the first control signal.

[0029] The control device 105 may be an MCU built into the power tool, or may be other devices for control. The switching module 106 is connected to the control device 105 to receive a first control signal and respond to the first control signal to selectively connect the energy storage module 101 to the rectifier 102. The energy storage module 101 may be an electrolytic capacitor. Before the energy storage module 101 is connected to the rectifier 102, the power tool may be a low-power power tool and output low power; when the energy storage module 101 is connected to the rectifier 102, the power tool may output high power and have a higher overload resistance.

[0030] Preferably, the switching module 106 can be a first electromagnetic relay, one end of the normally open contact of the first electromagnetic relay is connected to the energy storage module 101 and then connected to the positive output end of the rectifier device 102, and the other end is connected to the negative output end of the rectifier device 102. The coil of the first electromagnetic relay is controlled by the first control signal. When the control device 105 outputs the first control signal to the coil of the first electromagnetic relay, the normally open contact of the first electromagnetic relay is closed, thereby connecting the energy storage module 101 to the rectifier device 102.

[0031] Preferably, the electric equipment control system further includes a charging module 107 and a second detection module, the second detection module may be a voltage detection sensor, and the second detection module is used to detect the AC voltage at the front end of the rectifier module and output a second signal. The second detection module is connected to the control device 105 and receives the second signal, and the control device 105 is connected to the charging module 107 to respond to the second signal to control the charging module 107 to charge the energy storage module 101.

[0032] Preferably, the charging module 107 is used to disconnect the circuit where the energy storage module 101 is located after the energy storage module 101 is charged, so that the electric energy can be stored in the energy storage module 101. At this time, after the charging module 107 controls the energy storage module 101 to be charged, the charging module 107 completely disconnects the circuit where the energy storage module 101 is located, and there is no charge discharge in the closed loop power supply capacitor.

[0033] Preferably, the charging module 107 has a charging state and a standby state. When the charging module 107 is in the charging state, the charging module 107 controls the energy storage module 101 to charge and store energy. When and only when the charging module 107 is switched from the charging state to the standby state, the energy storage module 101 is allowed to access the rectifier 102. After the charging module 107 completes charging the energy storage module 101 under the control of the control device 105, the charging module 107 switches from the charging state to the standby state. Only in the standby state is the energy storage module 101 allowed to access the rectifier 102.

[0034] Preferably, the energy storage module 101 is allowed to be connected to the rectifier device 102 only when the switching module 106 is in a standby state after charging the energy storage module 101 under the control of the control device 105. The charging completion here can be that the voltage of the energy storage module 101 reaches the corresponding voltage threshold. At this time, the energy storage module 101 has a certain voltage drop, and the energy storage module 101 will not be broken down after connecting to the rectifier device 102.

[0035] Preferably, the charging module 107 is a second electromagnetic relay, the connection point between the energy storage module 101 and the switching module 106 is connected to one end of the normally open contact of the second electromagnetic relay, and the other end of the normally open contact of the second electromagnetic relay is connected to the protection resistor R1 and then connected to the negative output end of the rectifier 102. The protection resistor R1 limits the current intensity of the energy storage module 101 in the charging state, so that the current is reduced and does not damage the energy storage module 101. The coil of the second electromagnetic relay is controlled by the second signal, and the control device 105 sends a second signal to the coil of the second electromagnetic relay, so that the coil of the second electromagnetic relay closes the normally open contact to control the energy storage module 101 to start charging.

[0036] Combination Figure 2 As shown, FIG2 shows a flow chart of an AC electric device control method in an embodiment of the present application. The control method is based on the above-mentioned AC electric device control system, and the control method specifically includes: Step 210, obtaining the load current of the electric tool.

[0037] Specifically, the control device obtains the load current in the motor, i.e., the first signal, through the first detection module. Since the main output load of the power tool is the motor, the load current of the power tool can be reflected by detecting the load current in the motor. The load current can be used to determine the load condition of the motor. Usually, when the motor is under high load, the load current is large, and when the motor is under low load, the load current is small.

[0038] Step 220: When the load current of the electric tool exceeds a first threshold, the energy storage module is controlled to connect to the rectifier device.

[0039] Specifically, after obtaining the load current of the electric tool, the control device compares the load current with the first threshold value. When the load current of the electric tool exceeds the first threshold value, the control device controls the switching module to connect the energy storage module to the rectifier device. Since the energy storage module can store a certain amount of electric energy, the energy storage module can play the role of smoothing the circuit. At this time, connecting the energy storage module to the rectifier device can improve the load resistance of the entire circuit.

[0040] In some embodiments, in order to facilitate charging and storing energy in the energy storage module, at the same time, the AC electric equipment control system also includes a charging module, a second detection module and a third detection module. The second detection module can be set in a place different from the first detection module. The second detection module is set between the energy storage module and the AC power grid to detect the voltage or current in the AC power grid. The third detection module can be set in a place different from the first detection module and the second detection module. The third detection module is set at both ends of the energy storage module to detect the voltage of the energy storage module. Accordingly, before the above step 210, it also includes: Step 310: Acquire a signal indicating whether the electric tool is powered on.

[0041] Specifically, before connecting the energy storage module to the rectifier device, the control device first obtains a signal indicating whether the power tool is powered on. At this time, the control device obtains a signal from the second detection module, that is, the voltage or current in the AC power grid, thereby obtaining a signal indicating whether the power tool is powered on.

[0042] Step 320: After receiving the power-on signal of the electric tool, the charging module is controlled to charge the energy storage module.

[0043] Specifically, after receiving the power-on signal of the electric tool, the control device controls the charging module to charge the energy storage module. The charging module can be the normally open contact of the electromagnetic relay. Therefore, the control device controls the coil of the electromagnetic relay to energize, and closes the normally open contact so that the energy storage module is connected to the rectifier device for charging. In addition, considering the characteristics of the energy storage module, a current limiting resistor can be connected in series in the charging module to limit the current of the charging module, thereby protecting the energy storage module.

[0044] Step 330, obtaining a switch signal of the micro switch.

[0045] Specifically, after controlling the charging module to charge the energy storage module, the control device obtains a switch signal from a micro switch, which can be arranged at the trigger of the power tool, and the switch signal of the micro switch is triggered by pressing the trigger. The micro switch is connected to the control device to transmit the switch signal to the control device.

[0046] Step 340: After the charging module charges the energy storage module and delays for a preset time and receives a switch signal, the energy storage module is controlled to connect to the rectifier device.

[0047] Specifically, the control device starts delaying after controlling the charging module to charge the energy storage module, and the delay time depends on the charging time of the capacitor. The charging time of the capacitor can be calculated by the capacitance value and the charging speed of the capacitor, or by monitoring the voltage value of the capacitor until it reaches a predetermined value, such as full. After the delay preset time and after receiving the switch signal, the control device controls the energy storage module to connect to the rectifier device. If the delay preset time does not reach the predetermined value, or the switch signal is not received, the control device will not issue an instruction to control the energy storage module to connect to the rectifier device, that is, it will not control the energy storage module to connect to the rectifier device.

[0048] Step 350, controlling the motor to start.

[0049] Specifically, after the energy storage module is connected to the rectifier device, the control device controls the motor to start, at which time the motor is allowed to enter a no-load state or a loaded state. The no-load state can be when the motor starts from a stop to a no-load state, while the loaded state can be when the tool accessories of the power tool have been applied to the work surface, at which time the motor starts from a stop to a loaded state.

[0050] In some embodiments, in order to facilitate the storage of electrical energy in the energy storage module, accordingly, step 320 may further include: Step 360: Obtain a second load current and a rotation speed of the electric tool.

[0051] Specifically, after controlling the charging module to charge the energy storage module, the control device obtains the second load current and the rotation speed of the electric tool. The control device can detect the second load current of the motor through the first detection module and obtain the current rotation speed of the motor through the number of commutations inside the motor. Of course, it is understandable that a rotation speed sensor can also be set on the motor and the data of the rotation speed sensor can be obtained to obtain the current rotation speed of the motor.

[0052] Step 370: When the second load current exceeds the second threshold and the rotation speed is lower than the third threshold, disconnect the circuit where the energy storage module is located to maintain the electric energy stored in the energy storage module.

[0053] Specifically, after the control device obtains the second load current and the rotation speed of the power tool, it compares the second load current with the second threshold and the rotation speed with the third threshold. When the second load current is higher than the second threshold and the rotation speed is lower than the third threshold, the control device controls the charging module and the switching module to disconnect, so that the electric energy is stored in the energy storage module. The charging module and the switching module can be the normally open contacts of the electromagnetic relay, so the control device controls the coil of the electromagnetic relay to be powered off and the normally open contact is disconnected, at which time the discharge circuit of the energy storage module is disconnected. In addition, the electric energy in the energy storage module is stored in the energy storage module. Although the charge of the energy storage module will be slowly released freely in the natural state, it does not form a closed circuit to cause the charge to be discharged rapidly.

[0054] Of course, it is understandable that step 360 to step 370 may be directly located after step 320 . The embodiment of the present application takes the initial startup of the electric tool as an example for explanation. Therefore, step 360 to step 370 are located after step 350 .

[0055] In some embodiments, in order to improve the stability of the energy storage module, the AC electric equipment control system further includes a charging module; accordingly, before step 220, the following steps may also be included: Control the charging module to charge the energy storage module.

[0056] Specifically, before the control device controls the energy storage module to connect to the rectifier device, the control device controls the charging module to charge the energy storage module. At this time, the energy storage module has been charged by the charging module, thereby supplementing the voltage loss that may be generated before the energy storage module is connected to the rectifier device. After the charging module charges the energy storage module, the control device controls the energy storage module to connect to the rectifier device through the switching module. At this time, the charging module charges the energy storage module, thereby maintaining the function of the smoothing circuit and maintaining the overload resistance of the electric tool.

[0057] In some embodiments, after the power tool is powered off, the charge in the energy storage module can be discharged, or the charge in the energy storage module can be stored in the energy storage device. Since the energy storage module can be an electrolytic capacitor, the charge in the electrolytic capacitor can be discharged freely. Therefore, after being placed for a period of time, the charge in the electrolytic capacitor can be released freely. Of course, it is understandable that the control device can also control the switching module and / or the charging module to connect the energy storage module to the rectifier device to discharge the charge.

[0058] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0059] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. An AC electric equipment control system for controlling an electric tool; characterized in that: include: Energy storage module (101); A rectifier (102) for connecting to the city power grid (100) and converting alternating current into direct current; A driving device (103) connected to the rectifying device (102) to receive direct current from the rectifying device (102) and output a driving signal; a motor (104) connected to the driving device (103) to rotate in response to a driving signal; A first detection module connected to the motor (104) to obtain a first signal from the motor (104); A control device (105), connected to the first detection module to respond to the first signal and output a first control signal; A switching module (106) is connected to the control device (105) to respond to a first control signal and switch whether the energy storage module (101) is connected to the rectifying device (102).

2. The AC electric equipment control system according to claim 1, characterized in that: The switching module (106) is a first electromagnetic relay; one end of the normally open contact of the first electromagnetic relay is connected to the energy storage module (101) and then to the positive output end of the rectifier (102), and the other end is connected to the negative output end of the rectifier (102); the coil of the first electromagnetic relay is controlled by a first control signal.

3. The AC electric equipment control system according to claim 1, characterized in that: It also includes a charging module (107) and a second detection module, wherein the second detection module is connected to the control device (105) to output a second signal, and the control device (105) is connected to the charging module (107) to control the charging module (107) to charge the energy storage module (101) in response to the second signal.

4. The AC electric equipment control system according to claim 3, characterized in that: The charging module (107) is used to disconnect the circuit in which the energy storage module (101) is located after the energy storage module (101) has been charged, and to store the electric energy in the energy storage module (101).

5. The AC electric equipment control system according to claim 4, characterized in that: The charging module (107) is a second electromagnetic relay, the coil of the second electromagnetic relay is controlled by a second signal, the connection point between the energy storage module (101) and the switching module (106) is connected to one end of the normally open contact of the second electromagnetic relay, and the other end of the normally open contact of the second electromagnetic relay is connected to the protection resistor R1 and then connected to the negative output end of the rectifier device (102).

6. The AC electric equipment control system according to claim 4, characterized in that: The charging module (107) has a charging state and a standby state. When the charging module (107) is in the charging state, the charging module (107) controls the energy storage module (101) to charge and store energy. When and only when the charging module (107) is converted from the charging state to the standby state, the energy storage module (101) is allowed to be connected to the rectifier device (102).

7. The AC electric equipment control system according to claim 3, characterized in that: The switching module (106) is used to switch whether the energy storage module (101) is connected to the rectifying device (102) after the charging module (107) stops charging.

8. A method for controlling an AC electric device, the method being based on the AC electric device control system according to any one of claims 1 to 7, characterized in that: include: Obtaining a first load current of the electric tool; When a first load current of the electric tool exceeds a first threshold, the energy storage module is controlled to be connected to the rectifier device.

9. The AC electric equipment control method according to claim 8, characterized in that: The control system further includes a charging module and a micro switch for sensing a switch signal; and before obtaining the load current of the electric tool, the method further includes: Get the signal whether the power tool is powered on; After obtaining a signal that the electric tool is powered on, controlling the charging module to charge the energy storage module; Acquiring a switch signal of the micro switch; After the charging module charges the energy storage module and delays for a preset time and receives the switch signal, controlling the energy storage module to connect to the rectifier device; Control the motor to start.

10. The AC electric device control method according to claim 9, characterized in that: After controlling the charging module to charge the energy storage module, the step further includes: Acquiring a second load current and a rotation speed of the electric tool; When the second load current exceeds a second threshold and the rotation speed is lower than a third threshold, the circuit where the energy storage module is located is disconnected to maintain the electric energy stored in the energy storage module.

11. The AC electric device control method according to claim 8, characterized in that: The AC electric equipment control system further includes a charging module; when the first load current of the electric tool exceeds the first threshold, before controlling the energy storage module to be connected to the rectifier device, it also includes: Control the charging module to charge the energy storage module.

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