Pole-changing Induction Research Articles

Dynamic Loss Minimization Control of a 4-Pole/2-Pole Electronic Pole-Changing Induction Motor Using a Look-Up Table

Dynamic Loss Minimization Control of a 4-Pole/2-Pole Electronic Pole-Changing Induction Motor Using a Look-Up Table

Control of a 4-Pole/2-Pole Electronic Pole-Changing Induction Motor for Traction Applications

Control of a 4-Pole/2-Pole Electronic Pole-Changing Induction Motor for Traction Applications

Gradual Electronic Pole Changing Technique to Minimize the Circulating Currents During Pole/Mode Transition in Induction Motor Drive

This paper proposes a control strategy for the electronic pole changing (EPC) induction motor drive (IMD) for the transition between 3-ϕ,12-pole mode to 9-ϕ,4-pole mode. The proposed control strategy employs a gradual electronic pole changing (GEPC) technique which linearly demagnetizes the IMD winding from 3-ϕ,12-pole and magnetizes progressively to 9-ϕ,4-pole mode. The proposed GEPC technique is also compared with the instantaneous EPC technique for its performance. The proposed GEPC solution eliminates the issue of the circulating current, which exists in the instantaneous EPC technique and is responsible for negative torque generation during pole transition from 3-ϕ mode to 9-ϕ mode. Apart from eliminating the circulating current, the proposed GEPC strategy also sorts out various typical issues which exist in instantaneous EPC technique during pole/mode transition. The various issues in the instantaneous mode transition are (i) absence of interlocking between stator and rotor fields, (ii) oscillations in the flux between the 12-pole (3-ϕ) and 4-pole (9-ϕ), (iii) strengthening and weakening 4-pole formations in stator and rotor, (iv) distorted flux and pole formations, (v) dip in speed, and (vi) high oscillations/ripple content in torque and speed. Ansys simulation is done using Maxwell 2-D integrated with Twin-builder for EPC IMD for instantaneous and proposed GEPC techniques. Further, the paper presents the experimental results to validate the simulation studies.

48 V Starter-Generator Induction Machine With Pole-Changing Windings

An electronic pole-changing winding induction machine with eight and four poles for a 48-V starter-generator application is studied in this article. Starter-generators require high torque capability for short durations at low speed for cranking, a wide flux weakening region for regeneration, as well as high torque density, so that the machine may be integrated into a drive train with minimum change to the existing system. In this article, it is shown that when pole-changing windings are used, the axial length of the machine can be reduced compared to the baseline induction machine design, resulting in a more compact machine. The effects of shorter stack length and pole-changing windings on the performance of the induction machine are studied. Efficiency, loss, and power factor maps are calculated with analytical and finite-element methods and experimentally validated to compare the performance of the pole-changing winding induction machine with a baseline design under various operating conditions.

Magnetization Analysis for Pole-Changing Permanent Magnet Motor

Vlado Ostovic first proposed pole-changing permanent magnet motor. In his paper, the stator was the same with that of pole-changing induction motor, the rotor was built following the sandwich principle, and some of the stator winding are used as the magnetizing coil. But the rotor structure has many shortcomings. The surface-mounted rotor is advised in this paper. The magnetizing magnetic field by some of the stator windings is calculated, and we find the magnetic field is complex. The direction of the remanence of the permanent magnet is decided by both the radial and tangential component of magnetic field. We also calculate the magnetizing process of permanent magnet by FEM software.

Harmonic Reduction in DC-Link Current of a Dual-Inverter Pole-Changing Induction Motor Drive for Electric Vehicles

In electric vehicles, the DC-link current harmonics of the motor drive can seriously affect the battery management device and even the battery life. The purpose of this paper is to analyze the DC-link current of a newly developed dual-inverter pole-changing induction motor drive, and hence to suppress its harmonic contamination. The key is to employ newly the double Fourier series to model the harmonic current in the DC link of the dual inverter, which adopts a special arrangement of space-vector pulse-width modulation. Digital-signal processor-based implementation and experimentation are given to verify the theoretical analysis.

Spectral analysis of a new six-phase pole-changing induction motor drive for electric vehicles

In this paper, a new six-phase pole-changing induction motor drive is proposed to extend the constant-power operating range for electric vehicle application. The double Fourier series is newly employed to analyze the spectra of the motor phase voltage and current. Consequently, the harmonic expression of the inverter DC-link current can be derived. In order to reduce the DC-link harmonics, a new sinusoidal pulsewidth-modulation strategy is developed for the proposed six-phase inverter. Experimental results, particularly the spectra of the phase current and the DC-link current, are given to verify the theoretical analysis.

Performance Analysis of a New Dual-Inverter Pole-Changing Induction Motor Drive for Electric Vehicles

In this paper, a new dual-inverter pole-changing induction motor drive is proposed and analyzed. The keys are to adopt a new pole-changing induction motor to extend the constant-power operating range and to develop a new dual-inverter to reduce the harmonic torques (hence the acoustic noise). The corresponding maximum torque capability and harmonic torque cancellation are particularly analyzed and discussed. Experimental results are given to verify the theoretical analysis.

A Study of the Smooth Pole Change Operation Method of A Six-Phase pole Change Induction Motor for Electric Vehicles

A Study of the Smooth Pole Change Operation Method of A Six-Phase pole Change Induction Motor for Electric Vehicles

Transient performance analysis of a six-phase pole change induction motor for electric vehicles

We previously proposed a six-phase pole change induction motor (six-phase PCIM) for electric vehicles (EVs), and have presented its operating principle and steady state characteristics. The six-phase PCIM expands the constant power operation range using the pole change technique without mechanical contactors; therefore it possesses superb characteristics for miniaturizing EV driving systems. This paper proposes a new analysis method for the six-phase PCIM in order to derive basic equations which can be used to analyze transient phenomena caused by pole change and to create control methods. First, a “six-phase tensor-transformed rotational d-q axis” is defined and its physical meaning made clear. By using this axis, voltage and torque equations which can uniformly deal with the steady state and transient states will be derived. Next, we compare measured and simulated results of voltage, current, and torque characteristics in steady state and in transient states at the pole change operation and both-pole dual operation. Through these comparisons, the validity of our theory and its effectiveness to performance analysis and application to the control method for the six-phase PCIM is discussed in detail. © 1997 Scripta Technica, Inc. Electr Eng Jpn, 120(2): 59–71, 1997

Transient performance analysis of a six‐phase pole change induction motor for electric vehicles

Transient performance analysis of a six‐phase pole change induction motor for electric vehicles

Basic principle and maximum torque characteristics of a six-phase pole change induction motor for electric vehicles

In addition to basic characteristics such as small size, lightweight and easy maintenance, the electric vehicle (EV) motor is required to possess characteristics that allow for the production of high torque in low-speed region and to realize a wide-speed range of constant power in high-speed region. In an attempt to improve further the constant power operation of the induction motor (IM), this paper proposes a six-phase pole change IM (six-phase PCIM). The six-phase PCIM further expands the constant power operation range without increasing either volume or current of IM. To clarify the basic principle and torque characteristics of the six-phase PCIM, its winding method and distribution of magnetomotive force (mmf) will first be examined. Then, by establishing a performance calculation method based on a quasisinusoidal wave method, the feasibility of a highly precise performance calculation sufficient for actual use will be demonstrated. Furthermore, by clarifying through experiment the maximum torque characteristics, the feasibility of expansion of the constant power operation range will be confirmed and its effectiveness in the EV will be discussed. © 1997 Scripta Technica, Inc. Electr Eng Jpn, 118 (3): 78–91, 1997

A Control Method of an Inverter-Fed Six-Phase Pole Change Induction Motor for Electric Vehicles.

In attempt to improve the constant power operation properties of the induction motor (hereafter, IM) for electric vehicles, we have developed a six- phase pole change IM (hereafter, six-phase PCIM). The six- phase PCIM can expand the constant power operation range without increasing the volume and current of IM. This advantage is realized by making use of the difference of the IM's maximum torque in the dissimilarity in the number of poles.This paper can be summarized as follows:A six- phase PCIM which can be operated as 4-pole and 8-pole is smaller than a 4-pole IM with the same rating.The method of vector control based on the six- phase to two pairs of rotational d- q axis transformation is established.When a six-phase PCIM is operated with a six-phase inverter, a mechanical contactor to change the number of poles is not necessary and the pole change is carried out automatically at the proper speed.The pole change can be done smoothly without the large torque variation by the technique of controlling the flux levels of both modes independently.The characteristics of the proposed control method are shown through the simulations and experimental results, and the usefulness of this control method for the electric vehicle drive system is made clear.

A Study of Electromagnetic Vibration for Pole-changing Induction Motor with Pole Amplitude Modulation. Pole Changing from 8-pole to 10-pole by Pole-Amplitude Modulation.

A Study of Electromagnetic Vibration for Pole-changing Induction Motor with Pole Amplitude Modulation. Pole Changing from 8-pole to 10-pole by Pole-Amplitude Modulation.

Transient Performance Analysis of A Six-Phase Pole Change Induction Motor for Electric Vehicles.

We have already proposed a six-phase pole change induction motor (six-phase PCIM) for electric vehicles (EV), and have been making clear about its operation principle and steady state characteristics. The six-phase PCIM further expands the constant power operation range using the pole change technique without mechanical contactors, therefore it possesses the superb characteristics to miniaturize the EV's driving systems.This paper proposes a new analyzing method for the six-phase PCIM in order to derive the basic equations which can be utilized to analyze the transient phenomena caused by pole change and to create the control methods. First, a “six-phase tensor-transformed rotational d-q axis” (provisional name) will be defined, and its physical meanings will be made clear. By using this axis, the voltage and torque equations which can uniformly deal with the steady state and the transient state will be derived.Next, comparative examinations between the measured results and the simulated results regarding the voltage, current and torque characteristics on the steady state and the transient state at the pole change operation and the both poles dual operation will be achieved. Through these examinations, the propriety of this theory and its effectiveness in the further detail performance analysis and the application to the control method for the six-phase PCIM will be discussed.

Electric Vehicle Related Technologies. Basic Principle and Maximum Torque Characteristics of A Six-Phase Pole Change Induction Motor for Electric Vehicles.

In addition to basic characteristics such as a small size, light weight and easy maintenance, the electric vehicle (EV) motor is required to possess characteristics which allow for the production of a high torque at a low speed region and to realize a wide range of constant power operation at a high speed region.In an attempt to further improve the constant power operation properties of the induction motor (IM), this paper proposes a six-phase pole change IM (six-phase PCIM). The six-phase PCIM further expands the constant power operation range without increasing the volume and current of IM.To clarify the basic principle and the torque characteristics of the six-phase PCIM, first, its winding method and distribution of mmf will be examined. Next, by establishing a performance calculation method based on quasi-sinusoidal wave method, the feasibility of a highly precise performance calculation sufficient for actual use will be demonstrated. Furthermore, by clarifying the maximum torque characteristics through experiment, the feasibility of the expansion of the constant power operation range will be confirmed and its effectiveness in the EV will be discussed.

An Examination of Inductance Matrices and Winding Factors of Pole-Changing Induction Motor with Pole-Amplitude Modulation. Pole Changing from 8-pole to 6-pole by Pole-Amplitude Modulation.

A pole-changing induction motor with pole-amplitude modulation (PAM) has a single-winding system, and has a unique speed ratio other than 1: 2. It provides an excellent energy-saving property when used for the flow control system of pumps and blowers. This, therefore, has attracted considerable attention in a field of flow control design.However the method of conversion from an 8-pole to a 6-pole induction motor by using this PAM becomes complicated compared with the method of conversion to a 10-pole motor. In addition, the induction motor designed by this approach is likely to be affected by large harmonic magnetomotive forces, and therefore needs careful investigation in the design.This paper describes the harmonic torque prevention approach done by using the unified theory of electrical machinery for the case of 8-pole to 6-pole conversion by PAM. From the result of analysis and speed-torque experiment, it is shown that this induction motor is driven by the negative-phase revolving magnetic field due to the 3rd order harmonic, and that there appear 13th harmonic asynchronous crawling torque in motor region and 11th harmonic asynchronous torque in braking region. It is also shown that a long-pitch winding with a machine angle of 8/24 is recommended for the motor design so that the 11th and the 13th harmonic torques are removed.

Analysis and an Improvement of Transient Characteristics of Pole-Changing Induction Motor with Single Primary Winding.

Pole-changing is a simple method for changing the speed of a cage induction motor. However, excessive currents and torques appear during deceleration of the motor by pole-changing. These characteristics are unfavorable for shafts and couplings of the motor system. And further, these cause the sudden voltage drop of the supply. From user's viewpoint, it is desirable to control these currents and torques as low as possible.In order to decelerate the speed by pole-changing, first, the supply is removed from the delta connected high speed terminals. Next, the supply is connected to low speed terminals, and finally, the winding is changed to the parallel _??_ connection. From the simulation results, the authors discuss the effects of the supply removal period, impressed voltage phase and the period between the supply impression and the changing to the parallel _??_ on the motor. This discussion gives the conclusion that the transient current and torque can not sufficiently controlled even when the above conditions are appropriately selected.In order to reduce these transient current and torque sufficiently, this paper proposes a method in which external resistors are inserted in series with the three-phase primary winding. From the simulation results, it is found that the inserted resistance of 1.55 times the locked rotor impedance of the induction motor, can sufficiently reduce the excessive transients.

Calculation Method of Characteristic by Equivalent Circuit for Pole-Changing Induction Motor with Pole-Amplitude Modulation. Pole Changing from 8-pole to 10-pole by Pole-Amplitude Modulation.

A pole-changing induction motor with pole-amplitude modulation allows a speed ratio other than 1:2 using a single winding. Furthermore it has a good energy-saving performance when used for the flow rate control of pump or blower, and also it provides a low manufacturing cost. However, the pole-changing induction motor with pole-amplitude modulation has a problem that its simple calculation method of characteristics has not been presented.A purpose of this paper is to derive the calculation method by using an equivalent circuit in when an 8-pole cage type induction motor is changed into a 10-pole motor by pole-amplitude modulation. In this paper, the authors suggest the equivalent circuit in which the space harmonic effects are considered, because the 10-pole motor has large harmonic magnetomotive forces. This paper also describes a simple determination method of equivalent circuit constants.Torque-slip characteristics and output-characteristics are obtained, and it has been confirmed that they agree well with the experimental values. This calculation method of characteristic is practical and useful for the future designing of pole-changing induction motors with pole-amplitude modulation.

Chopper-controlled wind-driven self-excited induction generators

Two chopper circuit configurations, one with voltage commutation, are shown to be useful for obtaining a controllable DC voltage from wind-driven self-excited pole-changing induction generators. For the case of a resistive load, expressions for the average load voltage and power are derived, and a set of normalized curves relating the voltage ratio and time ratio is drawn. Experimental results on a self-excited induction generator with a 4/6-pole combination using these choppers fully demonstrate the utility of the setup as a whole. Test results on an induction generator controlled by DC choppers demonstrate that any desired load voltage up to a maximum of input voltage can be maintained easily by varying the time period in the case of a load-commutated chopper and the on-off-time ratio in the case of a voltage-commutated chopper.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>