A topological form of marine electric propulsion system

Abstract

The application discloses a kind of marine electric propulsion system topology, by propulsion motor, propulsion frequency converter, direct current power supply one and direct current power supply two are constituted, propulsion motor is double twenty-phase winding motor, propulsion frequency converter includes symmetrically arranged main circuit left channel and main circuit right channel, each channel includes four identical main circuit branch, each main circuit branch is by one five-phase three-level bridge arm unit and one five-phase filter unit Composition;The main circuit branch of each described propulsion frequency converter is connected with the corresponding single five-phase winding of the propulsion motor, and the neutral point of each group of five-phase winding is connected with the DC neutral point of the corresponding five-phase three-level bridge arm unit.The application compared with conventional three-phase marine electric propulsion system has the advantages of high reliability, small torque ripple, low vibration and noise, can effectively utilize harmonic output, input DC voltage is high, especially suitable for ship high-power electric propulsion.

Description

Technical Field

[0001] This invention belongs to the field of marine electric propulsion technology, and specifically relates to a marine electric propulsion system with a specific topology. Background Technology

[0002] Ship propulsion methods include two types: mechanical propulsion and electric propulsion. Mechanical propulsion is a propulsion method in which a prime mover such as a gas engine or diesel engine directly drives the propeller through a gearbox and shaft system. Electric propulsion is a propulsion method that combines the traditionally independent mechanical propulsion system and the electrical system into one system in the form of electrical energy, and comprehensively utilizes the ship's power station to provide propulsion power, auxiliary machinery and daily electricity to the entire ship.

[0003] Compared with traditional mechanical propulsion, electric propulsion has advantages such as flexible layout, efficient use of space, flexible operation, good maneuverability, low life-cycle cost, less maintenance, easy acquisition of ideal towing characteristics, low vibration and noise, and a more comfortable environment. It is one of the mainstream trends in the development of ship power.

[0004] Currently, conventional ship electric propulsion systems generally consist of a three-phase propulsion motor and a three-phase propulsion frequency converter, which have disadvantages such as low system redundancy, large torque pulsation of the propulsion motor, and relatively high vibration and noise.

[0005] In some special applications, low-voltage multiphase propulsion motor technology has emerged to improve the performance of propulsion systems. However, low-voltage multiphase propulsion motor technology has disadvantages such as relatively low input voltage and limited output power levels, making it difficult to fully meet user needs. Summary of the Invention

[0006] To overcome the shortcomings of conventional three-phase motor propulsion systems, such as low operational redundancy, large torque ripple, and high vibration and noise, as well as the relatively low input voltage and limited output power of low-voltage multiphase propulsion motor systems, this invention provides a marine electric propulsion system with a specific topology.

[0007] The technical solution adopted by this invention to solve its technical problem is as follows: a marine electric propulsion system in a topological form, comprising a multiphase propulsion motor, a dual-channel propulsion inverter, and two independent DC power supplies with identical parameters; the propulsion motor is a dual twenty-phase winding motor, with corresponding phases of the two sets of twenty-phase windings being independent and having the same phase; each set of twenty-phase windings is divided into four groups of five-phase windings with a 9-electrical-degree difference between them, each group of five-phase windings being star-connected, and the neutral point of each group of five-phase windings being led out; each phase winding is a concentrated winding, and the back electromotive force is a sine wave; the propulsion inverter includes a symmetrically arranged and independent main circuit left channel and a main circuit right channel, each channel including four identical and independent main circuit branches, each main circuit branch consisting of a five-phase three-level circuit. The system comprises a bridge arm unit and a five-phase filter unit including differential-mode and common-mode components; the first and third main circuit branches of the left main circuit channel and the second and fourth main circuit branches of the right main circuit channel are powered by DC power supply one; the first and third main circuit branches of the right main circuit channel and the second and fourth main circuit branches of the left main circuit channel are powered by DC power supply two; the output terminals of the four main circuit branches of the left main circuit channel are sequentially connected to a single five-phase winding of a set of twenty-phase windings of the propulsion motor; the output terminals of the four main circuit branches of the right main circuit channel are sequentially connected to a single five-phase winding of another set of twenty-phase windings of the propulsion motor; the neutral point of each five-phase winding is connected to the DC neutral point of the corresponding five-phase three-level bridge arm unit.

[0008] The aforementioned marine electric propulsion system, comprising a DC power supply, the first and third main circuit branches of the left main circuit channel, the second and fourth main circuit branches of the right main circuit channel, and the corresponding twenty-phase windings of the propulsion motor, and a subsystem comprising a DC power supply, the first and third main circuit branches of the right main circuit channel, the second and fourth main circuit branches of the left main circuit channel, and the corresponding other twenty-phase windings of the propulsion motor, can all operate independently.

[0009] The aforementioned marine electric propulsion system with a topology includes four sets of five-phase windings: the first set of twenty-phase windings, consisting of the first set of five-phase windings A11~E11, the second set of five-phase windings A21~E21, the third set of five-phase windings A31~E31, and the fourth set of five-phase windings A41~E41.

[0010] The aforementioned marine electric propulsion system with a topology includes four sets of five-phase windings: the first set of five-phase windings A12~E12, the second set of five-phase windings A22~E22, the third set of five-phase windings A32~E32, and the fourth set of five-phase windings A42~E42 of the second set of twenty-phase windings.

[0011] The beneficial effects of this invention are: 1. This invention increases the system output power by employing a multi-phase propulsion motor and a propulsion inverter of the dual-channel multi-branch three-level bridge arm unit type; 2. This invention improves system redundancy and reliability by employing two independent DC power supplies, dividing the frequency converter into independent left and right channels, each channel into four independent main circuit branches, and two independent sets of dual twenty-phase winding drive motors. Furthermore, by using DC power supply one to power the first and third main circuit branches of the left main circuit channel and the second and fourth main circuit branches of the right main circuit channel, and DC power supply two to power the first and third main circuit branches of the right main circuit channel and the second and fourth main circuit branches of the left main circuit channel, and by ensuring that each twenty-phase winding subsystem can operate independently, the invention further improves system redundancy and reliability. 3. This invention reduces the harmonics of the synthetic magnetic field of the propulsion motor, thereby reducing torque pulsation and vibration noise, by employing four groups of five-phase, twenty-phase windings with a 9-electrical-degree difference between each phase; further reduces torque pulsation and vibration noise by using a sinusoidal phase winding back EMF method; and effectively suppresses differential-mode and common-mode harmonic voltages at the inverter output by employing a five-phase three-level bridge arm unit and a five-phase differential-mode and common-mode filter unit for each main circuit branch, further reducing torque pulsation and vibration noise of the propulsion motor. 4. This invention improves the utilization rate of motor winding materials by adopting a centralized type of motor phase winding; by connecting the neutral point of each group of five-phase windings to the DC neutral point of the corresponding five-phase three-level bridge arm unit, the effective utilization of the 3rd and 5th harmonic phase currents of the motor is realized, further improving the torque density of the propulsion motor and the utilization rate of motor materials. 5. Compared with conventional three-phase motor propulsion systems, this invention has advantages such as high operational redundancy, low torque pulsation, low vibration and noise, effective utilization of harmonics, and effective suppression of differential-mode and common-mode harmonic voltages. Compared with low-voltage multiphase motor propulsion systems, it has advantages such as higher input voltage and higher output power. It is particularly suitable for special occasions with high requirements for propulsion power level, operational redundancy, torque pulsation, vibration and noise, harmonic utilization, and suppression of differential-mode and common-mode harmonic voltages, such as high-power electric propulsion for comfort-oriented ships. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the structure of the present invention.

[0013] The labels for each figure are as follows: 1—propulsion motor, 2—propulsion inverter, 3—DC power supply one, 4—DC power supply two, 5—main circuit left channel, 6—main circuit right channel, 7—main circuit branch, 8—five-phase three-level bridge arm unit, 9—filter unit, 10—phase winding. Implementation

[0014] To make the objectives, technical solutions, and advantages of this invention clearer, the various embodiments of this invention will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the various embodiments of this invention to facilitate a better understanding of this application. However, the technical solutions claimed in the claims of this application can be implemented even without these technical details and with various variations and modifications based on the following embodiments.

[0015] like Figure 1 As shown, the present invention provides a marine electric propulsion system with a topology including a dual twenty-phase propulsion motor 1, a dual-channel propulsion frequency converter 2, a DC power supply 3, and a DC power supply 4.

[0016] The aforementioned propulsion motor 1 is a dual twenty-phase winding motor, with two sets of twenty-phase windings that are independent of each other and have the same phase; each set of twenty-phase windings is divided into four groups of five-phase windings (e.g., Figure 1 The first set of twenty-phase windings consists of four groups of five-phase windings: A11-E11, A21-E21, A31-E31, and A41-E41. The second set of twenty-phase windings consists of four groups of five-phase windings: A12-E12, A22-E22, A32-E32, and A42-E42. The four groups of five-phase windings are sequentially separated by 9 electrical degrees. Each group of five-phase windings is connected in a star configuration, and the neutral point of each group of five-phase windings is brought out. Each phase winding is a concentrated winding, and the back EMF of each phase winding is a sine wave. This design aims to improve the utilization rate of motor winding materials, reduce the harmonics of the combined magnetic field of the propulsion motor, reduce the vibration and noise of the propulsion motor, and improve the operational redundancy of the motor.

[0017] The aforementioned drive inverter 2 includes a symmetrically arranged and independent main circuit left channel 5 and a main circuit right channel 6. Each channel includes four identical and independent main circuit branches 7 (e.g., Figure 1 The left and right channels have branches 11, 21, 31, and 41, and the right channel has branches 12, 22, 32, and 42. Each main circuit branch 7 consists of a five-phase three-level bridge arm unit 8 and a five-phase filter unit 9. Each five-phase filter unit 9 includes differential mode and common mode components to improve the system input voltage and output power, enhance the redundancy and reliability of the inverter operation, and suppress the differential mode and common mode harmonic voltages of the inverter output.

[0018] The DC power supply 3 and DC power supply 4 are independent of each other and have the same parameters, so as to improve the redundancy of system operation and enhance the reliability of system operation.

[0019] The first and third main circuit branches 7 of the left main circuit channel 5 and the second and fourth main circuit branches 7 of the right main circuit channel 6 are powered by DC power supply 3; the first and third main circuit branches 7 of the right main circuit channel 6 and the second and fourth main circuit branches 7 of the left main circuit channel 5 are powered by DC power supply 4, so as to improve the system operation redundancy and enhance the system operation reliability.

[0020] The output terminals of the four main circuit branches 7 of the left main circuit channel 5 are sequentially connected to the single five-phase windings of the corresponding twenty-phase windings of the propulsion motor 1, one by one; the output terminals of the four main circuit branches 7 of the right main circuit channel 6 are sequentially connected to the single five-phase windings of the other twenty-phase windings of the propulsion motor 1, one by one, in order to reduce the harmonics of the synthesized magnetic field of the propulsion motor 1, reduce the torque pulsation and vibration noise of the propulsion motor 1.

[0021] The neutral point of each group of five-phase windings of the motor is connected to the DC neutral point of the corresponding five-phase three-level bridge arm unit 8 to enhance the utilization effect of the third and fifth harmonic phase currents of the propulsion motor and further improve the torque density of the propulsion motor.

[0022] The subsystem consisting of DC power supply 3, the first and third main circuit branches 7 of the left main circuit channel 5, the second and fourth main circuit branches 7 of the right main circuit channel 6, and a set of twenty-phase windings of the propulsion motor, and the subsystem consisting of DC power supply 4, the first and third main circuit branches 7 of the right main circuit channel 6, the second and fourth main circuit branches 7 of the left main circuit channel 5, and another set of twenty-phase windings of the propulsion motor, can all operate independently to improve system redundancy and enhance system reliability.

[0023] Those skilled in the art will understand that the above embodiments are specific examples of implementing the present invention, and in practical applications, various changes in form and detail may be made without departing from the spirit and scope of the present invention.

Claims

1. A marine electric propulsion system with a specific topology, characterized in that: It consists of a propulsion motor (1), a dual-channel propulsion frequency converter (2), and two independent DC power supplies with the same parameters, namely DC power supply 1 (3) and DC power supply 2 (4). The propulsion motor (1) is a double twenty-phase winding motor. The corresponding phases of the two sets of twenty-phase windings are independent of each other and have the same phase. Each set of twenty-phase windings is divided into four groups of five-phase windings with a difference of 9 electrical angles. Each group of five-phase windings is connected in a star configuration. The neutral point of each group of five-phase windings is led out. Each phase winding (10) is a concentrated winding with a back EMF of sine wave. The drive inverter (2) includes a symmetrically arranged and mutually independent main circuit left channel (5) and a main circuit right channel (6). Each channel includes four main circuit branches (7) that are identical and mutually independent. Each main circuit branch (7) consists of a five-phase three-level bridge arm unit (8) and a five-phase filter unit (9) that includes differential mode and common mode parts. The first and third main circuit branches (7) of the left channel (5) of the main circuit and the second and fourth main circuit branches (7) of the right channel (6) of the main circuit are powered by DC power supply one (3); the first and third main circuit branches (7) of the right channel (6) of the main circuit and the second and fourth main circuit branches (7) of the left channel (5) of the main circuit are powered by DC power supply two (4); The output ends of the four main circuit branches (7) of the left channel of the main circuit (5) are sequentially connected to the single five-phase winding of a set of twenty-phase windings of the propulsion motor (1); the output ends of the four main circuit branches (7) of the right channel of the main circuit (6) are sequentially connected to the single five-phase winding of another set of twenty-phase windings of the propulsion motor (1). The neutral point of each group of five-phase windings is connected to the DC neutral point of the corresponding five-phase three-level bridge arm unit (8); The subsystem consisting of DC power supply one (3), the first and third main circuit branches (7) of the left channel of the main circuit (5) and the second and fourth main circuit branches (7) of the right channel of the main circuit (6) and the corresponding twenty-phase windings of the propulsion motor, and the subsystem consisting of DC power supply two (4), the first and third main circuit branches (7) of the right channel of the main circuit (6) and the second and fourth main circuit branches (7) of the left channel of the main circuit (5) and the corresponding other twenty-phase windings of the propulsion motor, operate independently; The four sets of five-phase windings are the first set of twenty-phase windings, namely the first set of five-phase windings A11~E11, the second set of five-phase windings A21~E21, the third set of five-phase windings A31~E31, and the fourth set of five-phase windings A41~E41; The four sets of five-phase windings are the first set of five-phase windings A12~E12, the second set of five-phase windings A22~E22, the third set of five-phase windings A32~E32, and the fourth set of five-phase windings A42~E42 of the second set of twenty-phase windings.

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