Electric field coupling type wireless electric energy transmission system and transmission method based on three-phase cylindrical coupling mechanism

Abstract

The invention discloses an electric field coupling type wireless power transmission system based on a three-phase cylindrical coupling mechanism, which is formed by sequentially connecting a direct current input power supply, a three-phase inverter circuit, a primary side LCLC resonance compensation network, a cylindrical coupling mechanism, a secondary side LCLC resonance compensation network, a three-phase rectifying circuit and a voltage reduction circuit, and the cylindrical coupling mechanism is used as the core of the system. The invention further discloses an electric field coupling type wireless power transmission method based on the three-phase cylindrical coupling mechanism. According to the cylindrical coupling design, the anti-offset performance under the rotation or position deviation condition is improved, and it is ensured that efficient energy transfer can be maintained even under the non-ideal alignment condition.

Description

Technical Field

[0001] The present invention belongs to the technical field of wireless power transfer, and particularly relates to an electric field coupled wireless power transfer system based on a three-phase cylindrical coupling mechanism, and an electric field coupled wireless power transfer method based on a three-phase cylindrical coupling mechanism. Background Art

[0002] Wireless Power Transfer (WPT) technology is a method that can achieve power transfer without physical wire connection. With the continuous progress of power electronics technology, power equipment and electrical products have penetrated into every corner of life. Although some devices can rely on battery power supply, most electrical appliances still need to be connected to the power source through wires. However, in many cases, the presence of physical cables limits the convenience and flexibility of device use. Therefore, wireless power transfer technology emerges as a solution that can complete energy supply without wires.

[0003] In recent years, WPT technology has attracted wide attention globally. This technology has revolutionized the traditional wired power transfer mode, getting rid of the dependence on physical cables, enabling charging devices to be separated from the power supply, and the charging system and the power supply system can be respectively encapsulated, thus solving problems such as exposed wires, contact point sparks, and inconvenient movement in traditional power transfer. In addition, in extreme environments or special application scenarios, WPT technology shows unique advantages. Although WPT technology is developing rapidly, there are still many challenges to be solved in theoretical research and practical applications.

[0004] Currently, the research on wireless power transfer mainly focuses on magnetic field coupling methods. However, traditional magnetic field coupled wireless power transfer has problems such as strong electromagnetic interference, sensitivity to metal foreign objects, fast attenuation of transmission efficiency with distance, and its coupling components are usually bulky and costly. On the other hand, existing electric field coupling technologies mostly adopt single-phase or bipolar plate structures, with small coupling capacitance, low power density, and uneven electric field distribution, which easily leads to leakage current and energy loss. Therefore, in order to overcome these limitations, it is necessary to develop a new type of coupling mechanism to achieve more efficient wireless power transfer. Summary of the Invention

[0005] The object of the present invention is to provide an electric field coupled wireless power transfer system based on a three-phase cylindrical coupling mechanism. The cylindrical coupling design improves the anti-offset performance under rotation or position deviation conditions, ensuring efficient energy transfer even under non-ideal alignment conditions.

[0006] Another object of the present invention is to provide an electric field coupled wireless power transfer method based on a three-phase cylindrical coupling mechanism.

[0007] The first technical solution adopted by the present invention is an electric field coupling type wireless power transmission system based on a three-phase cylindrical coupling mechanism, which is composed of a DC input power supply, a three-phase inverter circuit, a primary side LCLC resonance compensation network, a cylindrical coupling mechanism, a secondary side LCLC resonance compensation network, a three-phase rectifier circuit, and a buck circuit connected in sequence. The cylindrical coupling mechanism is the core of the system.

[0008] The characteristics of the first technical solution of the present invention also lie in that

[0009] The specific structure of the cylindrical coupling mechanism is as follows: it includes a transmitting electrode plate and a receiving electrode plate. The transmitting electrode plate is composed of 3 arc-shaped metal plates. Specifically, the transmitting electrode plate includes a transmitting electrode plate P1, a transmitting electrode plate P2, and a transmitting electrode plate P3. The receiving electrode plate is composed of 3 arc-shaped metal plates. The receiving electrode plate includes a receiving electrode plate P4, a receiving electrode plate P5, and a receiving electrode plate P6. The receiving electrode plate is placed inside the transmitting electrode plate to form a cylindrical structure. The receiving electrode plates P4, P5, and P6 are installed on the inner wall of the intelligent robot shell, and the transmitting electrode plates P1, P2, and P3 are installed on the wireless charging device.

[0010] The receiving electrode plate P4 is placed inside the transmitting electrode plate P1, the receiving electrode plate P5 is placed inside the transmitting electrode plate P2, and the receiving electrode plate P6 is placed inside the transmitting electrode plate P3. The distance between the transmitting electrode plate and the receiving electrode plate is 0.5 cm to 1.5 cm.

[0011] The primary side LCLC resonance compensation network and the secondary side LCLC resonance compensation network have the same structure, both including six compensation inductors and six compensation capacitors. One end of the 3 compensation inductors L f1 、L f2 、L f3 of the primary side LCLC resonance compensation network are all connected to the bridge arm of the three-phase inverter circuit. The other ends of the 3 compensation inductors L f1 、L f2 、L f3 are all connected in parallel with the compensation capacitors C f1 、C f2 、C f3 , and are also connected to the first ends of the other 3 compensation inductors L 1 、L 2 、L 3 . The ends of the compensation inductors L 1 、L 2 、L 3 are connected in parallel with the compensation capacitors C p1 、C p2 、C p3 . The compensation inductors L 1 、L 2 、L 3The ends are respectively and correspondingly connected to the transmitting plates P1, P2, and P3 of the cylindrical coupling mechanism, and the first three compensation inductors L of the secondary LCLC resonance compensation network 4 , L 5 , L 6 The first ends are respectively and correspondingly connected to the receiving plates P4, P5, and P6 of the cylindrical coupling mechanism. The first three compensation inductors L 4 , L 5 , L 6 The first ends are also respectively connected in parallel with three compensation capacitors C p4 , C p5 , C p6 The first three compensation inductors L 4 , L 5 , L 6 The ends are respectively connected in parallel with the compensation capacitors C f1 , C f2 , C f3 and are connected to the first ends of the last three compensation inductors L f4 , L f5 , L f6 The first ends of the last three compensation inductors L f4 , L f5 , L f6 The ends are respectively and correspondingly connected to the midpoints of the bridge arms of the three-phase rectifier circuit.

[0012] The three-phase inverter circuit is a three-phase voltage source bridge inverter circuit, which is composed of six switching tubes. The switching tubes are divided into two groups, with three switching tubes in each group. The first group includes switching tube Q 1 , switching tube Q 2 , switching tube Q 3 , and the second group includes switching tube Q 4 , switching tube Q 5 , switching tube Q 6 , corresponding to the three-phase outputs respectively. The three-phase outputs are also connected to the primary LCLC resonance compensation network. The DC input power supply is connected to the input end of the three-phase inverter circuit, converting the DC power generated by the power supply into high-frequency three-phase alternating current.

[0013] The specific structure of the three-phase rectifier circuit is: it is composed of six switching tubes S 1 , S 2 , S 3 , S 4 , S 5 , S 6 , divided into three groups, corresponding to the three phases. Each group has two switching tubes, which are respectively the upper and lower bridge arms of the switching tubes of the three-phase full-bridge rectifier circuit. Among them, switching tube S 1 , switching tube S 4 are a group, and switching tube S 2 , switching tube S 5are grouped as one set, switching transistor S 3 , switching transistor S 6 are grouped as one set. The compensation inductors of the secondary side LCLC resonant compensation network are respectively connected to the midpoints of the three bridge arms of the rectifier circuit, and the output of the three-phase rectifier circuit is also connected to the buck circuit.

[0014] The buck circuit is a DC-DC converter.

[0015] The second technical solution adopted by the present invention is an electric field coupling type wireless power transmission method based on a three-phase cylindrical coupling mechanism, which is specifically as follows:

[0016] The radius R of the main side plate of the cylindrical coupling mechanism 1 is 300 mm, the radius R of the secondary side plate 2 is 270 mm, the height h of the metal plate is 600 mm, the central angle θ of the metal plate is 100°, and the relationships among the dielectric constant, temperature and angular frequency of the electromagnetic wave are as follows:

[0017]

[0018] In the formula:

[0019] ε ∞ (S,T) is the limit value of the dielectric constant at high frequencies;

[0020] ε 0 is the dielectric coefficient of free space;

[0021] f is the frequency of the electromagnetic wave;

[0022] ε S (S,T) is the static dielectric constant of air;

[0023] δ(S,T) is the ionic conductivity;

[0024] τ(S,T) is the Debye relaxation time.

[0025] The characteristics of the second technical solution of the present invention also lie in that

[0026] The coupling capacitor C of the cylindrical coupling mechanism M is expressed as:

[0027]

[0028] In the formula:

[0029] ε 0 is the dielectric constant of the dielectric between the plates;

[0030] a is the semi-major axis of the elliptic cylinder formed by the curved plate;

[0031] b is the semi-minor axis of the elliptic cylinder formed by the curved plate;

[0032] c is the semi-focal length of the elliptic cylinder formed by the curved panel;

[0033] α is the central angle of the curved metal plate.

[0034] If the curved metal plate is converted into a symmetric cylindrical capacitor, where a = b and c = 0, then the coupling capacitor C M is expressed as:

[0035]

[0036] When the relative position of the plates is offset, the coupling capacitance decreases.

[0037] Simplify the three-phase system to a single-phase system and further simplify this circuit to a π-type network as follows:

[0038] The input and output voltages of phase A are defined as V 1 and V 2 , and the input and output currents are defined as I 1 and I 2 . Regarding the coupling mechanism as a two-port network, the input-output relationship is as follows:

[0039]

[0040] The input-output relationship of the π-type circuit model is also expressed as:

[0041]

[0042] The equivalent coupling capacitance parameters are obtained by solving the simultaneous equations (4) and (5):

[0043]

[0044] Therefore, the equivalent input capacitors C in.Tx and C in.Rx at the receiver and transmitter are expressed as:

[0045]

[0046] The relationship between the resonance network parameters is expressed as:

[0047]

[0048] Finally, substitute the measured capacitance values between each pair of plates into the formula to obtain the value of the compensation inductor, completing the design of the compensation network;

[0049] By controlling the conduction and cutoff of six switching tubes composed of metal-oxide-semiconductor field-effect transistors, different phase voltage outputs are obtained. When the control signal indicates that a certain switching tube conducts, the corresponding drive circuit applies a positive voltage to the gate of the switching tube, and this positive voltage forms a conductive channel between the gate and the source, allowing current to flow from the drain to the source.

[0050] The beneficial effects of the present invention are as follows: (1) Compared with the traditional magnetic field coupling wireless power transmission method, the electric field coupling wireless power transmission system adopted by the present invention significantly reduces heat loss. Since this system relies on the electric field rather than the magnetic field for energy transfer, it will not generate eddy current loss or leakage magnetic field in a complex environment, nor is it affected by the piezomagnetic effect caused by changes in magnetic permeability. These characteristics ensure that the electric field coupling wireless power transmission system is safer and more reliable during operation. (2) The present invention introduces a unique multi-phase cylindrical coupling mechanism composed of six curved metal plates. Each pair of electrode plates is respectively connected to one phase of the three-phase alternating current. This design not only improves the mutual capacitance between the coupling structures, but also greatly enhances the power transmission efficiency and capacity of the system. By optimizing the electric field distribution, more efficient energy transmission is achieved, thus providing stronger support for applications. (3) This new type of cylindrical coupling mechanism is particularly suitable for application scenarios that require high flexibility, such as intelligent robots. It not only improves the anti-offset ability of the system under rotational misalignment, ensuring stable energy transmission even under non-ideal alignment conditions, but also its compact design allows the receiver side to be easily integrated into the internal space of the intelligent robot. This not only improves the overall performance of the system, but also effectively reduces the external space required for installation, providing an efficient and space-saving power transmission solution for intelligent devices. Brief Description of the Drawings

[0051] Figure 1 is a schematic diagram of the three-phase cylindrical coupling mechanism involved in the present invention;

[0052] Figure 2(a) shows the change of the coupling capacitance when the coupling plate rotates in the present invention;

[0053] Figure 2(b) shows the change of the coupling capacitance when the coupling plate vertically offsets in the present invention;

[0054] Figure 3 is an equivalent model diagram of the capacitance based on the three-phase cylindrical coupling mechanism involved in the present invention;

[0055] Figure 4 is a principle block diagram of the electric field coupling wireless power transmission circuit based on the three-phase cylindrical coupling mechanism involved in the present invention. Detailed Description of the Invention

[0056] The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0057] This system consists of a DC input power supply, a three-phase inverter circuit, an LCLC resonant compensation network, a cylindrical coupling mechanism, a three-phase rectifier circuit, and a buck circuit. Specifically, the DC input power supply is connected to the input end of the three-phase inverter circuit, which is used to convert the input direct current into high-frequency three-phase alternating current. The output of this three-phase inverter circuit is then connected to the primary resonant network and is connected to the transmitting plate through this network. The transmitting plate is a cylindrical coupling structure composed of three arc-shaped metal plates (P1, P2, P3). It realizes the wireless transfer of energy from the transmitting end to the receiving end through the generated high-frequency alternating electric field. On the receiving end, the receiving plate is connected to the secondary resonant network, responsible for receiving the energy coupled through the electric field and transferring it to the three-phase rectifier circuit. The rectifier circuit is used to convert the received alternating current back into direct current, and then the buck circuit is used for voltage stabilization to ensure that the finally output electric energy is stable and reliable for use by the load.

[0058] The electric field coupling type wireless power transmission system of the present invention based on a three-phase cylindrical coupling mechanism has a structure as Figure 4 shown, which is composed of a DC input power supply, a three-phase inverter circuit, a primary LCLC resonant compensation network, a cylindrical coupling mechanism, a secondary LCLC resonant compensation network, a three-phase rectifier circuit, and a buck circuit connected in sequence. The cylindrical coupling mechanism is the core of the system.

[0059] Combined with Figure 1 , the specific structure of the cylindrical coupling mechanism is as follows: It includes a transmitting plate and a receiving plate. The transmitting plate is composed of 3 arc-shaped metal plates. Specifically, the transmitting plate includes transmitting plate P1, transmitting plate P2, and transmitting plate P3. The receiving plate is composed of 3 arc-shaped metal plates. The receiving plate includes receiving plate P4, receiving plate P5, and receiving plate P6. The receiving plate is placed inside the transmitting plate to form a cylindrical structure. Receiving plate P4, receiving plate P5, and receiving plate P6 are installed on the inner wall of the intelligent robot shell, and transmitting plate P1, transmitting plate P2, and transmitting plate P3 are installed on the wireless charging device.

[0060] Receiving plate P4 is placed inside transmitting plate P1, receiving plate P5 is placed inside transmitting plate P2, and receiving plate P6 is placed inside transmitting plate P3. The distance between the transmitting plate and the receiving plate is 0.5 cm to 1.5 cm. The optimal state is achieved when the distance is 1 cm.

[0061] The primary LCLC resonant compensation network and the secondary LCLC resonant compensation network have the same structure, both including six compensation inductors and six compensation capacitors. Three compensation inductors L f1 、L f2 、L f3One end of each is connected to the arm of the three-phase inverter circuit, and the other ends of the three compensation inductors L f1 、L f2 、L f3 are all connected in parallel with the compensation capacitors C f1 、C f2 、C f3 Meanwhile, they are also connected to the first ends of another three compensation inductors L 1 、L 2 、L 3 The first ends of the compensation inductors L 1 、L 2 、L 3 are connected to the first ends of the compensation capacitors C p1 、C p2 、C p3 in parallel. The ends of the compensation inductors L 1 、L 2 、L 3 are respectively connected to the transmitting plates P1, P2, and P3 of the cylindrical coupling mechanism. The first three compensation inductors L 4 、L 5 、L 6 of the secondary LCLC resonant compensation network are respectively connected to the receiving plates P4, P5, and P6 of the cylindrical coupling mechanism. The first three compensation inductors L 4 、L 5 、L 6 are also respectively connected to the first ends of the three compensation capacitors C p4 、C p5 、C p6 in parallel. The ends of the first three compensation inductors L 4 、L 5 、L 6 are respectively connected to the first ends of the compensation capacitors C f1 、C f2 、C f3 in parallel and are connected to the first ends of the last three compensation inductors L f4 、L f5 、L f6 The ends of the last three compensation inductors L f4 、L f5 、L f6 are respectively connected to the midpoints of the arms of the three-phase rectifier circuit. The secondary LCLC resonant compensation network is connected to the three-phase rectifier circuit to convert the transmitted alternating current into direct current, and then connected to the buck circuit to transmit the stable electric energy to the load.

[0062] The three-phase inverter circuit is a three-phase voltage source bridge inverter circuit, which consists of six switching tubes. The switching tubes are divided into two groups, with three switching tubes in each group. The first group includes the switching tube Q 1 、the switching tube Q 2 、the switching tube Q3 , the second group includes switching transistors Q 4 , switching transistor Q 5 , switching transistor Q 6 , respectively corresponding to three-phase outputs, and the three-phase outputs are also connected to the original primary LCLC resonance compensation network. The DC input power supply is connected to the input end of the three-phase inverter circuit, converting the DC power generated by the power supply into high-frequency three-phase alternating current.

[0063] The specific structure of the three-phase rectifier circuit is: composed of six switching transistors S 1 , S 2 , S 3 , S 4 , S 5 , S 6 , divided into three groups corresponding to the three phases. Each group has two switching transistors, which are respectively the upper and lower bridge arms of the switching transistors of the three-phase full-bridge rectifier circuit. Among them, switching transistor S 1 , switching transistor S 4 are a group, switching transistor S 2 , switching transistor S 5 are a group, switching transistor S 3 , switching transistor S 6 are a group. The compensation inductors of the secondary LCLC resonance compensation network are respectively connected to the midpoints of the three bridge arms of the rectifier circuit, and the output of the three-phase rectifier circuit is also connected to the buck circuit.

[0064] The buck circuit is a DC-DC converter.

[0065] The electric field coupling type wireless power transmission method based on the three-phase cylindrical coupling mechanism of the present invention is as follows:

[0066] The radius R 1 of the main side plate of the cylindrical coupling mechanism is 300 mm, the radius R 2 of the secondary side plate is 270 mm, the height h of the metal plate is 600 mm, and the central angle θ of the metal plate is 100°. For the air medium, the dielectric constant value determines the size of the coupling capacitor. The relationship between the dielectric constant, temperature and the angular frequency of the electromagnetic wave is as follows:

[0067]

[0068] In the formula:

[0069] ε ∞ (S,T) is the limit value of the dielectric constant at high frequencies;

[0070] ε 0 is the dielectric coefficient of free space;

[0071] f is the frequency of the electromagnetic wave;

[0072] εS (S, T) is the static dielectric constant of air;

[0073] δ(S, T) is the ionic conductivity;

[0074] τ(S, T) is the Debye relaxation time.

[0075] The coupling capacitance C of the cylindrical coupling mechanism M is expressed as:

[0076]

[0077] In the formula:

[0078] ε 0 is the dielectric constant of the dielectric between the plates;

[0079] a is the semi-major axis of the elliptic cylinder formed by the curved plate;

[0080] b is the semi-minor axis of the elliptic cylinder formed by the curved plate;

[0081] c is the semi-focal length of the elliptic cylinder formed by the curved plate;

[0082] α is the central angle of the curved metal plate.

[0083] If the curved metal plate is converted into a symmetric cylindrical capacitor, where a = b and c = 0, then the coupling capacitor C M is expressed as:

[0084]

[0085] It can be seen from the above analysis that the coupling capacitance value involved in the present invention is not only related to the dielectric constant of the dielectric between the plates, but also related to the central angle of the curved metal plate. It is different from the traditional coupling mechanism.

[0086] As shown in Figure 2, when there is an offset between the coupling plates, the coupling capacitance value changes. Among them, (a) shows the change of the coupling capacitance when the coupling plates rotate, and (b) shows the change of the coupling capacitance when the coupling plates are vertically offset. When the relative position of the plates is offset, the coupling capacitance decreases. When the rotation angle is 10 degrees, the coupling capacitance decreases from 143 pf to 133 pf. When the rotation is 20 degrees, it decreases to 121 pf. When the rotation is 60 degrees, it decreases to 61 pf. When the vertical offset distance is 5 cm, the coupling capacitance decreases from 143 pf to 138 pf, to 126 pf when it is 10 cm, and to 81 pf when it is 30 cm.

[0087] As Figure 3As shown, the circuit topology and coupling mechanism of the electric field coupling power transmission system involved in the present invention are three-phase symmetrical, which means that the circuit structure and interaction mode of the three phases are the same. Therefore, when analyzing, the three-phase system can be simplified into a single-phase system, and the circuit can be further simplified into a π-type network. Such network simplification helps to more clearly understand the power transmission mechanism of the system, thereby performing more effective performance analysis and design optimization. The details are as follows:

[0088] The input and output voltage of phase A is defined as V 1 and V 2 , the input and output current is defined as I 1 and I 2 , considering the coupling mechanism as a two-port network, the input-output relationship is as follows:

[0089]

[0090] The input-output relationship of the π-type circuit model is also expressed as:

[0091]

[0092] By combining equations (4) and (5), the equivalent coupling capacitance parameters are obtained:

[0093]

[0094] Therefore, the equivalent input capacitor C at the receiver and transmitter in.Tx and C in.Rx It is expressed as:

[0095]

[0096] The relationship between the resonant network parameters is expressed as:

[0097]

[0098] Finally, the measured capacitance values ​​between the plates are substituted into the formula to obtain the compensation inductance value, thus completing the design of the compensation network.

[0099] like Figure 4 As shown, in the electric field coupling wireless power transmission circuit involved in the present invention, the DC power supply is converted into high-frequency three-phase AC power after passing through a full-bridge inverter network. The three-phase voltage-type bridge inverter circuit is composed of six switching tubes, which are divided into two groups. Each group has three switching tubes, corresponding to the three-phase output respectively.

[0100] By controlling the conduction and cutoff of six switching tubes composed of metal-oxide-semiconductor field-effect transistors (MOSFETs), different phase voltage outputs are obtained. When the control signal indicates that a certain switching tube conducts, the corresponding drive circuit applies a positive voltage to the gate of the switching tube, and this positive voltage forms a conductive channel between the gate and the source, allowing current to flow from the drain to the source.

[0101] Embodiment 1

[0102] The electric-field-coupled wireless power transmission system of the present invention based on a three-phase cylindrical coupling mechanism has a structure as Figure 4 shown, which is composed of a DC input power supply, a three-phase inverter circuit, a primary LCLC resonance compensation network, a cylindrical coupling mechanism, a secondary LCLC resonance compensation network, a three-phase rectifier circuit, and a buck circuit connected in sequence. The cylindrical coupling mechanism serves as the core of the system.

[0103] Embodiment 2

[0104] The electric-field-coupled wireless power transmission system of the present invention based on a three-phase cylindrical coupling mechanism has a structure as Figure 4 shown, which is composed of a DC input power supply, a three-phase inverter circuit, a primary LCLC resonance compensation network, a cylindrical coupling mechanism, a secondary LCLC resonance compensation network, a three-phase rectifier circuit, and a buck circuit connected in sequence. The cylindrical coupling mechanism serves as the core of the system.

[0105] Combined with Figure 1 , the specific structure of the cylindrical coupling mechanism is as follows: It includes a transmitting electrode plate and a receiving electrode plate. The transmitting electrode plate is composed of 3 arc-shaped metal plates. Specifically, the transmitting electrode plate includes transmitting electrode plate P1, transmitting electrode plate P2, and transmitting electrode plate P3. The receiving electrode plate is composed of 3 arc-shaped metal plates. The receiving electrode plate includes receiving electrode plate P4, receiving electrode plate P5, and receiving electrode plate P6. The receiving electrode plate is placed inside the transmitting electrode plate to form a cylindrical structure. Receiving electrode plate P4, receiving electrode plate P5, and receiving electrode plate P6 are installed on the inner wall of the intelligent robot shell, and transmitting electrode plate P1, transmitting electrode plate P2, and transmitting electrode plate P3 are installed on the wireless charging device.

[0106] Embodiment 3

[0107] The electric-field-coupled wireless power transmission system of the present invention based on a three-phase cylindrical coupling mechanism has a structure as Figure 4 shown, which is composed of a DC input power supply, a three-phase inverter circuit, a primary LCLC resonance compensation network, a cylindrical coupling mechanism, a secondary LCLC resonance compensation network, a three-phase rectifier circuit, and a buck circuit connected in sequence. The cylindrical coupling mechanism serves as the core of the system.

[0108] Combined with Figure 1, The specific structure of the cylindrical coupling mechanism is as follows: It includes a transmitting electrode plate and a receiving electrode plate. The transmitting electrode plate is composed of 3 arc-shaped metal plates. Specifically, the transmitting electrode plate includes transmitting electrode plate P1, transmitting electrode plate P2, and transmitting electrode plate P3. The receiving electrode plate is composed of 3 arc-shaped metal plates. The receiving electrode plate includes receiving electrode plate P4, receiving electrode plate P5, and receiving electrode plate P6. The receiving electrode plate is placed inside the transmitting electrode plate to form a cylindrical structure. Receiving electrode plate P4, receiving electrode plate P5, and receiving electrode plate P6 are installed on the inner wall of the intelligent robot housing, and transmitting electrode plate P1, transmitting electrode plate P2, and transmitting electrode plate P3 are installed on the wireless charging device.

[0109] Receiving electrode plate P4 is placed inside transmitting electrode plate P1, receiving electrode plate P5 is placed inside transmitting electrode plate P2, and receiving electrode plate P6 is placed inside transmitting electrode plate P3. The distance between the transmitting electrode plate and the receiving electrode plate is 0.5 cm to 1.5 cm. The optimal state is achieved when the distance is 1 cm.

[0110] The primary side LCLC resonance compensation network and the secondary side LCLC resonance compensation network have the same structure, both including six compensation inductors and six compensation capacitors. One end of the 3 compensation inductors L f1 、L f2 、L f3 are all connected to the bridge arm of the three-phase inverter circuit. The other ends of the 3 compensation inductors L f1 、L f2 、L f3 are all connected in parallel with compensation capacitors C f1 、C f2 、C f3 and are also connected to the first ends of the other 3 compensation inductors L 1 、L 2 、L 3 . The ends of compensation inductors L 1 、L 2 、L 3 are connected in parallel with compensation capacitors C p1 、C p2 、C p3 . The ends of compensation inductors L 1 、L 2 、L 3 are also respectively connected to the transmitting electrode plates P1, P2, and P3 of the cylindrical coupling mechanism correspondingly. The first ends of the first 3 compensation inductors L 4 、L 5 、L 6 of the secondary side LCLC resonance compensation network are respectively connected to the receiving electrode plates P4, P5, and P6 of the cylindrical coupling mechanism correspondingly. The first ends of the first 3 compensation inductors L 4 、L 5 、L 6 are also respectively connected to 3 compensation capacitors Cp4 and C p5 and C p6 are connected in parallel. The first three compensation inductors L 4 , L 5 , L 6 are respectively connected in parallel with the compensation capacitors C f1 , C f2 , C f3 and are connected in parallel with the last three compensation inductors L f4 , L f5 , L f6 at their first ends. The last three compensation inductors L f4 , L f5 , L f6 are respectively connected to the midpoints of the bridge arms of the three-phase rectifier circuit at their last ends. The secondary LCLC resonant compensation network is connected to the three-phase rectifier circuit, converts the transmitted alternating current into direct current, and then is connected to the buck circuit to transmit stable electric energy to the load.

[0111] The three-phase inverter circuit is a three-phase voltage source bridge inverter circuit, which is composed of six switching tubes. The switching tubes are divided into two groups, with three switching tubes in each group. The first group includes switching tubes Q 1 , switching tube Q 2 , switching tube Q 3 , and the second group includes switching tubes Q 4 , switching tube Q 5 , switching tube Q 6 , corresponding to three-phase outputs respectively. The three-phase outputs are also connected to the primary LCLC resonant compensation network. The DC input power supply is connected to the input end of the three-phase inverter circuit to convert the DC power generated by the power supply into high-frequency three-phase alternating current.

[0112] The present invention uses a high-frequency electric field as the energy transmission medium. The coupling mechanism of this technology is lightweight, low-cost, has good flexibility, does not generate eddy current losses in the surrounding conductors, and has good electromagnetic compatibility.

[0113] In this system, it is necessary to reasonably set the parameters of the primary and secondary compensation networks according to the built coupling mechanism so that the entire system has the same resonant state, and the energy transmission efficiency will be greatly improved. The LCLC compensation network is used to maintain the resonant conditions of the electric field coupling type wireless power transmission system, and a multiphase metal plate capacitive coupling structure based on a high-frequency alternating electric field is used to transmit power.

[0114] On the primary side, the DC voltage is inverted through a three-phase inverter. On the secondary side, a full-bridge circuit can be used to rectify the high-frequency AC voltage. The output voltage and current can be regulated through a controlled DC-DC converter for charging.

[0115] Embodiment 4

[0116] The electric field coupling type wireless power transmission system based on a three-phase cylindrical coupling mechanism has a structure as follows Figure 4 shown, which is composed of a DC input power supply, a three-phase inverter circuit, a primary side LCLC resonance compensation network, a cylindrical coupling mechanism, a secondary side LCLC resonance compensation network, a three-phase rectifier circuit, and a buck circuit connected in sequence. The cylindrical coupling mechanism is the core of the system.

[0117] Combined with Figure 1 , the specific structure of the cylindrical coupling mechanism is as follows: It includes a transmitting electrode plate and a receiving electrode plate. The transmitting electrode plate is composed of 3 arc-shaped metal plates. Specifically, the transmitting electrode plate includes transmitting electrode plate P1, transmitting electrode plate P2, and transmitting electrode plate P3. The receiving electrode plate is composed of 3 arc-shaped metal plates. The receiving electrode plate includes receiving electrode plate P4, receiving electrode plate P5, and receiving electrode plate P6. The receiving electrode plate is placed inside the transmitting electrode plate to form a cylindrical structure. Receiving electrode plates P4, P5, and P6 are installed on the inner wall of the intelligent robot housing, and transmitting electrode plates P1, P2, and P3 are installed on the wireless charging device.

[0118] Receiving electrode plate P4 is placed inside transmitting electrode plate P1, receiving electrode plate P5 is placed inside transmitting electrode plate P2, and receiving electrode plate P6 is placed inside transmitting electrode plate P3. The distance between the transmitting electrode plate and the receiving electrode plate is 0.5 cm to 1.5 cm. The best state is achieved when the distance is 1 cm.

[0119] The primary side LCLC resonance compensation network and the secondary side LCLC resonance compensation network have the same structure, both including six compensation inductors and six compensation capacitors. One end of the 3 compensation inductors L f1 , L f2 , L f3 of the primary side LCLC resonance compensation network is connected to the bridge arm of the three-phase inverter circuit. The other ends of the 3 compensation inductors L f1 , L f2 , L f3 are all connected in parallel with compensation capacitors C f1 , C f2 , C f3 , and are also connected to the first ends of the other 3 compensation inductors L 1 , L 2 , L 3 . The ends of compensation inductors L 1 , L 2 , L 3 are connected in parallel with compensation capacitors C p1 , C p2 , C p3 . The ends of compensation inductors L 1 , L 2 , L 3The ends are respectively and correspondingly connected to the transmitting plates P1, P2, and P3 of the cylindrical coupling mechanism, and the first three compensation inductors L of the secondary LCLC resonance compensation network 4 , L 5 , L 6 The first ends are respectively and correspondingly connected to the receiving plates P4, P5, and P6 of the cylindrical coupling mechanism, and the first three compensation inductors L 4 , L 5 , L 6 The first ends are also respectively connected in parallel with three compensation capacitors C p4 , C p5 , C p6 The first three compensation inductors L 4 , L 5 , L 6 The ends are respectively connected in parallel with the compensation capacitors C f1 , C f2 , C f3 and are connected to the first ends of the last three compensation inductors L f4 , L f5 , L f6 The first ends of the last three compensation inductors L f4 , L f5 , L f6 The ends are respectively and correspondingly connected to the midpoints of the bridge arms of the three-phase rectifier circuit. The secondary LCLC resonance compensation network is connected to the three-phase rectifier circuit, converts the transmitted alternating current into direct current, and then is connected to the buck circuit to transmit the stable electric energy to the load.

[0120] The three-phase inverter circuit is a three-phase voltage source bridge inverter circuit, which is composed of six switching tubes. The switching tubes are divided into two groups, each group has three switching tubes. The first group includes switching tube Q 1 , switching tube Q 2 , switching tube Q 3 , and the second group includes switching tube Q 4 , switching tube Q 5 , switching tube Q 6 , corresponding to three-phase outputs respectively. The three-phase outputs are also connected to the primary LCLC resonance compensation network. The DC input power supply is connected to the input end of the three-phase inverter circuit to convert the DC power emitted by the power supply into high-frequency three-phase alternating current.

[0121] The specific structure of the three-phase rectifier circuit is: it is composed of six switching tubes S 1 , S 2 , S 3 , S 4 , S 5 , S 6 and is divided into three groups corresponding to the three phases. Each group has two switching tubes, which are respectively the upper and lower bridge arms of the switching tubes of the three-phase full-bridge rectifier circuit. Among them, the switching tube S 1, switching transistor S 4 is a group, and switching transistor S 2 , switching transistor S 5 is a group, and switching transistor S 3 , switching transistor S 6 is a group. The compensation inductors of the secondary - side LCLC resonant compensation network are respectively connected to the mid - points of the three bridge arms of the rectifier circuit, and the output of the three - phase rectifier circuit is also connected to the buck circuit.

[0122] The core part of the system is its coupling mechanism, which consists of several metal plates. The arrangement of these plates and their interaction together determine the capacitance of the coupling capacitor, and thus affect the efficiency of the system for transmitting electrical energy. These capacitive coupling mechanisms with different shapes can be customized according to specific application requirements to ensure the maximum coupling area, thereby enhancing the efficiency of the coupling capacitor. To improve the overall performance of the system, the design focus should be placed on increasing the coupling area.

[0123] The system power supply is a DC power supply. The primary - side energy emission source is a three - phase high - frequency inverter circuit based on MOSFETs, the coupling mechanism is a cylindrical coupling mechanism (six arc - shaped metal plates), and the secondary - side is a three - phase full - bridge rectifier circuit based on MOSFETs. When the system works, the high - frequency inverter converts the DC power supply into high - frequency alternating current and supplies it to the resonant network. The high - frequency high - voltage current generated by the resonant network is transmitted to the cylindrical coupling mechanism to excite a high - frequency electric field. The receiving plates located in the high - frequency electric field induce displacement current, thereby realizing the propagation of energy. The full - bridge rectifier circuit on the secondary - side converts the output alternating current into direct current and supplies it to the load to generate voltage for output.

[0124] The multi - phase cylindrical coupling structure transfers electrical energy from the transmitting plate to the receiving plate through a high - frequency alternating electric field. This system breaks away from the constraints of traditional power - supply methods such as charging with metal wires or cables, which have relatively low flexibility and safety. Moreover, the system realizes stable electrical - energy transmission, thereby ensuring the safe and reliable operation of electrical equipment. It uses a high - frequency electric field as the energy - transmission medium. The coupling mechanism is lightweight, low - cost, has good flexibility, does not generate eddy - current losses in surrounding conductors, and has good electromagnetic compatibility.

[0125] Embodiment 5

[0126] The method for electric - field - coupled wireless power transmission based on a three - phase cylindrical coupling mechanism of the present invention is as follows:

[0127] The radius R of the main side - plates of the cylindrical coupling mechanism 1 is 300 mm, the radius R of the secondary side - plates 2 is 270 mm, the height h of the metal plates is 600 mm, and the central angle θ of the metal plates is 100°. For air as the medium, the dielectric constant determines the size of the coupling capacitor. The relationship between the dielectric constant, temperature, and the angular frequency of electromagnetic waves is as follows:

[0128]

[0129] In the formula:

[0130] ε ∞ (S, T) is the limit value of the dielectric constant at high frequencies;

[0131] ε 0 is the dielectric coefficient of free space;

[0132] f is the frequency of the electromagnetic wave;

[0133] ε S (S, T) is the static dielectric constant of air;

[0134] δ(S, T) is the ionic conductivity;

[0135] τ(S, T) is the Debye relaxation time.

[0136] The coupling capacitance C of the cylindrical coupling mechanism M is expressed as:

[0137]

[0138] In the formula:

[0139] ε 0 is the dielectric constant of the dielectric between the plates;

[0140] a is the semi-major axis of the elliptic cylinder formed by the curved panel;

[0141] b is the semi-minor axis of the elliptic cylinder formed by the curved panel;

[0142] c is the semi-focal length of the elliptic cylinder formed by the curved panel;

[0143] α is the central angle of the curved metal plate.

[0144] If the curved metal plate is converted into a symmetric cylindrical capacitor, where a = b and c = 0, then the coupling capacitor C M is expressed as:

[0145]

[0146] From the above analysis, it can be seen that the coupling capacitance value involved in the present invention is not only related to the dielectric constant of the dielectric between the plates, but also related to the central angle of the curved metal plate. It is different from the traditional coupling mechanism.

[0147] Example 6

[0148] The electric field coupling type wireless power transmission method based on the three-phase cylindrical coupling mechanism of the present invention is as follows:

[0149] The radius R of the main side plate of the cylindrical coupling mechanism 1 is 300 mm, and the radius R of the secondary side plate 2 is 270 mm. The height h of the metal plate is 600 mm, and the central angle θ of the metal plate is 100°. For the air medium, the magnitude of the dielectric constant determines the magnitude of the coupling capacitance. The relationship between the dielectric constant, temperature, and the angular frequency of the electromagnetic wave is as follows:

[0150]

[0151] In the formula:

[0152] ε ∞ (S,T) is the limit value of the dielectric constant at high frequencies;

[0153] ε 0 is the dielectric coefficient of free space;

[0154] f is the frequency of the electromagnetic wave;

[0155] ε S (S,T) is the static dielectric constant of air;

[0156] δ(S,T) is the ionic conductivity;

[0157] τ(S,T) is the Debye relaxation time.

[0158] The coupling capacitance C of the cylindrical coupling mechanism M is expressed as:

[0159]

[0160] In the formula:

[0161] ε 0 is the dielectric constant of the dielectric between the plates;

[0162] a is the semi-major axis of the elliptic cylinder formed by the curved plate;

[0163] b is the semi-minor axis of the elliptic cylinder formed by the curved plate;

[0164] c is the semi-focal length of the elliptic cylinder formed by the curved plate;

[0165] α is the central angle of the curved metal plate.

[0166] If the curved metal plate is converted into a symmetric cylindrical capacitor, where a = b and c = 0, then the coupling capacitor C M is expressed as:

[0167]

[0168] From the above analysis, it can be seen that the coupling capacitance value involved in the present invention is not only related to the dielectric constant of the dielectric between the plates, but also to the central angle of the curved metal plate, which is different from the traditional coupling mechanism.

[0169] As shown in Figure 2(a) and Figure 2(b), the coupling capacitance value changes when the coupling plates are offset, where Figure 2(a) shows the change of coupling capacitance when the coupling plates rotate, and Figure 2(b) shows the change of coupling capacitance when the coupling plates are vertically offset. When the relative position of the plates is offset, the coupling capacitance decreases. When the rotation angle is 10 degrees, the coupling capacitance decreases from 143pf to 133pf, when the rotation angle is 20 degrees, it decreases to 121pf, and when the rotation angle is 60 degrees, it decreases to 61pf; when the vertical offset distance is 5cm, the coupling capacitance decreases from 143pf to 138pf, when 10cm, it decreases to 126pf, and when 30cm, it decreases to 81pf.

[0170] like Figure 3 As shown, the circuit topology and coupling mechanism of the electric field coupling power transmission system involved in the present invention are three-phase symmetrical, which means that the circuit structure and interaction mode of the three phases are the same. Therefore, when analyzing, the three-phase system can be simplified into a single-phase system, and the circuit can be further simplified into a π-type network. Such network simplification helps to more clearly understand the power transmission mechanism of the system, thereby performing more effective performance analysis and design optimization. The details are as follows:

[0171] The input and output voltage of phase A is defined as V 1 and V 2 , the input and output current is defined as I 1 and I 2 , considering the coupling mechanism as a two-port network, the input-output relationship is as follows:

[0172]

[0173] The input-output relationship of the π-type circuit model is also expressed as:

[0174]

[0175] By combining equations (4) and (5), the equivalent coupling capacitance parameters are obtained:

[0176]

[0177] Therefore, the equivalent input capacitor C at the receiver and transmitter in.Tx and C in.Rx It is expressed as:

[0178]

[0179] The relationship between the parameters of the resonant network is expressed as:

[0180]

[0181] Finally, the measured capacitance values between each pair of electrodes are substituted into the formula to obtain the value of the compensation inductor, completing the design of the compensation network.

[0182] As Figure 4 shown, in the electric field coupling type wireless power transmission circuit involved in the present invention, the DC power supply is converted into high-frequency three-phase alternating current after passing through the full-bridge inverter network. The three-phase voltage source bridge inverter circuit is composed of six switching tubes, divided into two groups, with three switching tubes in each group, corresponding to the three-phase outputs respectively.

[0183] The present invention is particularly applicable to devices such as intelligent robots. The system consists of a DC input power supply, a three-phase inverter circuit, an LCLC resonant compensation network, a cylindrical coupling mechanism, a three-phase rectifier circuit, and a buck circuit. Its core lies in providing a new type of coupling mechanism, aiming to achieve efficient electric field coupling type wireless power transmission and significantly improve the anti-offset ability under rotational misalignment conditions. To verify the effectiveness of this cylindrical coupling mechanism, the present invention establishes a detailed system model to study its power transmission performance. Through modeling analysis, the topological structure of the electric field coupling type wireless power transmission system is further established. Specifically, on the primary side, the DC power supply is first converted into high-frequency alternating current through a three-phase high-frequency inverter circuit. This high-frequency inverter is responsible for converting direct current into high-frequency alternating current suitable for use in the resonant network. Subsequently, these high-frequency alternating currents are transmitted to the LCLC resonant network, generating high-frequency high-voltage currents, which in turn excite the high-frequency electric field within the cylindrical coupling mechanism to complete wireless energy transmission. On the secondary side, a full-bridge rectifier circuit converts the received high-frequency alternating current into stable direct current to ensure that a constant charging voltage can be provided for the load. At this time, both the transmitting end (primary side) and the receiving end (secondary side) of the system are in a resonant state, which not only optimizes the energy transmission path but also greatly improves the energy transmission efficiency.

Claims

1. An electric field coupling wireless power transmission system based on a three-phase columnar coupling mechanism, characterized in that: It is composed of a DC input power supply, a three-phase inverter circuit, a primary LCLC resonant compensation network, a columnar coupling mechanism, a secondary LCLC resonant compensation network, a three-phase rectifier circuit and a buck circuit, which are connected in sequence, and the columnar coupling mechanism is the core of the system.

2. The electric field coupling type wireless power transmission system based on the three-phase column coupling mechanism according to claim 1 is characterized in that: The specific structure of the columnar coupling mechanism is as follows: it includes an emitting plate and a receiving plate, the emitting plate is composed of three arc-shaped metal plates, specifically, the emitting plate includes an emitting plate P1, an emitting plate P2, and an emitting plate P3, the receiving plate is composed of three arc-shaped metal plates, the receiving plate includes a receiving plate P4, a receiving plate P5, and a receiving plate P6, the receiving plate is placed on the inner side of the emitting plate to form a columnar structure, the receiving plates P4, P5, and P6 are installed on the inner wall of the intelligent robot shell, and the emitting plates P1, P2, and P3 are installed on the wireless charging device.

3. The electric field coupling type wireless power transmission system based on the three-phase column coupling mechanism according to claim 2 is characterized in that: The receiving plate P4 is placed inside the emitting plate P1, the receiving plate P5 is placed inside the emitting plate P2, the receiving plate P6 is placed inside the emitting plate P3, and the distance between the emitting plate and the receiving plate is 0.5 cm to 1.5 cm.

4. The electric field coupling type wireless power transmission system based on the three-phase column coupling mechanism according to claim 3 is characterized in that: The primary LCLC resonant compensation network has the same structure as the secondary LCLC resonant compensation network, both of which include six compensation inductors and six compensation capacitors. f1 , L f2 , L f3 One end of each of the three compensation inductors L is connected to the bridge arm of the three-phase inverter circuit. f1 , L f2 , L f3 The other end is connected to the compensation capacitor C f1 , C f2 , C f3 In parallel, it is also connected to the other three compensation inductors L1, L2, L3, and the ends of the compensation inductors L1, L2, L3 are connected to the compensation capacitor C p1 , C p2 , C p3 The ends of the compensation inductors L1, L2, and L3 are connected in parallel to the emitter plates P1, P2, and P3 of the tubular coupling mechanism respectively. The first three compensation inductors L4, L5, and L6 of the secondary side LCLC resonant compensation network are connected to the receiving plates P4, P5, and P6 of the tubular coupling mechanism respectively. The first three compensation inductors L4, L5, and L6 are also connected to the three compensation capacitors C p4 , C p5 , C p6 The first three compensation inductors L4, L5, and L6 are connected in parallel to the compensation capacitors C f1 , C f2 , C f3 Connect in parallel with the last three compensation inductors L f4 , L f5 , L f6 The first end is connected, and the last three compensation inductors L f4 , L f5 , L f6 The ends are respectively connected to the middle points of the bridge arms of the three-phase rectifier circuit.

5. The electric field coupling type wireless power transmission system based on the three-phase column coupling mechanism according to claim 4 is characterized in that: The three-phase inverter circuit is a three-phase voltage-type bridge inverter circuit, which is composed of six switching tubes. The switching tubes are divided into two groups, each group has three switching tubes. The first group includes switching tubes Q1, Q2, and Q3, and the second group includes switching tubes Q4, Q5, and Q6, which correspond to three-phase outputs respectively. The three-phase output is connected to the primary-primary LCLC resonant compensation network. The DC input power supply is connected to the input end of the three-phase inverter circuit to convert the DC power emitted by the power supply into high-frequency three-phase AC power.

6. The electric field coupling type wireless power transmission system based on the three-phase column coupling mechanism according to claim 3 is characterized in that: The specific structure of the three-phase rectifier circuit is as follows: it is composed of six switch tubes S1, S2, S3, S4, S5, and S6, which are divided into three groups corresponding to the three phases. Each group has two switch tubes, which are the upper and lower bridge arms of the switch tube of the three-phase full-bridge rectifier circuit, respectively. The switch tube S1 and the switch tube S4 are a group, the switch tube S2 and the switch tube S5 are a group, and the switch tube S3 and the switch tube S6 are a group. The compensation inductance of the secondary side LCLC resonant compensation network is respectively connected to the midpoints of the three bridge arms of the rectifier circuit, and the output of the three-phase rectifier circuit is connected to the step-down circuit.

7. The electric field coupling type wireless power transmission system based on the three-phase column coupling mechanism according to claim 3 is characterized in that: The step-down circuit is a DC-DC converter.

8. An electric field coupling type wireless power transmission method based on a three-phase columnar coupling mechanism, based on the electric field coupling type wireless power transmission system based on the three-phase columnar coupling mechanism, specifically as follows: The radius R1 of the main side plate of the cylindrical coupling mechanism is 300 mm, the radius R2 of the secondary side plate is 270 mm, the height h of the metal plate is 600 mm, the center angle θ of the metal plate is 100°, and the relationship between the dielectric constant, temperature and the angular frequency of the electromagnetic wave is as follows: Where: ε ∞ (S,T) is the limiting value of the dielectric constant at high frequency; ε0 is the dielectric constant of free space; f is the frequency of the electromagnetic wave; ε S (S,T) is the static dielectric constant of air; δ(S,T) is the ionic conductivity; τ(S,T) is the Debye relaxation time.

9. The electric field coupling type wireless power transmission method based on the three-phase column coupling mechanism according to claim 8 is characterized in that: The coupling capacitance C of the cylindrical coupling mechanism M It is expressed as: Where: ε0 is the dielectric constant of the inter-plate dielectric; a is the semi-major axis of the elliptical cylinder formed by the curved plate; b is the semi-minor axis of the elliptical cylinder formed by the curved plate; c is the semi-focal length of the elliptical cylinder formed by the curved plate; α is the central angle of the curved metal plate; If the bent metal plate is transformed into a symmetrical cylindrical capacitor with a = b and c = 0, then the coupling capacitor C M It is expressed as: When the relative positions of the plates shift, the coupling capacitance decreases.

10. The electric field coupling type wireless power transmission method based on the three-phase column coupling mechanism according to claim 9 is characterized in that: Simplify the three-phase system into a single-phase system, and further simplify the circuit into a π-type network, as follows: The input and output voltages of phase A are defined as V1 and V2, and the input and output currents are defined as I1 and I2. The coupling mechanism is considered as a two-port network, and the input-output relationship is as follows: The input-output relationship of the π-type circuit model is also expressed as: By combining equations (4) and (5), the equivalent coupling capacitance parameters are obtained: Therefore, the equivalent input capacitor C at the receiver and transmitter in.Tx and C in.Rx It is expressed as: The relationship between the resonant network parameters is expressed as: Finally, the measured capacitance values ​​between the plates are substituted into the formula to obtain the compensation inductance value, thus completing the design of the compensation network. By controlling the on and off of six switching tubes composed of metal oxide semiconductor field effect transistors, different phase voltage outputs are obtained. When the control signal indicates that a certain switching tube is turned on, the corresponding drive circuit applies a positive voltage to the gate of the switching tube. This positive voltage forms a conductive channel between the gate and the source, allowing current to flow from the drain to the source.

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