CN101710778B - Linear generator secondary level and control method - Google Patents

Abstract

The invention relates to a linear generator secondary level and a control method, which belong to the technical field of power electronics. The linear generator secondary level comprises permanent magnets and a backboard, wherein the permanent magnets are fixedly connected with the backboard; the breadth of the permanent magnets is in sine proportion according to an arrangement order, while the arrangement spaces are in cosine arrangement; a divider acquires both the speed value and the induced electromotive force amplified by a multiplier of a linear motor so as to obtain an efficiency ratio by dividing the speed value by the amplified induced electromotive force; and the efficiency ratio is taken as a control variable to control a linear generator. The linear generator secondary level can balance the impact caused by generation current inertia to stabilize a current inverter and a power supply circuit and improve the performance of an entire machine; and at the same time, the control method for balancing induced electromotive force inertia is designed according to the motor form of the uneven secondary level, thereby increasing system performance, simplifying and stabilizing a control system and improving the performance of the entire machine.

Description

A linear generator secondary and its control method

technical field

The invention relates to a linear generator secondary and a control method, belonging to the technical field of power electronics.

Background technique

Worldwide, countries are facing tremendous pressure on energy and environmental protection, so various energy-saving and new energy technologies are developing vigorously. The free piston internal combustion generator is a new type of power that has been gradually developed in the past ten years under such a background of energy and environmental protection. It couples a free-piston internal combustion engine and a linear generator as a whole, and cuts the magnetic force line through the reciprocating linear-moving free-piston assembly to realize the direct conversion of mechanical energy into electrical energy. This type of linear generator has an important component, the linear generator. The generator is required to have two operating modes, namely the motor mode at start-up and the generator mode at power generation. At the same time, as a linear generator, compared with a rotary generator, its flux distribution is in a straight line, and the ends are not connected, resulting in a stronger end effect. Also, because the linear displacement and speed of the piston of the free piston engine used are significantly different from those of the traditional rotary internal combustion engine, its motion displacement curve is an approximate sinusoidal curve, and the acceleration changes greatly, thus bringing greater electrical inertia to the linear generator , its design and control must fully consider the impact and adjustment of electrical inertia, otherwise it will not only seriously affect the performance of the generator, but also affect the conversion of the overall machine performance and the use of the power supply circuit. The original linear generators adopt a uniform secondary arrangement, that is, the permanent magnets or excitation coils are all of the same size and width, and are distributed at equal intervals, so that the working performance of the linear generator is reduced when it is used with a linear internal combustion engine. There are the above defects, which seriously affect the stability and Energy power output. The present invention is aimed at the linear motor part of the linear internal combustion generator, according to the motion law of the primary mover, proposes a non-uniform secondary design and arrangement, and designs a reliable and stable control method for this special form .

The linear generator part of the existing linear internal combustion generator directly adopts the composition of the traditional linear generator, that is, the equal size and uniform secondary are distributed at equal intervals, which does not reflect and exert the characteristics and advantages of the linear internal combustion system. At the same time, because the motion law of the moving piston parts of the linear internal combustion generator is not considered, its reliability and electrical inertia are relatively large, which has a large impact on the power supply circuit and the current inverter, making the system stability and control system reliability poor, seriously affect system performance.

Contents of the invention

The purpose of the present invention is to solve the problem that the existing linear generator is not suitable for the change of reciprocating speed, and propose a secondary and control method of the linear generator.

The purpose of the present invention is achieved through the following technical solutions.

The secondary side of a linear generator of the present invention includes a permanent magnet and a back plate, and the permanent magnet is fixedly connected to the back plate; there are 4 or more permanent magnets, and according to the order of arrangement, the width of the permanent magnets is in a sinusoidal ratio, and the arrangement The gaps are arranged as a cosine.

A secondary control method of a linear generator of the present invention, the method is: the divider obtains the speed value of the linear motor and the induced electromotive force of the linear motor amplified by the gainer, and the divider divides the speed value by the amplified induced electromotive force The value of the efficiency ratio is obtained, and the efficiency ratio is used as a control variable to control the linear generator.

Beneficial effect

The generator power supply circuit of the invention is stable and has high reliability.

Description of drawings

Figure 1 is a schematic diagram of a non-uniform secondary section;

Figure 2 is a structural diagram of the control method.

Detailed ways

The present invention will be further described below in conjunction with drawings and embodiments.

Example

A kind of linear generator secondary of the present invention, as shown in Figure 1, comprises 6 permanent magnets and 1 backboard, and permanent magnet is fixedly connected with backboard; According to arrangement order, the width of permanent magnet is successively 5.0mm, 8.0mm mm, 10.0mm, 10.0mm, 8.0mm, and 5.0mm, the arrangement gaps are 1.9mm, 0.9mm, 0.2mm, 0.9mm, and 1.9mm; the width of the backplane is 20.0mm, and the length is 55.0mm.

A secondary control method of a linear generator of the present invention, the method is: the divider obtains the speed value of the linear motor and the induced electromotive force of the linear motor amplified 20 times by the gainer, and the divider divides the speed value by the amplified The induced electromotive force value obtains the efficiency ratio, and the efficiency ratio is used as a control variable to control the linear motor.

The generator power supply circuit of the invention is stable and has high reliability.

Claims (2)

1. A linear generator secondary, comprising a permanent magnet and a back plate, the permanent magnets are more than 4, and the permanent magnets are fixedly connected to the back plate; it is characterized in that: the width of the permanent magnets is in a sinusoidal ratio according to the arrangement sequence, and the arrangement gap Arranged into a cosine. 2. A control method applied to the linear generator secondary described in claim 1, characterized in that: the divider obtains the speed value of the linear motor and the induced electromotive force of the linear generator amplified by the gainer, and the divider divides the speed The efficiency ratio is obtained by dividing the value by the amplified induced electromotive force value, and the efficiency ratio is used as a control variable to control the linear generator.

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