Electric energy transmission system and control method

Abstract

The invention discloses an electric energy transmission system and a control method. Comprising an inverter, a filter circuit, a transmission cable and a motor, the inverter comprises three phases of output ends, each phase of output end in the three phases of output ends is electrically connected with the first end of the transmission cable through a filter circuit, and the second end of the transmission cable is electrically connected with the motor; the filter circuit comprises a power circuit and a control circuit, the power circuit comprises a first capacitor, a second capacitor, a switching tube assembly, a first switching tube, a second switching tube and a coupling inductor, the first capacitor and the second capacitor are connected in series, a first end of the switching tube assembly is connected between the first capacitor and the second capacitor, and the first switching tube and the second switching tube are connected in series. The second end of the switching tube assembly is connected between the first switching tube and the second switching tube, the second end of the switching tube assembly is electrically connected with one end of the coupling inductor, and the other end of the coupling inductor is electrically connected with the first end of the switching tube assembly.

Description

Technical Field

[0001] The present application belongs to the field of electric energy transmission, and specifically relates to an electric energy transmission system and a control method. Background Art

[0002] In applications where the inverter and motor are far apart, the two need to be connected via a long cable, that is, the inverter and motor need to be connected via a long cable, that is, one end of the cable is connected to the inverter, and the other end of the cable is connected to the motor. Usually, the inverter output voltage waveform has a high dv / dt characteristic. Due to the mismatch between the cable impedance and the motor impedance, the high dv / dt characteristic of the output voltage leads to a transmission line effect in the cable, which in turn causes the motor to generate a reflected voltage, causing the motor winding overvoltage problem, affecting the use of the motor. Summary of the invention

[0003] The purpose of the embodiments of the present application is to provide an electric energy transmission system and control method, which at least solves the problem of transmission line effect in the cable, thereby causing the motor to generate reflected voltage, resulting in overvoltage in the motor winding, and affecting the use of the motor.

[0004] In a first aspect, an embodiment of the present application provides an electric energy transmission system, the electric energy transmission system comprising: an inverter, a filter circuit, a transmission cable, and a motor; The inverter comprises three-phase output terminals, each of which is electrically connected to a first end of the transmission cable through a filter circuit, and a second end of the transmission cable is electrically connected to the motor; The filter circuit includes a power circuit and a control circuit. The power circuit includes a first capacitor, a second capacitor, a switch tube assembly, a first switch tube, a second switch tube and a coupling inductor. The first capacitor is connected in series with the second capacitor. The first end of the switch tube assembly is connected between the first capacitor and the second capacitor. The first switch tube is connected in series with the second switch tube. The second end of the switch tube assembly is connected between the first switch tube and the second switch tube. The second end of the switch tube assembly is electrically connected to one end of the coupling inductor. The other end of the coupling inductor is electrically connected to the first end of the switch tube assembly. The first switch tube is electrically connected to the first capacitor. The second switch tube is electrically connected to the second capacitor. One end of the coupling inductor is electrically connected to the transmission cable. The other end of the coupling inductor is electrically connected to the inverter. The switch tube assembly, the first switch tube and the second switch tube are all connected to the control circuit. The control circuit is used to control the first switch tube, the second switch tube and the switch tube assembly to switch between an on state and an off state when the inverter outputs a voltage wave.

[0005] Optionally, the control circuit is also used for: when the waveform of the voltage wave output from the phase output end of the inverter is at a rising edge, the first switch tube is in a conducting state, and the switch tube assembly and the second switch tube are both in a disconnected state; when the waveform of the voltage wave output from the phase output end of the inverter is at a falling edge, the second switch tube is in a conducting state, and the switch tube assembly and the first switch tube are both in a disconnected state; when the waveform of the voltage wave output from the phase output end of the inverter is at a rising edge for a preset time period, or when the waveform of the voltage wave output from the phase output end of the inverter is at a falling edge for a preset time period, the first switch tube and the second switch tube are in a disconnected state, and the switch tube assembly is in a conducting state.

[0006] Optionally, the control circuit includes a voltage-dividing resistor component, a comparator, a DC power supply, a trigger chip and a driver chip; One end of the voltage-dividing resistor component is electrically connected to the inverter, the other end of the voltage-dividing resistor component is electrically connected to the first input end of the comparator, the second input end of the comparator is electrically connected to one end of the DC power supply, and the other end of the DC power supply is grounded, the output end of the comparator is electrically connected to the trigger chip, the trigger chip is electrically connected to the drive chip, and the control end of the switch tube component, the control end of the first switch tube and the control end of the second switch tube are all connected to the drive chip.

[0007] Optionally, the voltage-dividing resistor component includes a first voltage-dividing resistor and a second voltage-dividing resistor; One end of the first voltage-dividing resistor is electrically connected to the inverter, the other end of the first voltage-dividing resistor is connected to one end of the second voltage-dividing resistor and the first input end of the comparator, and the other end of the second voltage-dividing resistor is grounded.

[0008] Optionally, the switch tube assembly includes a first control switch tube and a second control switch tube; The first end of the first control switch tube is connected between the first capacitor and the second capacitor, the second end of the first control switch is electrically connected to the first end of the second control switch tube, the second end of the second control switch tube is connected between the first switch tube and the second switch tube, and the second end of the second control switch tube is electrically connected to one end of the coupled inductor, and the other end of the coupled inductor is electrically connected to the first end of the first control switch tube.

[0009] Optionally, the coupled inductor includes a primary inductor and a secondary inductor; The primary inductor is coupled to the secondary inductor, one end of the primary inductor is electrically connected to the first end of the switch tube assembly, the other end of the primary inductor is electrically connected to the second end of the switch assembly, one end of the secondary inductor is electrically connected to the transmission inductor, and the other end of the secondary inductor is electrically connected to the inverter.

[0010] Optionally, the inverter has a positive input terminal and a negative input terminal; The positive electrode of the first capacitor is electrically connected to the positive input terminal, the negative electrode of the first capacitor is electrically connected to the positive electrode of the second capacitor, and the negative electrode of the second capacitor is electrically connected to the negative input terminal.

[0011] In a second aspect, an embodiment of the present application provides a control method for controlling the power transmission system according to any one of the first aspects above, the control method comprising: When the inverter outputs a voltage wave, the first switch tube, the second switch tube and the switch tube assembly are controlled to switch between an on state and an off state.

[0012] Optionally, when the inverter outputs a voltage wave, controlling the first switch tube, the second switch tube, and the switch tube assembly to switch between an on state and an off state includes: When the waveform of the voltage wave outputted from the phase output terminal of the inverter is at a rising edge, the first switch tube is in an on state, and the switch tube assembly and the second switch tube are both in an off state; When the waveform of the voltage wave outputted from the phase output terminal of the inverter is at a falling edge, the second switch tube is in an on state, and the switch tube assembly and the first switch tube are both in an off state; When the waveform of the voltage wave output from the phase output end of the inverter is on the rising edge for a preset time period, or when the waveform of the voltage wave output from the phase output end of the inverter is on the falling edge for a preset time period, the first switch tube and the second switch tube are in the off state, and the switch tube assembly is in the on state.

[0013] Optionally, the preset time length is: twice the time length from when the transmission cable receives the voltage wave to when the voltage wave is transmitted to the motor.

[0014] In the embodiment of the present application, since each of the three-phase output ends is electrically connected to the first end of the transmission cable through a filter circuit, and the second end of the transmission cable is electrically connected to the motor, after the inverter outputs the three-phase electricity, the three-phase electricity can be transmitted to the transmission cable through the corresponding filter circuit, and then transmitted to the motor, so that the motor can operate normally. Since the first capacitor and the second capacitor are connected in series, the first end of the switch tube assembly is connected between the first capacitor and the second capacitor, the first switch tube and the second switch tube are connected in series, the second end of the switch tube assembly is connected between the first switch tube and the second switch tube, the first switch tube is electrically connected to the first capacitor, and the second switch tube is electrically connected to the second capacitor, therefore, the first capacitor and the second capacitor can provide electric energy for the filter circuit, and by controlling the first switch tube, the second switch tube and the switch assembly to be turned on or off in different time periods, a positive pulse, a negative pulse or a zero-level pulse can be generated. Since the second end of the switch tube assembly is electrically connected to one end of the coupling inductor, the other end of the coupling inductor is electrically connected to the first end of the switch tube assembly, one end of the coupling inductor is electrically connected to the transmission cable, and the other end of the coupling inductor is electrically connected to the inverter, the generated positive pulse, negative pulse or zero-level pulse can be transmitted to the phase output end of the inverter through the coupling inductor, so that the rising edge and the falling edge of the waveform of the voltage output by the inverter form a two-stage step wave, thereby suppressing the overvoltage of the motor. In addition, by setting a control circuit, it is convenient to control the first switch tube, the second switch tube and the switch tube assembly. That is, in the embodiment of the present application, by setting a coupled inductor, a first switch tube, a second switch tube and a switch tube assembly, and by setting a control circuit, the conduction and disconnection of the first switch tube, the second switch tube and the switch assembly are controlled by the control circuit, so that the generated positive pulse, negative pulse and zero-level pulse can be transmitted to the output side of the inverter through the coupled inductor, so that the rising edge and the falling edge of the waveform of the voltage output by the inverter form a two-step wave form, thereby avoiding the problem of overvoltage in the motor and ensuring that the motor can be used normally. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic diagram showing an electric energy transmission system provided in an embodiment of the present application; Figure 2 A schematic diagram showing a power circuit provided in an embodiment of the present application; Figure 3 A schematic diagram showing a control circuit provided in an embodiment of the present application; Figure 4 A schematic diagram showing a waveform of a voltage output by an inverter provided in an embodiment of the present application; Figure 5 A flow chart showing a control method provided in an embodiment of the present application.

[0016] Reference numerals: 10: inverter; 20: filter circuit; 21: power circuit; 22: control circuit; 211: first capacitor; 212: second capacitor; 213: switch tube assembly; 214: first switch tube; 215: second switch tube; 216: coupling inductor; 221: voltage-dividing resistor assembly; 222: comparator; 223: DC power supply; 224: trigger chip; 225: driver chip; 2131: first control switch tube; 2132: second control switch tube; 2161: primary inductor; 2162: secondary inductor; 2211: first voltage-dividing resistor; 2212: second voltage-dividing resistor; 30: transmission cable; 40: motor. DETAILED DESCRIPTION

[0017] The term "first" or "second" in the specification and claims of this application may include one or more of the features explicitly or implicitly. In the description of this application, unless otherwise specified, "plurality" means two or more. In addition, "and / or" in the specification and claims means at least one of the connected objects, and the character " / " generally means that the objects connected before and after are in an "or" relationship.

[0018] 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.

[0019] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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 it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0020] like Figures 1 to 4 As shown, the power transmission system includes: an inverter 10 , a filter circuit 20 , a transmission cable 30 and a motor 40 .

[0021] The inverter 10 includes a three-phase output end, each of which is electrically connected to a first end of a transmission cable 30 through a filter circuit 20, and a second end of the transmission cable 30 is electrically connected to a motor 40; the filter circuit 20 includes a power circuit 21 and a control circuit 22, the power circuit 21 includes a first capacitor 211, a second capacitor 212, a switch tube assembly 213, a first switch tube 214, a second switch tube 215 and a coupling inductor 216, the first capacitor 211 and the second capacitor 212 are connected in series, the first end of the switch tube assembly 213 is connected between the first capacitor 211 and the second capacitor 212, the first switch tube 214 and the second switch tube 215 are connected in series, and the second end of the switch tube assembly 213 is connected between the first switch tube 214 and the second switch tube 215. The first switch tube 214 is electrically connected to the first capacitor 211, the second switch tube 215 is electrically connected to the second capacitor 212, one end of the coupling inductor 216 is electrically connected to the transmission cable 30, and the other end of the coupling inductor 216 is electrically connected to the inverter 10. The switch tube assembly 213, the first switch tube 214 and the second switch tube 215 are all connected to the control circuit 22. The control circuit 22 is used to control the first switch tube 214, the second switch tube 215 and the switch tube assembly 213 to switch between the on state and the off state when the inverter 10 outputs a voltage wave.

[0022] In the embodiment of the present application, since each of the three-phase output ends is electrically connected to the first end of the transmission cable 30 through a filter circuit 20, and the second end of the transmission cable 30 is electrically connected to the motor 40, after the inverter 10 outputs three-phase electricity, the three-phase electricity can be transmitted to the transmission cable 30 through the corresponding filter circuit 20, and then transmitted to the motor 40, so that the motor 40 can operate normally. Since the first capacitor 211 is connected in series with the second capacitor 212, the first end of the switch tube assembly 213 is connected between the first capacitor 211 and the second capacitor 212, the first switch tube 214 is connected in series with the second switch tube 215, the second end of the switch tube assembly 213 is connected between the first switch tube 214 and the second switch tube 215, the first switch tube 214 is electrically connected to the first capacitor 211, and the second switch tube 215 is electrically connected to the second capacitor 212, therefore, the first capacitor 211 and the second capacitor 212 can provide electric energy for the filter circuit 20, and positive pulses, negative pulses or zero-level pulses can be generated by controlling the conduction or disconnection of the first switch tube 214, the second switch tube 215 and the switch assembly in different time periods. Since the second end of the switch tube assembly 213 is electrically connected to one end of the coupling inductor 216, the other end of the coupling inductor 216 is electrically connected to the first end of the switch tube assembly 213, one end of the coupling inductor 216 is electrically connected to the transmission cable 30, and the other end of the coupling inductor 216 is electrically connected to the inverter 10, the generated positive pulse, negative pulse or zero-level pulse can be transmitted to the phase output end of the inverter 10 through the coupling inductor 216, so that the rising edge and the falling edge of the waveform of the voltage output by the inverter 10 form a two-stage step wave, thereby suppressing the overvoltage of the motor 40. In addition, by setting the control circuit 22, it is convenient to control the first switch tube 214, the second switch tube 215 and the switch tube assembly 213. That is, in the embodiment of the present application, by setting a coupled inductor, a first switch tube 214, a second switch tube 215 and a switch tube assembly 213, and by setting a control circuit 22, the control circuit 22 controls the conduction and disconnection of the first switch tube 214, the second switch tube 215 and the switch assembly, so that the generated positive pulse, negative pulse and zero-level pulse can be transmitted to the output side of the inverter 10 through the coupled inductor 216, so that the rising edge and the falling edge of the waveform of the voltage output by the inverter 10 form a two-step wave form, thereby avoiding the problem of overvoltage in the motor 40 and ensuring that the motor 40 can be used normally.

[0023] It should be noted that in the embodiment of the present application, the first switch tube 214 and the second switch tube 215 can both be MOS tubes, wherein the MOS tube can be an N-type MOS tube or a P-type MOS tube. The specific type of the MOS tube is not limited in the embodiment of the present application.

[0024] In addition, in the embodiment of the present application, the inverter 10 generally includes three-phase output terminals, namely a U-phase output terminal, a V-phase output terminal and a W-phase output terminal, wherein the U-phase output terminal can be connected to a filter circuit 20, the V-phase output terminal can be connected to a filter circuit 20, and the W-phase output terminal can be connected to a filter circuit 20, which is equivalent to connecting three filter circuits 20 to the three-phase output terminals.

[0025] In addition, in some embodiments, the control circuit 22 is also used for: when the waveform of the voltage wave output from the phase output end of the inverter 10 is at a rising edge, the first switch tube 214 is in a conducting state, and the switch tube assembly 213 and the second switch tube 215 are both in a disconnected state; when the waveform of the voltage wave output from the phase output end of the inverter 10 is at a falling edge, the second switch tube 215 is in a conducting state, and the switch tube assembly 213 and the first switch tube 214 are both in a disconnected state; when the waveform of the voltage wave output from the phase output end of the inverter 10 is at a rising edge for a preset time period, or when the waveform of the voltage wave output from the phase output end of the inverter 10 is at a falling edge for a preset time period, the first switch tube 214 and the second switch tube 215 are in a disconnected state, and the switch tube assembly 213 is in a conducting state.

[0026] When the waveform of the voltage wave output from the phase output end of the inverter 10 is on the rising edge, the first switch tube 214 is in the on state, the switch tube assembly 213 and the second switch tube 215 are both in the off state, so that the filter circuit 20 generates a negative pulse, which is then transmitted to the phase output end of the inverter 10 through the coupled inductor 216.

[0027] When the waveform of the voltage wave output from the phase output end of the inverter 10 is at a falling edge, the second switch tube 215 is in an on state, and the switch tube assembly 213 and the first switch tube 214 are both in an off state, so that the filter circuit 20 generates a positive pulse, which is then transmitted to the phase output end of the inverter 10 through the coupled inductor 216.

[0028] When the waveform of the voltage wave output from the phase output end of the inverter 10 is at the rising edge after the preset time length, that is, when the waveform of the voltage wave output from the phase output end of the inverter 10 is at the rising edge, after the preset time length, the first switch tube 214 and the second switch tube 215 are in the disconnected state, the switch tube component 213 is in the on state, and the filter circuit 20 outputs a zero-level pulse, so that the voltage output by the inverter 10 does not change. For example, when the waveform of the voltage wave output from the phase output end of the inverter 10 is at the rising edge at the time point of 01 minutes, and the preset time length is 600 nanoseconds, then at 01 minutes and 600 nanoseconds, the first switch tube 214 and the second switch tube 215 are in the disconnected state, and the switch tube component 213 is in the on state.

[0029] When the waveform of the voltage wave output from the phase output end of the inverter 10 is at the falling edge after the preset time length, that is, when the waveform of the voltage wave output from the phase output end of the inverter 10 is at the falling edge, the first switch tube 214 and the second switch tube 215 are in the disconnected state, the switch tube component 213 is in the on state, and the filter circuit 20 outputs a zero-level pulse, so that the voltage output by the inverter 10 does not change. For example, when the waveform of the voltage wave output from the phase output end of the inverter 10 is at the falling edge at the time point of 02 minutes, and the preset time length is 600 nanoseconds, at 02 minutes and 600 nanoseconds, the first switch tube 214 and the second switch tube 215 are in the disconnected state, and the switch tube component 213 is in the on state.

[0030] In addition, the coupling inductor 216 transmits a positive pulse to the phase output terminal of the inverter 10, so that the rising edge of the voltage output by the inverter 10 forms a two-stage step wave form, and the coupling inductor 216 transmits a negative pulse to the phase output terminal of the inverter 10, so that the falling edge of the voltage output by the inverter 10 forms a two-stage step wave form. The voltage output by the inverter 10 is in the form of a pulse, with a rising edge and a falling edge. For example, Figure 4 As shown in the figure, U in The waveform of the initial voltage outputted by the inverter 10 is shown as U LM The waveform of the voltage transmitted from the filter circuit 20 to the phase output terminal of the inverter 10 is represented by U out The waveform of the voltage at the phase output terminal of the inverter 10 and the waveform of the voltage after the pulse transmitted by the coupled inductor 216 is superimposed, U mot The waveform represents the voltage of the motor 40. By forming a two-stage step wave, the reflected voltage of the first stage step wave and the reflected voltage of the second stage step wave can cancel each other, thereby suppressing the reflected voltage of the motor 40 and preventing the motor 40 from overvoltage.

[0031] In addition, in some embodiments, the control circuit 22 includes a voltage-dividing resistor component 221, a comparator 222, a DC power supply 223, a trigger chip 224 and a driving chip 225; one end of the voltage-dividing resistor component 221 is electrically connected to the inverter 10, the other end of the voltage-dividing resistor component 221 is electrically connected to the first input end of the comparator 222, the second input end of the comparator 222 is electrically connected to one end of the DC power supply 223, and the other end of the DC power supply 223 is grounded, the output end of the comparator 222 is electrically connected to the trigger chip 224, the trigger chip 224 is electrically connected to the driving chip 225, and the control end of the switch tube component 213, the control end of the first switch tube 214 and the control end of the second switch tube 215 are all connected to the driving chip 225.

[0032] The first input end of the comparator 222 may be a positive input end of the comparator 222, that is, a non-inverting input end of the comparator 222, and the second input end of the comparator 222 may be a negative input end of the comparator 222, that is, a non-inverting output end of the comparator 222. In addition, when the first switch tube 214 and the second switch tube 215 are both MOS tubes, the gate of the first switch tube 214 and the gate of the second switch tube 215 are both electrically connected to the driving chip 225, and the driving chip 225 drives the first switch tube 214 and the second switch tube 215 to switch between the on state and the off state, and the control end of the switch tube assembly 213 is electrically connected to the driving chip 225, and the driving chip 225 drives the switch tube assembly 213 to switch between the on state and the off state.

[0033] In addition, in the embodiment of the present application, one end of the voltage-dividing resistor component 221 is electrically connected to the phase output end of the inverter 10, so that the voltage wave output by the inverter 10 can be transmitted to the voltage-dividing resistor component 221, and then transmitted to the comparator 222. The comparison is performed by the comparator 222, so that the comparator 222 can output a comparison signal. Once the comparison signal is transmitted to the trigger chip 224, the trigger chip 224 can generate a trigger signal. The trigger signal is transmitted to the drive chip 225, so that the drive chip 225 controls the first switch tube 214, the second switch tube 215 and the switch tube component 213.

[0034] In addition, in the embodiment of the present application, the voltage-dividing resistor component 221 includes a first voltage-dividing resistor 2211 and a second voltage-dividing resistor 2212; one end of the first voltage-dividing resistor 2211 is electrically connected to the inverter 10, the other end of the first voltage-dividing resistor 2211 is connected to one end of the second voltage-dividing resistor 2212 and the first input end of the comparator 222, and the other end of the second voltage-dividing resistor 2212 is grounded.

[0035] It should be noted that the number of the first voltage-dividing resistors 2211 can be set according to actual needs. For example, the number of the first voltage-dividing resistors 2211 is 1. For another example, the number of the first voltage-dividing resistors 2211 is 2. At this time, the two first voltage-dividing resistors 2211 can be connected in series, and one end of one first voltage-dividing resistor 2211 is electrically connected to the first input end of the comparator 222, and one end of the other first voltage-dividing resistor 2211 is electrically connected to the inverter 10. The specific number of the first voltage-dividing resistors 2211 is not limited in the embodiment of the present application. In addition, the number of the second voltage-dividing resistors 2212 can also be set according to actual needs. For example, the number of the second voltage-dividing resistors 2212 is 1. For another example, the number of the second voltage-dividing resistors 2212 is 2, and the two second voltage-dividing resistors 2212 are connected in series. The specific number of the second voltage-dividing resistors 2212 is not limited in the embodiment of the present application. In addition, the number of the first voltage-dividing resistors 2211 and the number of the second voltage-dividing resistors 2212 can be determined by determining the resistance value of the voltage-dividing resistor component 221. For example, if a resistance value of 10 kilo-ohms is required at the position of the first voltage-dividing resistor 2211, a 10 kilo-ohm resistor can be selected as the first voltage-dividing resistor 2211, which is equivalent to a number of 1 first voltage-dividing resistor. Alternatively, two 5 kilo-ohm resistors can be selected as the first voltage-dividing resistor 2211, which is equivalent to two first voltage-dividing resistors 2211 connected in series. Similarly, the number of the second voltage-dividing resistors 2212 can also be determined by determining the resistance value of the voltage-dividing resistor component 221, which will not be described in detail here.

[0036] In addition, in some embodiments, the switch tube assembly 213 includes a first control switch tube 2131 and a second control switch tube 2132; the first end of the first control switch tube 2131 is connected between the first capacitor 211 and the second capacitor 212, the second end of the first control switch is electrically connected to the first end of the second control switch tube 2132, the second end of the second control switch tube 2132 is connected between the first switch tube 214 and the second switch tube 215, and the second end of the second control switch tube 2132 is electrically connected to one end of the coupling inductor 216, and the other end of the coupling inductor 216 is electrically connected to the first end of the first control switch tube 2131.

[0037] It should be noted that the first control switch tube 2131 and the second control switch tube 2132 can both be MOS tubes, wherein the gate of the first control switch tube 2131 and the gate of the second control switch tube 2132 are both electrically connected to the control circuit 22 .

[0038] In addition, in some embodiments, the coupled inductor 216 includes a primary inductor 2161 and a secondary inductor 2162; the primary inductor 2161 is coupled to the secondary inductor 2162, one end of the primary inductor 2161 is electrically connected to the first end of the switch tube assembly 213, the other end of the primary inductor 2161 is electrically connected to the second end of the switch assembly, one end of the secondary inductor 2162 is electrically connected to the transmission inductor, and the other end of the secondary inductor 2162 is electrically connected to the inverter 10.

[0039] Through such a setting, once the filter circuit 20 generates a positive pulse, the positive pulse can be transmitted to the primary inductor 2161, and coupled to the secondary inductor 2162 through the primary inductor 2161, so that the secondary inductor 2162 transmits the positive pulse to the phase output end of the inverter 10; similarly, the negative pulse generated by the filter circuit 20 can also be transmitted to the primary inductor 2161, and coupled to the secondary inductor 2162 through the primary inductor 2161, so that the secondary inductor 2162 transmits the negative pulse to the phase output end of the inverter 10, and the zero-level pulse generated by the filter circuit 20 can also be transmitted to the primary inductor 2161, and coupled to the secondary inductor 2162 through the primary inductor 2161, so that the secondary inductor 2162 transmits the zero-level pulse to the phase output end of the inverter 10.

[0040] In addition, in some embodiments, the inverter 10 has a positive input terminal and a negative input terminal; the positive electrode of the first capacitor 211 is electrically connected to the positive input terminal, the negative electrode of the first capacitor 211 is electrically connected to the positive electrode of the second capacitor 212, and the negative electrode of the second capacitor 212 is electrically connected to the negative input terminal. Through such a configuration, electric energy can be transferred to the first capacitor 211 and the second capacitor 212, so that the first capacitor 211 and the second capacitor 212 can be charged, so that the first capacitor 211 and the second capacitor 212 can supply power to the filter circuit 20.

[0041] The present application embodiment provides a control method for controlling the power transmission system in any of the above embodiments, such as Figure 5 As shown, the control method includes: Step 501: When the inverter outputs a voltage wave, control the first switch tube, the second switch tube and the switch tube assembly to switch between an on state and an off state.

[0042] Among them, the inverter can be detected in real time. Once the inverter output voltage wave is detected, the first switch tube, the second switch tube and the switch tube assembly can be controlled, that is, the first switch tube, the second switch tube and the switch tube assembly can be switched between the on state and the off state.

[0043] In addition, in some embodiments, step 501 may be implemented as follows: when the waveform of the voltage wave output from the phase output terminal of the inverter is at a rising edge, the first switch tube is in an on state, and the switch tube assembly and the second switch tube are both in an off state; when the waveform of the voltage wave output from the phase output terminal of the inverter is at a falling edge, the second switch tube is in an on state, and the switch tube assembly and the first switch tube are both in an off state; when the waveform of the voltage wave output from the phase output terminal of the inverter is at a rising edge for a preset time period, or when the waveform of the voltage wave output from the phase output terminal of the inverter is at a falling edge for a preset time period, the first switch tube and the second switch tube are in an off state, and the switch tube assembly is in an on state.

[0044] Among them, when it is determined that the voltage waveform at the phase output end of the inverter is at the rising edge, the first switch tube can be controlled to be turned on, and the switch tube assembly and the second switch tube can be turned off, and the duration of the first switch tube being turned on can be controlled to be a preset duration, and the duration of the switch tube assembly and the second switch tube being turned off can be controlled to be a preset duration, which is equivalent to making the first switch tube remain in the on state for a preset duration, and the duration of the switch tube assembly and the second switch tube remain in the off state for a preset duration; thereafter, the first switch tube and the second switch tube can be controlled to be turned off, and the switch tube assembly can be turned on, that is, after the first switch tube remains in the on state for a preset duration, and the switch tube assembly and the second switch tube remain in the off state for a preset duration, the switch tube assembly is controlled to be turned on.

[0045] When the voltage waveform output from the phase output end of the inverter is at a falling edge, the second switch tube can be controlled to be turned on, and the switch tube assembly and the first switch tube are both turned off, and the duration of the second switch tube being turned on can be controlled to be a preset duration, and the duration of the switch tube assembly and the first switch tube being turned off can be controlled to be a preset duration, which is equivalent to making the second switch tube remain in the on state for a preset duration, and the duration of the switch tube assembly and the first switch tube remain in the off state for a preset duration; thereafter, the first switch tube and the second switch tube can be controlled to be turned off, and the switch tube assembly can be turned on, that is, after the second switch tube remains in the on state for a preset duration, and the switch tube assembly and the first switch tube remain in the off state for a preset duration, the switch tube assembly is controlled to be turned on.

[0046] It should be noted that when the phase output terminal of the inverter outputs a voltage wave, the first switch tube, the second switch tube and the switch tube assembly can be continuously controlled.

[0047] In addition, in the embodiment of the present application, the preset time length is: twice the time length from when the transmission cable receives the voltage wave to when it transmits the voltage wave to the motor.

[0048] The pulse width t of the positive and negative pulses generated by the filter circuit d Should be twice the cable transmission time tt ;

[0049] in, l ca is the cable length, v ca is the transmission speed of the cable; when When the motor is in a state of reverse polarity, the reflected voltages of the motors can cancel each other out, thereby suppressing the overvoltage of the motors.

[0050] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0051] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. An electric energy transmission system, characterized in that: The electric energy transmission system comprises: an inverter, a filter circuit, a transmission cable and a motor; The inverter comprises three-phase output terminals, each of which is electrically connected to a first end of the transmission cable through one of the filter circuits, and a second end of the transmission cable is electrically connected to the motor; The filter circuit includes a power circuit and a control circuit. The power circuit includes a first capacitor, a second capacitor, a switch tube assembly, a first switch tube, a second switch tube and a coupling inductor. The first capacitor is connected in series with the second capacitor. The first end of the switch tube assembly is connected between the first capacitor and the second capacitor. The first switch tube is connected in series with the second switch tube. The second end of the switch tube assembly is connected between the first switch tube and the second switch tube. The second end of the switch tube assembly is electrically connected to one end of the coupling inductor. The other end of the coupling inductor is electrically connected to the first end of the switch tube assembly. The first switch tube is electrically connected to the first capacitor. The second switch tube is electrically connected to the second capacitor. One end of the coupling inductor is electrically connected to the transmission cable. The other end of the coupling inductor is electrically connected to the inverter. The switch tube assembly, the first switch tube and the second switch tube are all connected to the control circuit. The control circuit is used to control the first switch tube, the second switch tube and the switch tube assembly to switch between an on state and an off state when the inverter outputs a voltage wave.

2. The power transmission system according to claim 1, characterized in that: The control circuit is further used for: when the waveform of the voltage wave outputted from the phase output terminal of the inverter is at a rising edge, the first switch tube is in a conducting state, and the switch tube assembly and the second switch tube are both in a disconnected state; when the waveform of the voltage wave outputted from the phase output terminal of the inverter is at a falling edge, the second switch tube is in a conducting state, and the switch tube assembly and the first switch tube are both in a disconnected state; When the waveform of the voltage wave output from the phase output end of the inverter is on the rising edge for a preset time period, or when the waveform of the voltage wave output from the phase output end of the inverter is on the falling edge for a preset time period, the first switch tube and the second switch tube are in the off state, and the switch tube assembly is in the on state.

3. The power transmission system according to claim 1, characterized in that: The control circuit includes a voltage-dividing resistor component, a comparator, a DC power supply, a trigger chip and a driver chip; One end of the voltage-dividing resistor component is electrically connected to the inverter, the other end of the voltage-dividing resistor component is electrically connected to the first input end of the comparator, the second input end of the comparator is electrically connected to one end of the DC power supply, and the other end of the DC power supply is grounded, the output end of the comparator is electrically connected to the trigger chip, the trigger chip is electrically connected to the drive chip, and the control end of the switch tube component, the control end of the first switch tube and the control end of the second switch tube are all connected to the drive chip.

4. The power transmission system according to claim 3, characterized in that: The voltage-dividing resistor component includes a first voltage-dividing resistor and a second voltage-dividing resistor; One end of the first voltage-dividing resistor is electrically connected to the inverter, the other end of the first voltage-dividing resistor is connected to one end of the second voltage-dividing resistor and the first input end of the comparator, and the other end of the second voltage-dividing resistor is grounded.

5. The power transmission system according to any one of claims 1 to 4, characterized in that: The switch tube assembly includes a first control switch tube and a second control switch tube; The first end of the first control switch tube is connected between the first capacitor and the second capacitor, the second end of the first control switch is electrically connected to the first end of the second control switch tube, the second end of the second control switch tube is connected between the first switch tube and the second switch tube, and the second end of the second control switch tube is electrically connected to one end of the coupled inductor, and the other end of the coupled inductor is electrically connected to the first end of the first control switch tube.

6. The power transmission system according to any one of claims 1 to 4, characterized in that: The coupled inductor includes a primary inductor and a secondary inductor; The primary inductor is coupled to the secondary inductor, one end of the primary inductor is electrically connected to the first end of the switch tube assembly, the other end of the primary inductor is electrically connected to the second end of the switch assembly, one end of the secondary inductor is electrically connected to the transmission inductor, and the other end of the secondary inductor is electrically connected to the inverter.

7. The power transmission system according to any one of claims 1 to 4, characterized in that: The inverter has a positive input terminal and a negative input terminal; The positive electrode of the first capacitor is electrically connected to the positive input terminal, the negative electrode of the first capacitor is electrically connected to the positive electrode of the second capacitor, and the negative electrode of the second capacitor is electrically connected to the negative input terminal.

8. A control method, characterized in that: Used to control the power transmission system according to any one of claims 1 to 7, the control method comprising: When the inverter outputs a voltage wave, the first switch tube, the second switch tube and the switch tube assembly are controlled to switch between an on state and an off state.

9. The control method according to claim 8, characterized in that: When the inverter outputs a voltage wave, controlling the first switch tube, the second switch tube, and the switch tube assembly to switch between an on state and an off state includes: When the waveform of the voltage wave outputted from the phase output terminal of the inverter is at a rising edge, the first switch tube is in an on state, and the switch tube assembly and the second switch tube are both in an off state; When the waveform of the voltage wave outputted from the phase output terminal of the inverter is at a falling edge, the second switch tube is in an on state, and the switch tube assembly and the first switch tube are both in an off state; When the waveform of the voltage wave output from the phase output end of the inverter is on the rising edge for a preset time period, or when the waveform of the voltage wave output from the phase output end of the inverter is on the falling edge for a preset time period, the first switch tube and the second switch tube are in the off state, and the switch tube assembly is in the on state.

10. The control method according to claim 9, characterized in that: The preset time length is: twice the time length from when the transmission cable receives the voltage wave to when the voltage wave is transmitted to the motor.

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