Adjustable asynchronous motor

Abstract

The adjustable asynchronous motor is called KTD. It is the rotor of the traditional asynchronous motor which is transformed as follows: the rotor winding and its supporting facilities are cancelled, the rotor laminations and the squirrel cage bars are transformed as follows: first, select the better material of the lamination, divide the lamination into two groups of AB according to the odd and even number, and strengthen the insulation between the two groups of lamination, the lamination and the shaft, the lamination and the rotor squirrel cage bars, connect all the odd lamination with A connecting conductor to form the A pole of the capacitor, connect all the even lamination with B connecting conductor to form the B pole of the capacitor, the A and B connecting conductors are respectively insulated and fixed on the end pieces at both ends of the rotor, which form the A and B poles of the capacitor, and insert the isolation plate G made of low permeability material between the 2-3, 4-5… laminations to block the reverse capacitor current therebetween, only the 1-2, 3-4… laminations can flow the forward capacitor current; we call the rotor after such transformation as the rotor capacitor. The remote control switch installed at the end of the squirrel cage bar can control the on-off of the copper squirrel cage bar, so that the KTD can have two qualities of capacitive and neutral adjustable, the mechanical characteristics of the two qualities have no unstable section, and the KTD is a new type of asynchronous motor with simple structure and adjustable performance.

Description

(I) Technical Field:

[0001] This invention, "Adjustable Asynchronous Motor" (KTD for short), is a new type of asynchronous motor with simple structure and excellent performance. KTD uses a remote control switch to control the number of conducting squirrel cage bars in the rotor to continuously change the cosα value of the rotor capacitor, and can continuously switch between capacitive asynchronous motor RDJ and neutral asynchronous motor ZDJ in real time, realizing the adjustment and speed regulation functions of KTD. (II) Background Technology:

[0002] Existing squirrel-cage and wound-rotor induction motors only have inductive types and lack capacitive and neutral types. Due to the mechanical characteristics of inductive induction motors, a maximum electromagnetic torque can occur. When the speed decreases beyond the speed corresponding to this maximum value, the motor's mechanical characteristics... Figure 3 The M-curve in the figure will enter the unstable region, affecting its full effectiveness. (III) Summary of the Invention:

[0003] The KTD rotor is constructed as follows: Figure 1 As shown, this method eliminates the traditional asynchronous motor rotor windings and their associated facilities. The rotor laminations and squirrel cage bars are modified as follows: all odd-numbered laminations (1st, 3rd, etc.) are connected by conductor A to form the A pole of a capacitor, and all even-numbered laminations (2nd, 4th, etc.) are connected by conductor B to form the B pole of a capacitor. This ensures that the A and B poles are insulated from each other, forming a capacitor. Since the A and B laminations are arranged in a staggered pattern, and the inter-pole capacitances of AB and BA are approximately equal, after cutting the magnetic field lines of the stator, two equal-sized, opposite-direction capacitive current components will be formed between AB and BA, causing their electromagnetic torques to cancel each other out and weakening the motor's power. Therefore, the squirrel cage bars of the KTD are all made of copper and located at the rotor edge, forming the inductive part of the KTD; while the steel AB connecting conductors are located on the inner circumference, away from the edge of the laminations. Between the AB electrodes, a high dielectric constant material, such as epoxy phenolic silicon steel sheet varnish 9162 (ε≥50), is applied, forming a small capacitor. The BA electrodes are not coated; instead, a separator G made of a low dielectric constant material, such as polystyrene (ε=2.4~2.6), is inserted between them. The separator G separates the BA electrodes of each small capacitor with an air gap (ε=1), forming the capacitive part of the KTD. The inductive and capacitive parts combine to form the rotor capacitor, which significantly weakens the reverse current in the BA direction passing through the air gap of the separator and significantly increases the forward current in the AB direction, thus significantly enhancing the electromagnetic torque of the KTD. Under the induction of the stator's rotating magnetic field, the electromagnetic torque generated in the rotor capacitor causes the rotor to rotate.

[0004] In the KTD, one end of each squirrel cage bar is directly fastened to its end plate with screws to achieve electrical connection, while the other end of the squirrel cage bar is fastened to its end piece with insulating gaskets. A remote control switch is also installed to connect the squirrel cage bar to the end piece, allowing the remote switch to control the on / off state of the squirrel cage bar's circuit. This allows each squirrel cage bar to be individually controlled by its own remote switch. The switching on and off of different numbers of squirrel cage bars results in different inductive circuit strengths in the KTD rotor circuit. Combined with the capacitive portion of the rotor capacitor, this results in different cosα values, thus achieving the RDJ and ZDJ speed regulation and performance diversity. The fixing of the squirrel cage bars to the end pieces also secures the rotor; however, the AB connecting conductors are fastened to the end pieces at both ends of the rotor with insulating gaskets, blocking the flow of inductive current in the connecting conductors. These both compress the rotor laminations and connect the small capacitors in parallel, enhancing the rotor's capacitive properties.

[0005] When all the squirrel cage bars in the KTD are disconnected using a remote control switch to completely cut off the flow of inductive current, the rotor becomes a pure capacitive rotor, giving the RDJ a leading power factor. Increasing the number of AB laminations increases the capacitance of the RDJ rotor. In the RDJ, as the rotor speed increases, the slip of the rotor circuit decreases, causing the frequency of the induced electromotive force (EMF) in the rotor circuit to increase while the amplitude gradually decreases. This leads to a decrease in capacitive reactance and an increase in capacitive current. The result of the compensation between the decrease in induced EMF and the increase in capacitive current is that the electromagnetic torque of the RDJ will decrease slightly as the slip decreases. Therefore, the mechanical characteristics of the RDJ are slightly stiff, somewhat similar to a DC shunt motor. When the speed reaches the ideal no-load speed n0, the slip is 0, the rotor induced EMF is 0, and the rotor current and its electromagnetic torque are also 0, causing the mechanical characteristics to intersect at the longitudinal axis. At low speeds, the RDJ has a very large starting torque.

[0006] While delivering mechanical energy to users, RDJ can also supply capacitive current to the power grid, thereby improving the power factor of the grid and achieving energy savings.

[0007] When ZDJ operates at high speeds close to n0, due to the small slip, the frequency of the induced electromotive force on the rotor is very low. At this point, the capacitive reactance of the rotor capacitor is relatively large, causing […]. Figure 2The current flowing through the rotor capacitor branch is almost zero, while the inductive reactance in the rotor squirrel cage branch is relatively small. Therefore, the rotor circuit is essentially resistive at this time, and the power factor of the rotor circuit is cosα≈1. Thus, the upper mechanical characteristics of the ZDJ are relatively stiff and similar to those of a DC shunt motor. However, when the ZDJ speed decreases to a certain speed, the increase in the frequency of the induced electromotive force in the rotor circuit makes the decrease in the capacitive reactance of the capacitor branch insufficient to fully compensate for the increase in the inductive reactance in the rotor inductive branch. This causes the power factor of the rotor circuit to gradually lag. Through the mutual compensation of the capacitor branch and the squirrel cage branch, a downward segment of the mechanical characteristics is formed, where the rotor current I2 synthesized with the increase of slip and the electromagnetic torque of the ZDJ can only increase slowly but can still operate stably. This makes the mechanical characteristics of the ZDJ similar to those of an excavator, as shown in […]. Figure 3 As shown in the figure. Because the KTD is compensated by the capacitive current of the rotor capacitor throughout the entire operating range, its power factor is always higher than that of the corresponding conventional asynchronous motor. Therefore, the efficiency of the KTD is also higher than that of the conventional asynchronous motor, and the KTD cannot have unstable characteristics. (iv) Description of the attached drawings:

[0008] The accompanying drawings of this invention will be described in detail below:

[0009] [ Figure 1This describes the structural principle of KTD's rotor capacitor. The A-connecting conductor in the rotor is not connected to the B-pole lamination, and similarly, the B-connecting conductor is not connected to the A-pole lamination. There is an isolation plate G between the BA laminations, so that each group of AB laminations is isolated by the G plates on both sides, forming individual small capacitors. Because the AB laminations are positioned at different points along the stator magnetic field axis, they will generate different potentials under the influence of the rotating magnetic field, resulting in corresponding capacitance voltage and capacitance current. The isolation plate G, made of a low-permeability material, blocks the reverse capacitance current between the BA laminations, allowing only the forward capacitance current to flow between the AB laminations. The squirrel cage bars are located at the edges of the laminations. One end of each squirrel cage bar is fastened (or welded) to its end plate with screws and electrically connected. The other end of the squirrel cage bar is fastened to its end plate with screws via insulating gaskets, but a remote control switch electrically connects this end of the squirrel cage bar to its end plate and controls its on / off state. The AB connecting conductors are evenly distributed on the circumference away from the edge of the laminations, preventing them from cutting magnetic lines of force in the high-density magnetic field of the stator like the squirrel cage bars. This forms a rotor capacitor. If the remote control switch is turned off, blocking the inductive current from flowing through all the squirrel cage bars, only the capacitive current can flow between the AB laminations. In this case, KTD becomes a purely capacitive RDJ. If the squirrel cage bars are energized, they can form the inductive component in the KTD rotor. If the remote control switch is continuously and evenly controlled to continuously and evenly switch the squirrel cage bars on and off, the cosα value of the rotor capacitor can be continuously and evenly changed, thus achieving the performance diversity of RDJ and ZDJ and the ability to continuously and evenly adjust the speed.

[0010] [ Figure 2 [This is the T-type equivalent circuit diagram of KTD. For ZDJ, it is in [...] Figure 2 There are two branches in the circuit, one with a capacitor and the other with an inductor connected in parallel, where X... C2′ It is the capacitive reactance of the rotor capacitor, X L2′ It is the rotor's inductive reactance. However, for a purely capacitive RDJ, since none of the squirrel cage bars can carry inductive current, therefore... Figure 2 The inductive branch represented by the dashed line in the diagram is blocked, and only the capacitive reactance X exists. C2′ A side road.

[0011] [ Figure 3 [These are the characteristic curves of traditional induction asynchronous motors and RDJ, ZDJ motors.] At the ideal no-load speed n, the ZDJ motor has a large capacitive reactance and a small impedance in the rotor circuit, with cosα ≈ 1, resulting in a relatively stiff characteristic. As the speed decreases, a capacitive current I is generated in the rotor, which increases with the decrease in speed. 2C′ It is related to the gradually decreasing inductance current (I) in the rotor winding. 2L′The synthesis of the induced electromotive force (EMF) will generate a rotor current I2, and I2 increases substantially with increasing slip, causing ZDJ to decrease along a characteristic similar to that of a DC shunt motor. As the slip continues to increase, the rotor inductive reactance increases significantly due to the further increase in the frequency of the induced EMF in the rotor, leading to a decrease in I... 2L， The significant reduction in I2 softens and lowers the mechanical characteristics of the ZDJ, making its overall mechanical characteristics similar to those of an excavator. However, because the ZDJ has an additional rotor capacitor that provides a larger capacitive current as the speed decreases, it compensates for this current and thus avoids the unstable characteristic segment of an induction motor. However, if excessive squirrel cage bars are added to the rotor, when all bars are conducting, the inductive portion of the ZDJ rotor may become significantly larger than the capacitive portion. This causes the rotor capacitor's capacitive current to only compensate for the drooping segment of the ZDJ's mechanical characteristics, keeping the drooping segment of its excavator characteristic parallel to the longitudinal axis. In this drooping segment, the corresponding electromagnetic torque remains constant as the speed decreases. For clarity, this drooping segment parallel to the longitudinal axis can be called the critical characteristic of the ZDJ's excavator characteristic. If the number of conducting squirrel cage bars is further increased, the corresponding drooping segment will shift to the left, exceeding the critical characteristic, resulting in the characteristics of an induction motor with an unstable drooping segment. Therefore, in the design of KTD, to avoid unstable performance of the inductive asynchronous motor, the number of squirrel cage bars must be limited, but the number of laminations can be set as high as possible. At the ideal no-load speed n0, the slip of RDJ is 0, cosα≈0, making both rotor current and electromagnetic torque zero, so its mechanical characteristic will intersect the longitudinal axis at this time. When the speed decreases from n0 due to increased load, the slip increases, causing the amplitude and frequency of the induced electromotive force in the rotor to increase, thus increasing the X in the rotor. C2′ with I 2C′ Both gradually increase. As the rotor's cosα increases, the characteristics gradually soften, and the electromagnetic torque increases accordingly, making the mechanical characteristics of the RDJ similar to those of a DC shunt motor. When the load increases and the speed continues to decrease, the RDJ will decrease along its mechanical characteristics, but the stiffness of the characteristics will not change significantly.

[0012] [ Figure 4This is a design drawing of KTD's rotor laminations. The shaft hole is hexagonal. The six connecting conductor holes in laminations A and B are of two types: through holes (large holes) and engagement holes (small holes). The engagement holes have six teeth; the outer diameter of the teeth is smaller than the diameter of the through hole, and the inner diameter of the teeth is slightly smaller than the outer diameter of the connecting conductor. The small holes ensure that the laminations can achieve electrical connection with their corresponding connecting conductors. The small and large holes of lamination A correspond to the large and small holes of lamination B. When using a steel hexagonal rotor shaft, the shaft and laminations are isolated by a high-strength insulating pad. The six small notches in laminations A and B should be in different positions; these notches are used after rotor assembly to check whether the cross-stacking of laminations A and B is uniform and correct.

[0013] [ Figure 5 [This refers to the design of KTD's isolation plate G. In actual installation, if the ribs of the isolation plate overlap with the spiral ventilation holes on the rotor, the overlapping ribs can be cut off to ensure the ventilation holes are unobstructed.] (V) Specific Implementation Methods:

[0014] In the design, the electrical properties, mechanical strength, and heat dissipation capacity of the materials used should be given priority consideration. For example, selecting rotor laminations, isolation plates [G], and steel end plates of appropriate thickness and characteristics, as well as selecting an appropriate number of copper squirrel cage bars and steel connecting conductors, can achieve better electrical performance and increase the mechanical strength of the rotor. The isolation plate G is made of materials with low dielectric constant and heat resistance, such as polytetrafluoroethylene propylene, rubber, polystyrene, and polyvinyl chloride. The rotor's A and B laminations, connecting conductors, and squirrel cage bars are all pickled to remove burrs before assembly.

[0015] A person (Mr. Wu from Shantou) once made a prototype for the predecessor of KTD, the "Capacitor Rotor Asynchronous Motor," which did not yet have an isolation plate G. His prototype truly realized a rotor capacitor with an advanced power factor. He also tested the parameters of the prototype: "The motor is 0.75KW, and the stator current is 1.2A at 50HZ and 130 rpm. The capacitance of the rotor capacitor is 0.04μF, and the speed range can reach 200-1000r / min." Although the electromagnetic torque of the prototype was still very small, the practical application of the prototype proved that it basically met the scientific requirements of innovation. My analysis shows that the prototype's torque is very small because its lamination arrangement is improper: the original prototype arranged each positive and negative lamination directly in a cross pattern, and the distance between each positive lamination and the negative laminations on both sides was equal, making the capacitance between the lattice terminals on both sides basically equal. Therefore, when cutting the magnetic field lines of the stator magnetic field, the positive laminations will generate two current components in opposite directions to the negative laminations on both sides, and their effects will cancel each other out, thus significantly weakening the electromagnetic torque of the original prototype. This paper has already described the modification of the rotor capacitor in the KTD. A high dielectric constant material, such as epoxy phenolic silicone steel sheet paint 9162 (ε≥50), is applied between the AB poles, forming a small capacitor. However, no coating is applied between the BA poles; instead, a separator made of a low dielectric constant material, such as polystyrene (ε=2.4~2.6), is inserted. The separator uses an air gap (ε=1) to separate the BA poles. This significantly reduces the reverse current in the BA direction passing through the air gap while significantly enhancing the forward current in the AB direction. This greatly enhances the electromagnetic torque of the KTD and allows for real-time adjustment of the remote control switch, enabling the KTD to be converted into various RDJ or ZDJ configurations. This constitutes a high-performance KTD.

[0016] As a high-performance new product, KTD's advanced principles guarantee superior performance and low cost. Furthermore, the prototype of its predecessor, the "Capacitor Rotor Asynchronous Motor," validates KTD's scientific validity and feasibility. However, KTD is still an innovation, and many of its specific technical specifications require testing after the equipment is finalized. For example, configuring the squirrel cage bars and laminations for different drive systems, and determining the appropriate remote control switch programs for various operating conditions, all require optimization through repeated practice. This aligns with the general process of innovation towards success and reflects the necessary cognitive process of understanding a new technology. After repeated practice and refinement, KTD will undoubtedly become a highly effective and practical product.

[0017] Key characteristics of KTD include:

[0018] ① The ratio of capacitive to inductive components in the rotor capacitor can be changed by controlling the on / off state of the squirrel cage bars with a remote control switch, allowing KTD to obtain RDJ and ZDJ with different performance and speed. Because RDJ has mechanical characteristics similar to a DC shunt motor, it has a large electromagnetic torque and good running stability at low speeds. During startup, the remote control switch can temporarily switch RDJ to ZDJ to limit the impact of starting current and achieve soft start and continuous and precise speed regulation. RDJ simplifies the starting and speed regulation device and saves energy. It can switch between RDJ and ZDJ instantaneously, which provides a very flexible operating condition. The static and dynamic response quality of RDJ is greatly optimized, making it very suitable as a power source for electric vehicles and other transportation vehicles.

[0019] ②The ZDJ exhibits stall characteristics, making it suitable as a drive unit for heavy machinery with impact loads, such as excavators and rolling mills. Because the ZDJ lacks the commutator and brushes of a DC motor, it avoids commutator arcing even under strong load impacts. Furthermore, it allows for easy switching and speed adjustment between the RDJ and ZDJ models to adapt to different operating conditions, resulting in more flexible operation. This gives the ZDJ greater controllability, impact resistance, and lower equipment and maintenance costs compared to a DC motor.

[0020] ③ Since RDJ can provide capacitive current to the power grid while outputting mechanical energy, and output mechanical energy while improving the power factor of the power grid, its function is equivalent to the resistance inserted in series in the compensation capacitor of the power grid (while RDJ converts electrical energy into mechanical energy and does useful work, the resistance inserted in series in the compensation capacitor can only convert electrical energy into heat energy and consume it for nothing, so RDJ shows the advantage of energy saving). It can play a stabilizing role in suppressing voltage fluctuations in the power grid. Therefore, RDJ has a higher cost performance than the compensation capacitor in the power grid.

[0021] ④ The KTD capacitor rotor has a simple yet robust structure. It is made of laminated laminations, isolation plates, connecting conductors, and squirrel cage bars, all stacked and tightly bound together. It is as solid as a lump of iron, possessing extremely strong mechanical shock resistance and capable of withstanding higher speeds and accelerations. Since the same capacitor rotor can be used with AC motor stators of essentially the same rated current but different models to form corresponding KTDs, the capacitor rotor demonstrates excellent versatility. This significantly reduces the hassle and investment required in the production, design, inventory, and management of KTDs, opening up a broad application market for them.

[0022] ⑤ The KTD capacitor rotor has a simple structure and strong adaptability. Therefore, it is possible to consider manufacturing a KTD ceramic rotor by imitating the manufacturing process of ceramic capacitors. This is a huge advancement that is unimaginable and impossible to achieve for general motor rotors. In this way, it is possible to obtain a higher quality KTD rotor with a cost-effectiveness far exceeding that of other types of motor rotors. Once successful, the waterproof, impact-resistant, maintenance-free, lightweight, and more versatile low-cost ceramic rotor will enable KTD to gain an unprecedentedly large market.

[0023] ⑥KTD's capacitor rotor structure is simple, so a spiral ventilation hole with open ends that rotates around the shaft can be added to its space. When the rotor rotates, it can automatically draw air into the hole, which will greatly improve the rotor's ventilation and cooling, reduce the rotor's rotational inertia and improve its dynamic response quality. This will enable KTD to obtain overload performance and dynamic quality that are far superior to other types of motors.

[0024] ⑦ Each squirrel cage bar of the KTD is connected to one end plate of the rotor with a remote control switch or inductive switch (different types of inductive switches with different induction sources can be used to control different numbers of squirrel cage bars) to control the on / off state of the squirrel cage bar circuit. This allows for real-time controllability of the cosine stability (COSA) in the KTD rotor circuit, enabling the KTD to transform into various RDJ or ZDJ motors with different performance characteristics in real time. This provides real-time and diverse performance control for RDJ and ZDJ motors. It is evident that the KTD has pioneered a new level of technology for real-time adjustable speed regulation of AC motors, improving dynamic quality and overload capacity. Clearly, the KTD's cost-effectiveness far surpasses that of traditional asynchronous motors. The KTD can completely dominate the asynchronous motor market and even partially seize the market share of synchronous motors and DC motors, becoming the king of rotating motors. It is evident that the significant innovation of the KTD has enormous market potential and excellent development prospects, with extremely significant technological, economic, and social benefits.

Claims

1. Adjustable asynchronous motor, abbreviated as KTD, is characterized by: KTD is a novel asynchronous motor with a simple structure and excellent performance. KTD uses a remote control switch to continuously control the number of conducting squirrel cage bars in the rotor capacitor, thereby continuously changing the cosα value of the rotor capacitor. It can then continuously switch its performance between a capacitive asynchronous motor (RDJ) and a neutral asynchronous motor (ZDJ) in real time, realizing the tuning and speed control functions of KTD. KTD eliminates the traditional asynchronous motor rotor winding and its supporting facilities, modifying the rotor laminations and squirrel cage bars as follows: the squirrel cage bars are all made of copper and located at the rotor edge, and the laminations are divided into an odd number. The [A] and even-numbered [B] groups are mutually insulated. The laminations of the [A] and [B] groups are electrically connected by corresponding [A] and [B] steel connecting conductors, each serving as one pole of a capacitor. The [A] and [B] connecting conductors are fixed to the end plates at both ends of the rotor via insulating pads. The [A] and [B] laminations are coated with a high dielectric constant dielectric material with appropriate heat resistance to improve capacitance and reduce dielectric loss; while the [B] and [A] laminations are not coated with dielectric material, but only a spacer plate [G] with an air gap, made of a material with a low dielectric constant, is inserted. The air gap can block the reverse capacitive current between [B] and [A], while increasing the forward capacitive current between [A] and [B] and the electromagnetic torque of KTD; thus, all the squirrel cage bars, the remote control switch, and the two sets of laminations [A] and [B] isolated by [G] and their connecting conductors together form the rotor capacitor; under the induction of the stator rotating magnetic field, a current will be induced in the rotor capacitor, generating an electromagnetic torque to make the rotor rotate; the squirrel cage bars are insulated from the laminations of [A] and [B] and the end plate at one end, but the squirrel cage bar at that end is connected to the end plate at that end through a remote control switch to control The circuit controls the switching of the inductor current, while the other end of the squirrel cage bar is fastened to its end plate by a nut and electrically connected. These squirrel cage bars are controlled by a remote control switch to conduct different numbers of squirrel cage bars, thereby generating different amounts of inductive components in the rotor. The combination of this with the capacitive components in the rotor capacitor can obtain different cosα values ​​of the rotor capacitor, thus achieving the diversity of RDJ and ZDJ performance. Due to the compensation of the capacitive current of the rotor capacitor, the power factor of the KTD is always higher than that of the traditional asynchronous motor, so its efficiency is always higher than that of the traditional asynchronous motor.

2. The RDJ according to claim 1 is characterized in that: If all remote control switches in KTD are turned off, preventing inductive current from flowing through any of the squirrel cage bars, the inductive portion of the rotor in RDJ becomes 0, while the capacitive portion reaches its maximum and cosα≈0. RDJ will resemble a purely capacitive rotor, and its mechanical characteristics will resemble a DC shunt motor, but at this point, the characteristics will be the stiffest. As the inductive portion of the rotor and cosα gradually increase, the characteristics will gradually soften. Generally, when the RDJ speed is at the ideal no-load speed, the slip is 0, and the rotor induced electromotive force, rotor current, and electromagnetic torque are all 0, causing the mechanical characteristics of RDJ to intersect at the longitudinal axis. As the slip increases from... As the speed gradually increases from zero, the amplitude of the induced electromotive force in the rotor circuit gradually increases while the capacitive reactance gradually decreases, causing the capacitive current and electromagnetic torque to gradually increase. At low speeds, the current of the RDJ is quite large. To limit the impact of the starting current, the number of conducting squirrel cage bars can be controlled by a remote control switch to temporarily switch the RDJ to a ZDJ for starting. The RDJ has excellent static and dynamic response quality, enabling soft starting, precise speed regulation, simplified starting and speed regulation devices, and energy saving. While outputting mechanical energy to the load, the RDJ can also output capacitive current to the power grid, thereby compensating for the power factor of the power grid and improving the stability of the power grid.

3. The ZDJ according to claim 1, characterized in that: in At the ideal no-load speed n0, the ZDJ circuit reaches cosα≈1, and its mechanical characteristics are similar to those of a DC shunt motor. As the ZDJ decreases from n0, the decrease in speed causes the frequency of the induced electromotive force in the rotor circuit to gradually increase, causing the capacitive reactance of the capacitor branch in [Figure 2] to gradually decrease while the inductive reactance gradually increases. This forms a slightly softened linear segment where the rotor current [I2] and the corresponding electromagnetic torque, which increase slowly as the slip increases, continue to decrease. However, after the speed continues to decrease to a certain point, the frequency of the rotor's induced electromotive force increases to the point where [I2] increases more slowly as the speed decreases, forming a soft and drooping stable segment of the mechanical characteristics in [Figure 3], making the mechanical characteristics of the ZDJ similar to those of an excavator. At this point, due to the ZDJ rotor... Compensation of the capacitor current in the container prevents the ZDJ mechanical characteristics from exhibiting the maximum electromagnetic torque and unstable segments of traditional asynchronous motors. When the remote control switch in the ZDJ activates too many squirrel cage bars, causing an excessive increase in the inductive portion, even significantly exceeding its capacitive portion, the ZDJ will exhibit extreme excavator characteristics, with its droop segment, or critical characteristic, parallel to the longitudinal axis. If the number of activated squirrel cage bars continues to increase, the droop segment of its characteristic will shift to the left, exceeding the critical characteristic and becoming the characteristic of an inductive asynchronous motor with an unstable droop segment. Therefore, the number of squirrel cage bars in the KTD must be appropriate, but the number of laminations can be set to a higher value. The ZDJ allows for convenient and rapid speed adjustment, simplifies the starting and speed control devices, and saves energy.

4. The KTD according to claim 1, characterized in that, In the design, the overall electrical performance, mechanical strength, and heat dissipation capacity should be given priority consideration. For example, selecting appropriate numbers, thicknesses, and electromagnetic characteristics of rotor laminations, isolation plates [G], and steel end plates, as well as an appropriate number of copper squirrel cage bars and steel connecting conductors, can achieve better electrical performance and increase the mechanical strength of the rotor. Two or three spiral heat dissipation channels with open ends and rotating around the rotor axis can also be set in the center of the KTD rotor, so that air can be automatically drawn into the holes to cool the rotor when it rotates. This will enable them to adapt to a wide range of speed regulation, high speed, or heavy load, and facilitate rotor heat dissipation and cooling to maintain normal operation. The KTD rotor can also be manufactured into a ceramic rotor by imitating the mature process of ceramic capacitors to further improve the rotor performance and significantly expand their market prospects.

5. The KTD according to claim 1 is characterized in that, after each squirrel cage bar and its end piece at one end are fixedly installed with an insulating pad and screws in the KTD, a remote control switch or inductive switch is provided to connect the squirrel cage bar and the end piece; while the other end of the squirrel cage bar is fixed to its end piece with screws and electrically connected; in this way, the on / off state of different squirrel cage bars can be controlled by the remote control switches or inductive switches of the KTD, and the diversity of RDJ and ZDJ performance and convenient speed adjustment are provided, thus enabling the KTD to create a new level of AC motor that can be adjusted and speed-regulated in real time.

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