CN102638116A - Multi-phase permanent-magnet high-voltage wind driven generator and system thereof - Google Patents

Abstract

The invention discloses a multi-phase permanent magnet high-voltage wind power generator, which includes a stator and a rotor. The stator is composed of a stator yoke, stator teeth, copper wires and insulation, and the rotor is composed of a rotating shaft, a permanent magnet, a weight reduction hole and a rotor core. The stator is divided into lobes, each lobe is a unit motor, and the stator winding is a multi-phase winding structure; a multi-phase permanent magnet high-voltage wind power generator system is also disclosed, including a fan, a multi-phase power generation as claimed in any one of claims 1 to 8 Generator, PWM rectifier and cascaded grid-connected inverter, fan is connected to multi-phase generator, and each phase generator is connected to PWM rectifier to achieve unit voltage stabilization, and then through H-bridge unit cascaded grid-connected inverter to achieve integration with 6kV-10kV high-voltage grid connected to the grid for power generation. The invention can be used for wind power generation. The number of motor phases increases, and the current value of each phase decreases, which reduces the requirements for the capacity of power switching devices; at the same time, it can improve the reliability of the system and facilitate maintenance.

Description

Multi-phase permanent magnet high-voltage wind turbine and its system

technical field

The invention relates to the technical field of wind power generation, and relates to a multi-phase permanent magnet high-voltage wind power generator and a system thereof.

Background technique

In the context of the rapid development of the global wind power industry, the capacity of a single wind turbine continues to grow. Due to the traditional wind turbine output voltage of 690V, when developing to a large-capacity wind turbine, the motor stator current is too large and the heat generation is large. It is easy to cause the motor to burn out and reduce the service life of the motor; secondly, due to the low voltage and large line loss, both onshore wind power and offshore wind power systems need to be equipped with additional transformers. The complex cooling system is not conducive to its long-term operation.

Contents of the invention

At present, wind turbines have problems such as high cost, low output voltage, large current, and high loss.

In order to solve the above problems, a multi-phase permanent magnet high-voltage wind power generator includes a stator and a rotor. The stator is composed of a stator yoke, stator teeth, copper wires and insulation, and the rotor is composed of a rotating shaft, permanent magnets, weight reduction holes and a rotor core. The stator is divided into lobes, each lobe is a unit motor, and the stator winding is a multi-phase winding structure.

Further, as a preferred solution, the stator windings are designed to have fifteen phases.

Furthermore, the stator winding is composed of five sets of three-phase windings, and the connection method of each set of windings is the same as that of an ordinary three-phase motor, that is, the windings are 120° electrical angle apart from each other in space, and the windings of each set are 12° apart from each other in space. ° electrical angle.

Further, as a preferred solution, the stator windings are designed to have eighteen phases.

Further, as a preferred solution, the stator winding consists of six sets of three-phase windings, and the connection of each set of windings is the same as that of an ordinary three-phase motor, that is, the windings are 120° electrical angle apart from each other in space, and each set of windings They are spatially different from each other by 10° electrical angle.

Further, as a preferred solution, each set of windings has three outlets connected to the rectification and inverter system.

Further, as a preferred solution, the stator yoke and the stator teeth are made of silicon steel sheets and adopt rectangular slots.

Further, as a preferred solution, the rotor core is formed by stacking silicon steel sheets.

Further, as a preferred solution, the permanent magnets are placed on the surface of the rotor or embedded in the rotor, and the permanent magnets are arranged on the surface of the rotor with staggered polarities by way of radial magnetization.

The invention also discloses a multi-phase permanent magnet high-voltage wind power generator system, including a fan, a multi-phase generator according to one of claims 1 to 8, a PWM rectifier and a cascaded grid-connected inverter, the fan and a multi-phase The generators are connected, and the generators of each phase are connected with PWM rectifiers to achieve unit voltage stabilization, and then through the H-bridge unit cascaded grid-connected inverters to realize grid-connected power generation with 6kV-10kV high-voltage grid.

Since the generator outputs a line voltage of 6000-10000 volts, the existing rectification system cannot withstand such a high voltage, so it is designed as a multi-phase motor. As the number of motor phases increases, the output voltage of each phase will decrease, and the current of each phase will decrease. Small, so as to adapt to the rectification and inverter system and reduce the requirements for the capacity of power switching devices. After the generator is rectified and invertered, it outputs AC with a three-phase line voltage of 6,000-10,000 volts, which is directly sent to the grid, eliminating the need for a step-up transformer for grid connection. For large-capacity permanent magnet wind turbines, the stator can be divided into two parts, each part is a unit motor, and each unit motor can be disassembled separately for easy maintenance.

Description of drawings

A more complete and better understanding of the invention, and many of its attendant advantages, will readily be learned by reference to the following detailed description when considered in conjunction with the accompanying drawings, but the accompanying drawings illustrated herein are intended to provide a further understanding of the invention and constitute A part of the present invention, the exemplary embodiment of the present invention and its description are used to explain the present invention, and do not constitute an improper limitation of the present invention, wherein:

Fig. 1 Schematic diagram of the three-dimensional structure of the wind turbine stator and rotor;

Fig. 2 is a schematic diagram of a radial cross-sectional structure of a wind turbine stator;

Fig. 3 is a schematic diagram of a radial cross-sectional structure of a wind turbine rotor;

Fig. 4 is a schematic diagram of multi-phase high-voltage wind turbine stator splitting;

Fig. 5 is a structural block diagram of a high-voltage, multi-phase wind power generation system;

Fig. 6 is a control block diagram of an eighteen-phase high-voltage wind power generation system;

Fig. 7 is a control block diagram of the fifteen-phase high-voltage wind power generation system.

Detailed ways

Embodiments of the present invention will be described below with reference to FIGS. 1-7.

In order to make the above objects, features and advantages more comprehensible, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

Example 1

As shown in Figures 1 to 3, the present invention provides a multi-phase permanent magnet high-voltage wind power generator, including a stator 100 and a rotor 200, the stator 100 is composed of a stator yoke 1, stator teeth 2, copper wires 3 and insulation 4, and the rotor 200 is composed of a rotating shaft 5, a permanent magnet 6, a weight reducing hole 7 and a rotor core 8. The stator 100 is divided into lobes, each lobe is a unit motor 101, and the winding of the stator 100 is a multi-phase winding structure.

The wind engine is designed as a multi-phase motor, which improves the stability of the wind power generation system and reduces the requirement on the capacity of power electronic devices.

Example 2

As shown in Figure 6, a multi-phase permanent magnet high-voltage wind power generator, the stator winding is designed to be eighteen phases, and the stator winding is composed of six sets of three-phase windings, and the connection method of each set of windings is the same as that of an ordinary three-phase motor. The method is the same, that is, the windings are spatially different from each other by 120° electrical angle, and each set of windings is spatially different from each other by 10° electrical angle.

Example 3

As shown in Figure 7, a multi-phase permanent magnet high-voltage wind power generator, the stator winding is designed to be fifteen phases, and the stator winding is composed of five sets of three-phase windings, and the connection method of each set of windings is the same as that of an ordinary three-phase motor. The method is the same, that is, the windings are spatially different from each other by 120° electrical angle, and each set of windings is spatially different from each other by 12° electrical angle.

Example 4

As shown in Fig. 5, a multi-phase permanent magnet high-voltage wind power generator system includes a fan 10, a multi-phase generator 20 according to one of claims 1 to 8, a PWM rectifier 30 and a cascaded grid-connected inverter 40 , the fan 10 is connected to the multi-phase generator 20, and the motor 20 of each phase is connected to the PWM rectifier 30 to realize unit voltage stabilization, and then the H-bridge unit cascaded grid-connected inverter 40 is used to realize grid-connected power generation with the 6kV-10kV high-voltage grid.

In order to reduce the cost of wind power generation and improve the characteristics of low output voltage, large current and high loss of traditional wind power generators, the present invention proposes a multi-phase permanent magnet high-voltage wind power generator and its drive control system. The output voltage of the motor is relatively high , to reduce motor loss and heat generation; designed as a multi-phase motor, the stability of the wind power generation system is improved, and the requirements for the capacity of power electronic devices are reduced. The drive control system uses a PWM rectifier 30 to realize unit voltage stabilization, and then realizes grid-connected power generation with a 6kV-10kV high-voltage grid through an H-bridge unit cascaded grid-connected inverter 40 .

The stator winding is designed to be 15-phase or 18-phase, and the rotor is placed with a permanent magnet. After the rectification and inverter system, the output line voltage is 6000-10000 volts, and then sent to the grid. The generator is a multi-phase winding output, using PWM rectification control technology to achieve a stable output voltage for each unit, and a cascaded working mode between the units to achieve single-phase high-voltage output.

The stator winding has fifteen or eighteen outlets, and each winding has three outlets connected to the rectification and inverter system.

The stator cores 1 and 2 are formed by stacking silicon steel sheets, and the stator adopts rectangular slots.

The rotor core 8 is made of silicon steel sheets, the permanent magnets 6 are placed on the rotor surface or embedded in the rotor, and the permanent magnets 6 are arranged on the rotor surface with staggered polarities by means of radial magnetization.

The drive control part of the wind power generation system includes a PWM rectifier at the generator side, a PWM inverter at the grid side, and low voltage ride-through performance control.

The generator-side PWM rectifier adopts a double-closed-loop control strategy of voltage outer loop and current inner loop to realize constant unit power factor and DC terminal voltage.

The grid-side PWM inverter uses low-voltage devices to form a plurality of power units cascaded to realize high-voltage output, and the step-down transformer on the input side adopts a phase-shifting method.

The low-voltage ride-through performance control technology is to connect the unloading resistor in parallel at the DC terminal, and consume a part of the energy by controlling the conduction time of the unloading resistor during the low-voltage ride-through period, so as to reduce the current of the subsequent stage connected to the grid and protect the subsequent stage. device.

As mentioned above, although the Example of this invention was demonstrated in detail, it is obvious to those skilled in the art that many modifications can be made as long as the inventive point and effect of this invention are not substantially deviated. Therefore, all such modified examples are also included in the protection scope of the present invention.

Claims (10)

1. A multi-phase permanent magnet high-voltage wind-driven generator, comprising a stator and a rotor, the stator is made up of a stator yoke, stator teeth, copper wires and insulation, and the rotor is made up of a rotating shaft, a permanent magnet, a lightening hole and a rotor core, and is characterized in that : The stator is divided into lobes, each lobe is a unit motor, and the stator winding is a multi-phase winding structure. 2. A multi-phase permanent magnet high-voltage wind power generator according to claim 1, characterized in that: the stator windings are designed to have fifteen phases. 3. A kind of polyphase permanent magnet high-voltage wind-driven generator as claimed in claim 2, it is characterized in that: stator winding is made up of five sets of three-phase windings, and the connection method of each set of windings is the same as that of common three-phase motors, That is, the windings are spatially different from each other by an electrical angle of 120°, and the sets of windings are spatially different from each other by an electrical angle of 12°. 4. A multi-phase permanent magnet high-voltage wind power generator according to claim 1, characterized in that: the stator windings are designed to be eighteen phases. 5. A kind of polyphase permanent magnet high-voltage wind-driven generator as claimed in claim 4, it is characterized in that: stator winding is made up of six sets of three-phase windings, and the connection method of each set of windings is the same as that of common three-phase motors, That is, the windings are spatially different from each other by an electrical angle of 120°, and the sets of windings are spatially different from each other by an electrical angle of 10°. 6. A multi-phase permanent magnet high-voltage wind power generator as claimed in claim 2 or 4, characterized in that: each set of windings has three outlets connected to a rectification and inverter system. 7. A multi-phase permanent magnet high-voltage wind power generator as claimed in claim 1, characterized in that: the stator yoke and the stator teeth are made of silicon steel sheets and adopt rectangular slots. 8. A multi-phase permanent magnet high-voltage wind power generator according to claim 1, characterized in that: the rotor core is made of silicon steel sheets. 9. A multi-phase permanent magnet high-voltage wind power generator as claimed in claim 1, characterized in that: the permanent magnets are placed on the surface of the rotor or embedded in the rotor, and the permanent magnets are arranged in a radial magnetization manner with staggered polarities rotor surface. 10. A multi-phase permanent magnet high-voltage wind power generator system, characterized in that it includes a fan, a multi-phase generator as claimed in one of claims 1 to 8, a PWM rectifier and a cascaded grid-connected inverter, the fan and multiple The phase generators are connected, and each phase generator is connected to a PWM rectifier to realize unit voltage stabilization, and then through the H-bridge unit cascaded grid-connected inverter to realize grid-connected power generation with a 6kV-10kV high-voltage grid.

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