A frequency converter overcurrent protection device and a frequency converter

Abstract

The application relates to the technical field of frequency converters, and discloses a frequency converter overcurrent protection device and a frequency converter, which comprise an instrument assembly, the instrument assembly comprises a frequency converter shell, a breaking assembly is arranged on the inner side of the frequency converter shell, the breaking assembly comprises a connecting plate, a sliding block is arranged on the top of the connecting plate, a moving contact and a connecting plate are fixedly connected to the top of the sliding block, a sleeve is fixedly connected to the top end of the connecting plate, a horizontal rod one is rotatably sleeved to the inner side of the sleeve, the moving contact keeps closed under the pre-pressure of a spring when the current is normal, the system inertia of the breaking assembly is utilized through cooperation with the connecting plate, the circuit inertia delay and the quick breaking of the circuit are realized when the circuit overflows, the sleeve and the horizontal rod one are designed in a spiral shape, the moving contact drives the horizontal rod one to rotate under the pushing of electromagnetic repulsion, the problem that the frequency converter cannot effectively identify the two overflows in time and the phenomenon of frequent false breaking often occurs and the circuit is disturbed is solved.

Description

Technical Field

[0001] This invention relates to the field of frequency converter technology, and more specifically to a frequency converter overcurrent protection device and a frequency converter. Background Technology

[0002] Inverters are core components in industrial and civilian equipment for regulating motor speed. Their core function is to change the power supply frequency and voltage of an AC motor, thereby precisely controlling its speed, rather than ensuring the motor always runs at its rated speed. The inverter converts the input AC power to DC power, smooths the converted DC to reduce current fluctuations, and finally converts the stable DC back into AC power with adjustable frequency and voltage for output to the motor. The overcurrent protection device of the inverter is not a separate component but an integrated protection module. Its core function is to prevent the main circuit current from exceeding the rated value, avoiding damage to the inverter's power components or the motor. There are two types of overcurrent phenomena in reality: one is instantaneous inrush current, the most typical of which is… The first type of overcurrent is the stall current at the moment of motor startup. At this time, the current is very large, reaching 5-7 times the rated current, but the duration is extremely short, between tens and hundreds of milliseconds. This is an inherent characteristic of motor startup, which is normal and must be allowed; otherwise, the motor cannot start. The second type is the continuous fault current, including short-circuit current and severe overload current. These are faults that must be cut off immediately or quickly. However, existing frequency converters cannot effectively identify these two types of overcurrent in a timely manner, often resulting in false tripping, which causes trouble for the circuit. In addition, the frequency converter generates too much heat, requiring additional power for heat dissipation in addition to the power required for equipment operation, resulting in a large amount of power consumption. Therefore, we propose a frequency converter overcurrent protection device and frequency converter to solve the above problems. Summary of the Invention

[0003] In order to overcome the above-mentioned defects of the prior art, the present invention provides an overcurrent protection device for a frequency converter and a frequency converter to solve the problems existing in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: an overcurrent protection device for a frequency converter, comprising an instrument assembly, the instrument assembly including a frequency converter housing, a disconnection assembly installed on the inner side of the frequency converter housing, the disconnection assembly including a connecting plate, a slider installed on the top of the connecting plate, a moving contact and the connecting plate fixedly connected to the top of the slider, a sleeve fixedly connected to the top of the connecting plate, and a crossbar rotatably sleeved on the inner side of the sleeve; The moving contact remains closed under the preload of the spring when the current is normal. Through cooperation with the connecting plate, the system inertia of the disconnecting assembly is utilized to delay and quickly disconnect the circuit inertia when the circuit is overcurrent. Both the sleeve and the crossbar adopt a spiral design, which allows the moving contact to drive the crossbar to rotate under the push of electromagnetic repulsion, thereby improving the heat dissipation and sealing of the frequency converter.

[0005] Furthermore, an external interface one is fixedly connected to the inner side of the top of the inverter housing. A disconnection assembly is electrically connected to the bottom of the external interface one. A main circuit assembly is electrically connected to the bottom of the disconnection assembly. A control circuit component is electrically connected to the bottom of the main circuit assembly. The back of the control circuit component is electrically connected to the control display screen. An external interface two is electrically connected to the bottom of the control circuit component, and the external interface two is fixedly connected to the inner side of the bottom of the inverter housing.

[0006] Furthermore, the splitting assembly includes a connecting plate, with supporting side plates fixedly connected to both ends of the top of the connecting plate, and a rail plate fixedly connected to one side of the bottom of the two splitting assemblies facing each other, with two sliders slidably sleeved on the side of the rail plate.

[0007] Furthermore, springs are fixedly connected to one side of each of the two sliders, and the other ends of the two springs are respectively fixedly connected to one side of the two supporting side plates. Moving contacts are fixedly connected to the top of each of the two sliders. One end of the moving contact is provided with a groove, and the other ends of the two moving contacts are electrically connected to wires. Connecting plates are fixedly connected to the top of each of the two sliders, and sleeves are fixedly connected to the top of each of the two connecting plates. A crossbar is rotatably sleeved on the inner side of each of the two sleeves. The two ends of the crossbar pass through the two supporting side plates respectively, and a cooling fan blade is fixedly connected to one end of the crossbar. A gear is fixedly connected to the other end of the crossbar. The inner side of the sleeve is spiral, and the side of the crossbar is spiral.

[0008] Furthermore, an installation strip is fixedly connected to the front end of the top of the connecting plate, a data cable is electrically connected to the front of the installation strip, and two conductor rods are electrically connected to the top of the installation strip. A stationary contact is fixedly connected to the top of each of the two conductor rods, and one end of the stationary contact is attached to the sliding groove.

[0009] Furthermore, the front of the two supporting side plates is provided with several heat dissipation grooves, and the front of the two supporting side plates is fixedly sleeved with bearings. The inner side of the two bearings is rotatably sleeved with a crossbar two. One end of the crossbar two is fixedly connected with a gear two, and the gear two meshes with a gear one. The middle part of the crossbar two is fixedly sleeved with a conical wheel one.

[0010] A frequency converter uses an overcurrent protection device as described above, wherein a guide bar is fixedly connected to the top of the blank board assembly, a data cable is electrically connected to the top of the guide bar, and two wires are electrically connected to the bottom of the guide bar.

[0011] Furthermore, a rear cover assembly is fixedly connected to the back of the instrument assembly, and a control display screen is fixedly connected to the front of the inverter housing. The control display screen consists of a digital display screen, an adjustment knob, and control buttons. There are six control buttons arranged in two rows and three columns. The digital display screen and the adjustment knob are located above the control buttons and are adjacent to each other.

[0012] Furthermore, the rear cover assembly includes a dustproof shell, with a rotating shaft rotatably sleeved on the inner side of the dustproof shell. One end of the rotating shaft is fixedly connected to a second conical wheel, which meshes with a first conical wheel. The other end of the rotating shaft is fixedly connected to a third gear.

[0013] Furthermore, two fixed plates are fixedly connected to the back of the dustproof shell, and movable plates are slidably connected to the back of each of the two fixed plates. A round rod is fixedly connected to one side of the two movable plates facing each other. A toothed plate is provided on one side of the movable plate, and the teeth mesh with the gears in a triple engagement.

[0014] The technical effects and advantages of this invention are as follows: 1. This system utilizes the electromagnetic force generated by the current flowing through the moving contact. The moving contact is connected to a wire and fixed to the top of the slider, held closed by a preloaded spring. When the current is normal, the electromagnetic force is insufficient to overcome the spring preload. The large current at startup generates a strong instantaneous electromagnetic repulsion force, which pushes the moving contact away. Due to the large mechanical inertia of the entire disconnecting assembly caused by the moving contact being connected to the crossbar, the brief repulsion pulse cannot effectively displace the slider, leaving it stationary. When a circuit fault occurs, the continuous overcurrent generates a continuous electromagnetic repulsion force, which counteracts the spring force and inertial force. This continuous electromagnetic force causes the moving contact to displace, thereby pushing the slider to move and causing the moving contact to separate from the stationary contact, thus achieving disconnection. This solves the problem that existing frequency converters cannot effectively identify these two types of overcurrent in a timely manner, often resulting in false disconnections and causing circuit problems.

[0015] 2. The moving contact pushes the slider to move. The movement of the slider, under the helical action of the connecting plate and the first crossbar, realizes the rotation of the first crossbar, thereby driving the cooling fan blades to rotate and providing kinetic energy to the cooling fan blades. No other electrical energy is required in the process, avoiding the problem of existing frequency converters needing to provide additional electrical energy for heat dissipation, which causes a large amount of electrical energy consumption. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the overall rear structure of the present invention; Figure 3 This is a schematic diagram of the instrument component structure of the present invention; Figure 4 This is a schematic diagram of the rear structure of the instrument assembly of the present invention; Figure 5 This is a schematic diagram of the segmentation component structure of the present invention; Figure 6 This is a schematic diagram of the side structure of the splitting component of the present invention; Figure 7 This is a schematic cross-sectional view of the hollow plate assembly of the present invention; Figure 8 This is a schematic diagram of the front structure of the rear cover assembly of the present invention; Figure 9 This is a schematic diagram of the back structure of the rear cover assembly of the present invention.

[0017] The attached figures are labeled as follows: 1. Instrument assembly; 101. Inverter housing; 102. Control display screen; 103. External interface one; 104. Disconnection assembly; 1041. Connecting plate; 1042. Support side plate; 1043. Slider; 1044. Moving contact; 1045. Connecting plate; 1046. Stationary contact; 1047. Empty plate assembly; 1048. Cooling fan blade; 105. Main circuit assembly; 106. Control circuit components; 107. External interface two; 2. Rear cover assembly; 201. Dustproof housing; 202. Rotating shaft; 203. Fixed plate; 204. Movable plate. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. In addition, the forms of the various structures described in the following embodiments are merely illustrative. The inverter overcurrent protection device and inverter involved in the present invention are not limited to the structures described in the following embodiments. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Reference Figure 1 and Figure 2 The present invention provides an overcurrent protection device for a frequency converter and a frequency converter, including an instrument assembly 1, wherein a back cover assembly 2 is fixedly connected to the back of the instrument assembly 1.

[0020] In this embodiment, it is necessary to further explain that the instrument component 1 solves the problem that the existing frequency converter cannot effectively identify these two types of overcurrent in a timely manner, often resulting in false tripping and causing trouble for the circuit. The rear cover component 2 improves the heat dissipation of the entire device by utilizing the instrument component 1. The specific structure and working principle of the above components will be explained in detail later.

[0021] Reference Figure 3 and Figure 4The instrument assembly 1 includes a frequency converter housing 101. A control display screen 102 is fixedly connected to the front of the frequency converter housing 101. An external interface 103 is fixedly connected to the inner side of the top of the frequency converter housing 101. A disconnection assembly 104 is electrically connected to the bottom of the external interface 103. A main circuit assembly 105 is electrically connected to the bottom of the disconnection assembly 104. A control circuit component 106 is electrically connected to the bottom of the main circuit assembly 105. The back of the control circuit component 106 is electrically connected to the control display screen 102. An external interface 107 is electrically connected to the bottom of the control circuit component 106, and the external interface 107 is fixedly connected to the inner side of the bottom of the frequency converter housing 101.

[0022] In this embodiment, it is necessary to further explain that the control display screen 102 consists of a digital display screen, an adjustment knob, and control buttons. There are six control buttons arranged in two rows and three columns. The digital display screen and the adjustment knob are located above the control buttons and are adjacent to each other.

[0023] Reference Figures 5 to 7 The splitting assembly 104 includes a connecting plate 1041. Supporting side plates 1042 are fixedly connected to both ends of the top of the connecting plate 1041. A rail plate is fixedly connected to the opposite side of the bottom ends of the two splitting assemblies 104. Two sliders 1043 are slidably sleeved on the side of the rail plate. A spring is fixedly connected to one side of each slider 1043, and the other ends of the two springs are respectively fixedly connected to one side of the two supporting side plates 1042. A movable contact 1044 is fixedly connected to the top of each slider 1043. One end is provided with a sliding groove, and the other ends of the two moving contacts 1044 are electrically connected to wires. The tops of the two sliders 1043 are fixedly connected to connecting plates 1045, and the tops of the two connecting plates 1045 are fixedly connected to sleeves. A crossbar is rotatably sleeved on the inner side of the two sleeves. The two ends of the crossbar pass through the two supporting side plates 1042 respectively, and a heat dissipation fan blade 1048 is fixedly connected to one end of the crossbar. A gear is fixedly connected to the other end of the crossbar. The inner side of the sleeve is spiral, and the side of the crossbar is spiral. An installation strip is fixedly connected to the front end of the top of the connecting plate 1041. A data cable is electrically connected to the front of the installation strip. Two conductor rods are electrically connected to the top of the installation strip. A stationary contact 1046 is fixedly connected to the top of each of the two conductor rods. One end of the stationary contact 1046 is attached to the sliding groove. The front of the two supporting side plates 1042 is provided with several heat dissipation grooves. The front of the two supporting side plates 1042 is fixedly sleeved with bearings. The inner side of the two bearings is rotatably sleeved with a crossbar 2. One end of the crossbar 2 is fixedly connected with a gear 2, and the gear 2 meshes with a gear 1. The middle part of the crossbar 2 is fixedly sleeved with a conical wheel 1. The top of the empty board assembly 1047 is fixedly connected to a guide strip, the top of the guide strip is electrically connected to a data cable 2, and the bottom of the guide strip is electrically connected to two wires. Electromagnetic force is generated by the current flowing through the moving contact 1044. The moving contact 1044 is connected to a wire and fixed to the top of the slider. It is kept closed by a preload spring. When the current is normal, the electromagnetic force is insufficient to overcome the spring preload. The large current at startup generates a strong instantaneous electromagnetic repulsion force, which pushes the moving contact 1044 away. Because the moving contact 1044 is connected to the crossbar, the mechanical inertia of the entire disconnecting assembly 104 is large. The brief repulsion pulse cannot effectively displace the slider, so it remains stationary. When there is a circuit fault, the continuous overcurrent generates a continuous electromagnetic repulsion force, which counteracts the spring force and inertial force. The continuous electromagnetic force causes the moving contact 1044 to displace, which in turn pushes the slider 1043 to move, causing the moving contact 1044 to separate from the stationary contact 1046, thus achieving disconnection. This solves the problem that existing frequency converters cannot effectively identify these two types of overcurrent in a timely manner, often resulting in false disconnection and causing circuit problems.

[0024] In this embodiment, it is necessary to specifically explain that the inner side of the sleeve and the side of the crossbar are spirally designed. When the sleeve moves, the meshing and squeezing between the spiral threads causes the crossbar to rotate due to the lateral thrust. The preload of the spring is set to 1.5 to 2 times the electromagnetic force generated by the rated current to ensure that the moving contact remains closed under normal current and instantaneous impact current. The moving contact 1044 and the stationary contact 1046 are made of silver-based composite material, which has low contact resistance and high arc resistance, and extends service life. The blades of the cooling fan 1048 are made of aluminum alloy and coated with a high-emissivity coating to enhance heat dissipation efficiency. The helical mating surface of the crossbar and the sleeve is coated with lubricant to reduce friction loss and improve transmission efficiency.

[0025] The moving contact 1044 pushes the slider 1043 to move. The movement of the slider, under the spiral action of the connecting plate 1045 and the crossbar, causes the crossbar to rotate, thereby driving the cooling fan blade 1048 to rotate and providing kinetic energy to the cooling fan blade 1048. No other electrical energy is required in the process, avoiding the problem of existing frequency converters needing to provide additional electrical energy for heat dissipation, which causes a large amount of electrical energy consumption.

[0026] Reference Figure 8 and Figure 9The rear cover assembly 2 includes a dustproof shell 201. A rotating shaft 202 is rotatably sleeved on the inner side of the dustproof shell 201. One end of the rotating shaft 202 is fixedly connected to a conical wheel 2, which meshes with a conical wheel 1. The other end of the rotating shaft 202 is fixedly connected to a gear 3. Two fixed plates 203 are fixedly connected to the back of the dustproof shell 201. Movable plates 204 are slidably connected to the back of each of the two fixed plates 203. A round rod is fixedly connected to one side of each of the two movable plates 204 facing each other. A toothed plate is provided on one side of each movable plate 204, and the teeth mesh with the gear 3.

[0027] In this embodiment, it should be specifically explained that the meshing of bevel teeth one and bevel teeth two causes the crossbar two to rotate, which in turn causes the rotating shaft 202 to rotate, thereby causing the movable plate 204 to move upward and increasing the sealing of the back of the dustproof shell 201.

[0028] The working principle of this invention is as follows: Electromagnetic force is generated by the current flowing through the moving contact 1044. The moving contact 1044 is connected to a wire and fixed to the top of the slider. It is kept closed by a preload spring. When the current is normal, the electromagnetic force is insufficient to overcome the spring preload. The large current at startup generates a strong instantaneous electromagnetic repulsion force, which pushes the moving contact 1044 away. Because the moving contact 1044 is connected to the crossbar, the mechanical inertia of the entire disconnecting assembly 104 is very large. The brief repulsion pulse cannot effectively displace the slider, thus keeping it stationary. When there is a circuit fault, the continuous overcurrent generates a continuous electromagnetic repulsion force, which counteracts the spring force and inertial force. The continuous electromagnetic force causes the moving contact 1044 to displace, thereby pushing the slider 1043 to move, causing the moving contact 1044 to separate from the stationary contact 1046, thus achieving disconnection. This solves the problem that existing frequency converters cannot effectively identify these two types of overcurrent in a timely manner, often resulting in false disconnections and causing circuit problems. The moving contact 1044 pushes the slider 1043 to move. The movement of the slider, under the spiral action of the connecting plate 1045 and the crossbar, causes the crossbar to rotate, thereby driving the cooling fan blade 1048 to rotate and providing kinetic energy to the cooling fan blade 1048. No other electrical energy is required in the process, avoiding the problem of existing frequency converters needing to provide additional electrical energy for heat dissipation, which causes a large amount of electrical energy consumption.

[0029] Finally, the following points should be noted: First, in the description of this application, it should be noted that, unless otherwise specified and limited, the terms "installation", "connection", and "linkage" should be interpreted broadly, and can be mechanical or electrical connections, or internal connections between two components, or direct connections. "Up", "down", "left", "right", etc. are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may change. Secondly: The accompanying drawings of the embodiments disclosed in this invention only involve the structures involved in the embodiments disclosed in this invention. Other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of this invention can be combined with each other. In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An overcurrent protection device for a frequency converter, comprising an instrument assembly (1), characterized in that, The instrument assembly (1) includes a frequency converter housing (101), and a disconnection assembly (104) is installed on the inner side of the frequency converter housing (101). The disconnection assembly (104) includes a connecting plate (1041), a slider (1043) is installed on the top of the connecting plate (1041), a moving contact (1044) and a connecting plate (1045) are fixedly connected to the top of the slider (1043), a sleeve is fixedly connected to the top of the connecting plate (1045), and a crossbar is rotatably sleeved on the inner side of the sleeve. The moving contact (1044) remains closed to (1056) under the preload of the spring when the current is normal. Through cooperation with the connecting plate (1045), the circuit inertia is delayed and quickly disconnected when the circuit is overcurrent, utilizing the system inertia of the disconnecting assembly (104). Both the sleeve and the crossbar adopt a spiral design, which allows the moving contact (1044) to drive the crossbar to rotate under the push of electromagnetic repulsion, thereby improving the heat dissipation and sealing of the frequency converter.

2. The inverter overcurrent protection device according to claim 1, characterized in that: An external interface one (103) is fixedly connected to the inner side of the top of the inverter housing (101). The bottom of the external interface one (103) is electrically connected to a disconnection assembly (104). The bottom of the disconnection assembly (104) is electrically connected to a main circuit assembly (105). The bottom of the main circuit assembly (105) is electrically connected to a control circuit component (106). The back of the control circuit component (106) is electrically connected to a control display screen (102). The bottom of the control circuit component (106) is electrically connected to an external interface two (107), and the external interface two (107) is fixedly connected to the inner side of the bottom of the inverter housing (101).

3. The inverter overcurrent protection device according to claim 2, characterized in that: The splitting assembly (104) includes a connecting plate (1041), and both ends of the top of the connecting plate (1041) are fixedly connected to supporting side plates (1042). The bottom ends of the two splitting assemblies (104) are fixedly connected to a rail plate on one side facing each other, and two sliders (1043) are slidably sleeved on the side of the rail plate.

4. The inverter overcurrent protection device according to claim 3, characterized in that: Springs are fixedly connected to one side of each of the two sliders (1043), and the other ends of the two springs are fixedly connected to one side of each of the two support side plates (1042). Moving contacts (1044) are fixedly connected to the top of each of the two sliders (1043). One end of the moving contact (1044) is provided with a groove, and the other end of the two moving contacts (1044) is electrically connected to a wire. Connecting plates (1045) are fixedly connected to the top of each of the two sliders (1043). Sleeves are fixedly connected to the top of each of the two connecting plates (1045). A crossbar is rotatably sleeved on the inner side of each of the two sleeves. The two ends of the crossbar pass through the two support side plates (1042) respectively, and a cooling fan blade (1048) is fixedly connected to one end of the crossbar. A gear is fixedly connected to the other end of the crossbar. The inner side of the sleeve is spiral, and the side of the crossbar is spiral.

5. The inverter overcurrent protection device according to claim 4, characterized in that: An installation strip is fixedly connected to the front end of the top of the connecting plate (1041). A data cable is electrically connected to the front of the installation strip. Two conductor rods are electrically connected to the top of the installation strip. A stationary contact (1046) is fixedly connected to the top of each of the two conductor rods. One end of the stationary contact (1046) is attached to the sliding groove.

6. The inverter overcurrent protection device according to claim 5, characterized in that: The front of the two support side plates (1042) is provided with several heat dissipation grooves. The front of the two support side plates (1042) is fixedly sleeved with bearings. The inner side of the two bearings is rotatably sleeved with a crossbar two. One end of the crossbar two is fixedly connected with a gear two, and the gear two meshes with a gear one. The middle part of the crossbar two is fixedly sleeved with a conical wheel one.

7. A frequency converter using an overcurrent protection device as described in claim 6, characterized in that: The top of the empty board assembly (1047) is fixedly connected to a guide bar, the top of the guide bar is electrically connected to a data cable, and the bottom of the guide bar is electrically connected to two wires.

8. A frequency converter according to claim 7, characterized in that: The back cover assembly (2) is fixedly connected to the back of the instrument assembly (1), and the control display screen (102) is fixedly connected to the front of the inverter housing (101). The control display screen (102) consists of a digital display screen, an adjustment knob, and control buttons. There are six control buttons arranged in two rows and three columns. The digital display screen and the adjustment knob are located above the control buttons and are adjacent to each other.

9. A frequency converter according to claim 8, characterized in that: The rear cover assembly (2) includes a dustproof shell (201), and a rotating shaft (202) is rotatably sleeved on the inner side of the dustproof shell (201). One end of the rotating shaft (202) is fixedly connected to a second conical wheel, and the second conical wheel meshes with a first conical wheel. The other end of the rotating shaft (202) is fixedly connected to a third gear.

10. A frequency converter according to claim 9, characterized in that: The dustproof housing (201) has two fixed plates (203) fixedly connected to its back side. The back of each of the two fixed plates (203) is slidably connected to a movable plate (204). A round rod is fixedly connected to one side of each of the two movable plates (204) facing each other. A toothed plate is provided on one side of each movable plate (204), and the teeth mesh with the gears.

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