Generator and power generation system using same

Abstract

A power generator that generates power using electromagnetic induction of a plurality of permanent magnets provided in a rotor and a plurality of coils provided in a stator disposed concentrically with the rotor, the power generator being provided with: a rotational position detection unit 11 that detects the rotational position of the rotor; first switching elements (Tr11, Tr12) provided on a first path through which an induced current generated in the coil (32) flows; and a control unit (12) that performs control such that the first switching elements (Tr11, Tr12) are turned off during a first period, which is at least a part of a period in which electromagnetic resistance is generated in the opposite direction of the rotation direction of the rotor due to the flow of the induced current, and the first switching elements (Tr11, Tr12) are turned on during a non-first period, which is at least a part of a period in which electromagnetic resistance is generated in the opposite direction of the rotation direction of the rotor. The induction current in the induction direction of the electromagnetic resistance does not flow on the first path in a first period in which the electromagnetic resistance is generated when the induction current flows.

Description

Technical Field

[0001] The present invention relates to a generator and a power generation system using the same, and is particularly suitable for a generator that generates voltage by rotating a rotor and a power generation system using the same. The generator includes a cylindrical rotor with multiple permanent magnets and a cylindrical stator with multiple coils and arranged concentrically with the rotor. Background Art

[0002] In the past, there is a known generator that uses electromagnetic induction to convert the energy of a magnet into electrical energy to generate electricity, wherein electromagnetic induction means that when the magnetic flux passing through a coil changes, an electromotive force (voltage) is generated in the coil, thereby causing current to flow in the coil. For example, there is a known generator that includes a cylindrical rotor (rotor) in which permanent magnets of N poles and permanent magnets of S poles are alternately arranged in a ring shape, and a cylindrical stator (stator) having a plurality of coils at a position opposite to the permanent magnets and arranged concentrically with the rotor, and the voltage is generated by rotating the rotor to change the distance between the permanent magnets and the coils.

[0003] In this generator, when the N-pole magnet of the rotor to which a rotational force is applied approaches the coil, the magnetic flux passing through the coil increases. Thus, a new magnetic flux is generated in the direction in which the magnetic flux in the coil does not increase, and an induced current flows. In addition, when the N-pole magnet moves away from the coil, the magnetic flux passing through the coil decreases. Thus, a new magnetic flux is generated in the direction in which the magnetic flux in the coil does not decrease, and an induced current flows. The direction of the induced current flowing in the coil follows Lenz's law, and the direction of the induced current is opposite when the N-pole magnet approaches the coil and when it moves away from the coil. The direction of the induced current generated when the S-pole magnet approaches the coil and when it moves away from the coil is opposite to that of the N-pole.

[0004] However, if the permanent magnet is displaced by the rotation of the rotor, and an induced current is generated in the coil when the permanent magnet passes directly above the coil of the stator arranged at a position opposite to the permanent magnet, the coil becomes an electromagnet with a magnetic pole in the opposite direction to the permanent magnet, and when the permanent magnet moves away from the coil, the rotation direction of the permanent magnet is braked. Therefore, this forms an electromagnetic resistance in the opposite direction of rotation, resulting in a decrease in the power generation efficiency of the generator.

[0005] In addition, there is known a generator in which a circuit having a switching element, a drive circuit for turning the switching element on and off, and a position detection circuit are connected to the winding of the generator, and the position detection circuit detects the relative position of the stator and the rotor and outputs it to the drive circuit, so that the phase of the current flowing in the winding can maintain the device in an efficient operating state (for example, refer to patent document 1).

[0006] In the generator described in Patent Document 1, the drive circuit sequentially turns on and off the switch elements connected to the three-phase coils according to the signal from the position detection circuit, thereby making the current flowing in the three-phase coils basically on the q-axis (flowing in the phase of θ = 0), and the torque generated in the magnetic resistance torque and the induced electromotive force (Fleming's left-hand rule) are almost maximum when θ = 0. However, this cannot suppress the generation of electromagnetic resistance itself.

[0007] Patent Document 1: Japanese Patent Application Publication No. 2003-245000 Summary of the invention Problems to be solved by the invention

[0008] The present invention is completed to solve such problems, and its purpose is to provide a generator, which includes a cylindrical rotor having a plurality of permanent magnets, and a cylindrical stator having a plurality of coils and arranged concentrically with the rotor, and generates voltage by rotating the rotor. The generator can reduce the electromagnetic resistance generated to prevent the rotation of the rotor. Technical solutions to the problem

[0009] In order to solve the above problems, the generator of the present invention includes a cylindrical rotor having a plurality of permanent magnets and a cylindrical stator having a plurality of coils and arranged concentrically with the rotor, and generates voltage by rotating the rotor, and has the following structure. That is, the generator includes a rotation position detection unit for detecting the rotation position of the rotor; and a first switch element provided on a first path where an induced current generated in the coil flows according to a change in the distance between the permanent magnet and the coil; and a control unit for controlling the first switch element to be turned off during at least a portion of the period during which the induced current flows and causes electromagnetic resistance opposite to the rotation direction of the rotor, i.e., a first period, based on the rotation position of the rotor detected by the rotation position detection unit, and to turn on the first switch element outside the first period. Effects of the Invention

[0010] According to the present invention having the above configuration, in the first period of at least a part of the period in which electromagnetic resistance is generated when the induced current flows, the first switching element provided on the first path in which the induced current flows is turned off, so that the induced current in the direction inducing the electromagnetic resistance no longer flows. Thus, the electromagnetic resistance generated to prevent the rotation of the rotor can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 1 is a diagram showing an example of the overall configuration of a power generation system according to this embodiment. FIG. 2 is a diagram showing a configuration example of a generator (excluding a circuit portion) according to the present embodiment. Figure 3 It is a diagram showing a configuration example of a circuit portion of a generator according to this embodiment. Figure 4 FIG. 1 is a diagram showing a first path through which the induced current flows. Figure 5 A diagram showing a second path through which a current flows in a direction opposite to the direction in which the induced current flows. Figure 6 1 is a diagram showing an example of a control signal output by a control unit and a voltage waveform generated at both ends of a coil. Figure 7 This is a diagram showing another example of the control signal output by the control unit and the voltage waveform generated at both ends of the coil. Figure 8 This is a diagram showing another example of the control signal output by the control unit and the voltage waveform generated at both ends of the coil. Fig. 9 It is a diagram showing another configuration example of the circuit portion of the generator according to the present embodiment. Fig.10 FIG. 2 is a diagram showing another overall configuration example of the power generation system according to the present embodiment. Fig.11 It is a diagram showing another configuration example of the circuit portion of the generator according to the present embodiment. Fig.12 It is a diagram showing an example of the configuration of the control unit according to the present embodiment. Specific embodiments

[0012] Hereinafter, one embodiment of the present invention will be described with reference to the accompanying drawings. Figure 1 FIG. 2 is a diagram schematically showing an example of the overall configuration of a power generation system according to this embodiment. Figure 1 As shown, the power generation system 100 of the present embodiment is configured to include a generator 10 and an engine 20 , a DC-AC inverter 30 , and a battery 40 , the rotors of which are supported on the same rotating shaft 50 .

[0013] The generator 10 includes a cylindrical rotor having a plurality of permanent magnets and a cylindrical stator having a plurality of coils and the rotor is arranged concentrically. When the rotor rotates, a voltage is generated through electromagnetic induction between the permanent magnets and the coils. The engine 20 is a component that applies a rotational driving force to the rotor of the generator 10, such as an electric motor. The battery 40 is a working power supply for the engine 20. The DC-AC inverter 30 converts the DC voltage generated by the discharge of the battery 40 into an AC voltage, and applies the AC voltage to the engine 20.

[0014] The power generation system 100 of this embodiment drives the engine 20 to rotate its rotor, and rotates the rotor of the generator 10 via the rotating shaft 50 fixed to the rotor, thereby generating electricity by electromagnetic induction between multiple permanent magnets arranged on the rotor and multiple coils arranged on the stator.

[0015] Fig. 2 is a diagram showing a configuration example (excluding the circuit portion) of the generator 10. As shown in Fig. 2(a), the generator 10 of this embodiment includes a cylindrical rotor 2 mounted on a rotating shaft 50 rotatably supported on a housing 1, and a cylindrical stator 3 fixed to the housing 1 and arranged inside the rotor 2 concentrically with the rotor 2.

[0016] As shown in FIG. 2( a), the rotor 2 has a plurality of permanent magnets 21 arranged in a ring shape in the direction of rotation. The N poles and S poles of the plurality of permanent magnets 21 are alternately arranged in close contact. Each permanent magnet 21 is fixed at an equidistant angle relative to the rotation center of the rotor 2, and is magnetized with parallel anisotropy of each polarity in the diameter direction. The number of permanent magnets 21 is an even number greater than or equal to the number of teeth 31 described later (in this embodiment, 12, the same number as the teeth 31, are used).

[0017] As shown in Fig. 2(a), the stator 3 is arranged opposite to the surface of the permanent magnet 21, and has a plurality of teeth 31 formed integrally with a cylindrical yoke (yoke iron) and protrudingly arranged along the outer peripheral surface. In the example of Fig. 2(a), the 12 teeth 31 are arranged radially at intervals of 30° relative to the rotation center of the rotor 2.

[0018] As shown in Fig. 2(b), a coil 32 is wound around each tooth 31 along its outer circumference. The tooth 31 is a rectangular prism with a circumferential cross section, and is formed into a plate-like shape with a short side of about 1 to 3 mm. A thin plate-shaped magnetic flux leakage prevention cover 33 is installed at the end opposite to the surface of the permanent magnet 21 to prevent magnetic flux leakage from the outside of the tooth 31. The magnetic flux leakage prevention cover 33 is made of, for example, stainless steel such as a non-magnetic body.

[0019] Coils 32 are continuously connected to three groups of four teeth 31 every three teeth 31 in order to generate current of the same phase when receiving the magnetic flux from the permanent magnet 21 of the rotor 2. Thus, three-phase alternating current of U phase, V phase, and W phase is generated. Each coil 32 is preferably a high inductance coil, but is not particularly limited thereto. The stator 3 is a known structure that can collect three-phase alternating current from the output portion of the coil 32 of each tooth 31 of U phase, V phase, and W phase.

[0020] Figure 3 1 is a diagram showing an example of the configuration of the circuit portion of the generator 10. Figure 3 As shown in FIG. 1 , the circuit structure of the generator 10 of this embodiment includes a rotation position detection unit 11, a control unit 12, and a level shifter 13. -1 ,13 -2 , inverter 14, first switching element Tr 11 ,Tr 12 , the second switching element Tr 21 ,Tr 22and power supply Vcc. Figure 3 In the configuration shown, a common circuit common to the U phase, V phase, and W phase is used for the rotation position detection unit 11 and the control unit 12. The other configurations are configuration examples related to one of the three phases, and the same configuration is provided for the other two phases.

[0021] The rotation position detection unit 11 has a pulse sensor, and uses the pulse sensor to detect the rotation position of the rotor 2. The pulse sensor is composed of, for example, a magnetic sensor or an optical sensor. The pulse sensor is composed of, for example, a passive element mounted on the rotor 2 of the generator 10 and an active element mounted on the stator 3 in pair. The installation position of the active element (hereinafter referred to as the detection position) is the relative position when the rotor 2 rotates so that the passive element reaches a predetermined rotation position.

[0022] For example, in the case where the pulse sensor is composed of a magnetic sensor, the pulse sensor uses a passive element to detect the size of the magnetic field emitted by the detection magnet as an active element installed at the detection position of the stator 3, and outputs a pulse signal when the detected magnetic field reaches the maximum (when the passive element of the rotor 2 is closest to the active element of the stator 3). In the case where the passive element of the rotor 2 and the active element of the stator 3 are respectively provided, the pulse sensor detects the rotational position when the passive element installed on the rotor 2 is closest to the detection position where the active element of the stator 3 is provided each time the rotor 2 rotates once, and outputs a pulse signal. The same is true for the case where the pulse sensor is composed of an optical sensor.

[0023] In addition, multiple passive elements may be provided for the rotor 2. In this case, the rotor 2 outputs a pulse signal multiple times each time it rotates. It is preferred to provide multiple passive elements at equal intervals in the rotation direction of the rotor 2 so that multiple pulse signals are output at equal time intervals in a stable state where the rotor 2 rotates at a constant speed. Conversely, the passive element mounted on the rotor 2 may be set to one, and multiple active elements may be provided for the stator 3.

[0024] Alternatively, a pulse sensor may be mounted on the rotor (not shown) of the engine 20 or the rotating shaft 50 instead of being provided on the rotor 2 of the generator 10. Alternatively, an active element may be provided on the rotor and a passive element may be provided on the stator.

[0025] The first switching element Tr 11 ,Tr 12 The first path where an induced current generated in the coil 32 flows in response to a change in the distance between the permanent magnet 21 of the rotor 2 and the coil 32 of the stator 3 is provided, and is turned on and off according to the control of the control unit 12 . Figure 4 is a diagram showing the first path. Figure 4As shown by the thick dotted line in FIG, the first path is through the power supply Vcc, the first switch element Tr 11 ,Tr 12 and the path of the coil 32. The induced current generated in the coil 32 by electromagnetic induction is output from both ends of the coil 32 to the load RL.

[0026] The second switching element Tr 21 ,Tr 22 A second path is provided for passing a current in a direction opposite to the direction in which the induced current flows through the coil 32 , and is turned on and off according to the control of the control unit 12 . Figure 5 is a diagram showing the second path. Figure 5 As shown by the thick dotted line in FIG, the second path is through the power supply Vcc, the second switch element Tr 21 ,Tr 22 and the path of the coil 32. At this time, the current flowing in the coil 32 is output from both ends of the coil 32 to the load RL.

[0027] The first switching element Tr 11 ,Tr 12 and the second switching element Tr 21 ,Tr 22 (Hereinafter, these four elements are sometimes combined and referred to as "switching element Tr"), for example, a transistor such as a MOSFET, is turned on or off according to a signal input to its gate terminal. 11 ,Tr 21 N-channel MOSFET, the two switching elements Tr on the lower side 12 ,Tr 22 is a P-channel MOSFET. Figure 3 As shown, an H-bridge circuit is formed by these four switching elements Tr.

[0028] The control unit 12 outputs a control signal composed of, for example, a rectangular wave. The control signal is passed through the level shifter 13 -1 , 13 -2 The inverter 14 is input to the gate terminal of the switching element Tr. During the period when the control unit 12 outputs the control signal of Low, the first switching element Tr 11 ,Tr 12 The second switching element Tr is turned on. 21 ,Tr 22 On the other hand, during the period when the control unit 12 outputs the control signal Hi, the first switching element Tr 11 ,Tr 12 The second switching element Tr is turned off. 21 ,Tr 22 Connected.

[0029] In addition, the control unit 12 may be composed of any of hardware, DSP (Digital Signal Processor) and software. For example, in the case of being composed of software, the control unit 12 is actually composed of a microcomputer having a CPU, RAM, ROM, etc. of a computer, and is implemented by running a program stored in a storage medium such as RAM, ROM, hard disk or semiconductor memory.

[0030] The control unit 12 controls so that the first switching element Tr is turned off in a first period of at least a part of a period in which electromagnetic resistance is generated in the direction opposite to the rotation direction of the rotor 2 due to the flow of the induced current in the coil 32, according to the rotation position of the rotor 2 detected by the rotation position detection unit 11. 11 ,Tr 12 , in the non-first period, the first switching element Tr is turned on 11 ,Tr 12 In addition, the control unit 12 performs control so that when the first switching element Tr is turned off, 11 ,Tr 12 The second switching element Tr is turned on for at least a portion of the first period of time. 21 ,Tr 22 , in the non-second period, the second switch element Tr is turned off 21 ,Tr 22 .

[0031] In the present embodiment, the period in which the electromagnetic resistance is generated in the direction opposite to the rotation direction of the rotor 2 is the period in which the permanent magnet 21 of the N pole is far away from the coil 32 and the period in which the permanent magnet 21 of the S pole is far away from the coil 32. That is, the period from the moment when the permanent magnet 21 of the N pole is closest to the coil 32 to the moment when the permanent magnet 21 of the N pole is far away from the coil 32, and the period from the moment when the permanent magnet 21 of the S pole is closest to the coil 32 to the moment when the permanent magnet 21 of the S pole is far away from the coil 32.

[0032] For example, when the pulse sensor of the rotation position detection unit 11 is composed of a combination of an active element and a passive element, by setting the active element and the passive element of the pulse sensor at positions where the relative positional relationship between the permanent magnet 21 and the coil 32 can be detected, the rotation position detection unit 11 can detect the time when the permanent magnet 21 and the coil 32 are closest to each other. In addition, based on the relationship between the rotation speed of the rotor 2 in a stable state and the size of the permanent magnet 21, if the rotation time required from the time when the permanent magnet 21 and the coil 32 are closest to each other to the time when they are farthest from each other is calculated in advance, then based on the time detected by the rotation position detection unit 11 and the rotation time calculated in advance, the time when the permanent magnet 21 and the coil 32 are farthest from each other can also be determined.

[0033] In addition, as shown in Figure 2, when the passive elements of the two pulse sensors are arranged on the rotor 2 at an interval of 30° while forming the generator 10, the rotation position detection unit 11 can respectively detect the moment when the permanent magnet 21 is closest to the coil 32 and the moment when the permanent magnet 21 is farthest from the coil 32.

[0034] In this embodiment, the first time period and the second time period are the same time period. That is, the entire first time period is the second time period. 11 ,Tr 12 When turned on, the second switching element Tr 21 ,Tr 22 Turn off, the first switch element Tr 11 ,Tr 12 When turned off, the second switch element Tr 21 ,Tr 22 Connected.

[0035] The control unit 12 can also monitor whether the rotor 2 has reached a stable state of constant speed rotation based on the pulse signal of the detection result sequentially output by the rotation position detection unit 11 corresponding to the rotation of the rotor 2, and control the on and off of the switching element Tr after detecting that the stable state has been reached. In this way, the first time period (= second time period) can be detected more accurately, and the on and off of the switching element Tr can be controlled more accurately.

[0036] Figure 6 is a control signal ( Figure 6 (b)) and the voltage waveform generated at both ends of the coil 32 ( Figure 6 (a)) of the graph. Figure 6 The period in which the electromagnetic resistance is generated in the direction opposite to the rotation direction of the rotor 2 (the period in which the coil 32 is away from the permanent magnet 21), the first switching element Tr is turned off, and the 11 ,Tr 12 The first period of time and the second switching element Tr is turned on 21 ,Tr 22 An example of a situation where all the second periods are the same. In addition, Figure 6 (c) shows, for reference, a voltage waveform of a conventional type in which the switching element Tr is not provided.

[0037] exist Figure 6 In the embodiment, the period T1 is the period when the permanent magnet 21 of the N pole approaches the coil 32. The period T2 is the period when the permanent magnet 21 of the N pole is far away from the coil 32. The period T3 is the period when the permanent magnet 21 of the S pole approaches the coil 32. The period T4 is the period when the permanent magnet 21 of the S pole is far away from the coil 32. Figure 6 As shown in (b), the control unit 12 outputs a rectangular wave control signal which is Low in the periods T1 and T3 and is Hi in the periods T2 and T4.

[0038] Therefore, in the time periods T1 and T3, the first switching element Tr 11 ,Tr 12 The second switching element Tr is turned on. 21 ,Tr 22 The induced current generated in the coil 32 flows along Figure 4 At this time, the induced current generated in the coil 32 by electromagnetic induction is output from both ends of the coil 32 to the load RL.

[0039] In addition, during the time periods T2 and T4 (= the first time period and the second time period), the first switching element Tr 11 ,Tr 12 The second switching element Tr is turned off. 21 ,Tr 22 When the power supply Vcc is turned on, the current flows along Figure 5 At this time, current is output from both ends of the coil 32 to the load RL. Figure 6 (a) with Figure 6 (c) By comparison, it can be seen that in the time periods T2 and T4, the induced current does not flow. Generally, the current is in a state of flowing in the direction opposite to the flow direction of the induced current.

[0040] According to the generator 10 of the present embodiment configured as described above, in the period (= the first period of the period T2, T4) when the induced current flows through the coil 32 and generates electromagnetic resistance, the first switching element Tr provided on the first path of the induced current is turned off. 11 ,Tr 12 , the induced current in the direction of inducing electromagnetic resistance will no longer flow. Thus, the electromagnetic resistance generated to prevent the rotation of the rotor 2 can be reduced.

[0041] In addition, in the generator 10 of the present embodiment, in the second period (=period T2, T4) which is the same as the first period, by turning on the second switching element Tr provided on the second path 21 ,Tr 22 , so that the current in the opposite direction to the induced current flows in the coil 32. Therefore, according to Fleming's left-hand rule, the electromagnetic force generated by the current in the opposite direction is consistent with the rotation direction of the rotor 2, thereby playing a role in assisting the rotation of the rotor 2.

[0042] In addition, Figure 6 , the period of time during which the electromagnetic resistance is generated in the direction opposite to the rotation direction of the rotor 2 and the period during which the first switching element Tr is turned off are shown. 11 ,Tr 12 This is an example of the case where the first time period is the same as the first time period, but is not limited to this. Figure 7The first switching element Tr is turned off. 11 ,Tr 12 Here, the time period from the moment after the specified time after entering the electromagnetic resistance generation period (the moment after the specified time after the permanent magnet 21 is closest to the coil 32) to the moment when the permanent magnet 21 is farthest from the coil 32 is set as the first time period. In addition, the time period from the moment when the permanent magnet 21 is farthest from the coil 32 to the specified time can also be regarded as the first time period.

[0043] In addition, Figure 6 In FIG. 1 , it is shown that when the first switching element Tr is turned off 11 ,Tr 12 The second switching element Tr is turned on in the second period which is the same as the first period 21 ,Tr 22 Examples include, but are not limited to, Figure 8 The second switching element Tr 21 ,Tr 22 In this case, the second switching element Tr can be omitted. 21 ,Tr 22 , and the circuit portion of the generator 10 may be configured as follows Fig. 9 shown.

[0044] In addition, if Figure 5 As shown in FIG. 1 , during the period of time when the current flows through the second path, the first path of the induced current flowing in the coil 32 has not yet been formed, and therefore, the induced current generated according to Fleming's right-hand rule does not flow in the coil 32. That is, only the current from the power supply Vcc flows in the coil 32. However, when the electromotive force generated by the coil 32 exceeds the voltage of the power supply Vcc, the induced current may flow back from the coil 32 to the second switching element Tr. 21 .

[0045] Therefore, the battery 40 can also be charged by the reverse current. Fig.10 4 is a diagram showing a configuration example of a power generation system 100' having a charging function of a battery 40. Fig.11 1 is a diagram showing an example of a circuit configuration of a generator 10' used in a power generation system 100' having a charging function for a battery 40. Fig.10 and Fig.11 In the Figure 1 and Figure 3 Components denoted by the same reference numerals have the same functions, and thus repeated descriptions are omitted here.

[0046] Fig.10 The power generation system 100 'shown has Figure 1In addition to the structure shown, it also includes an AC-DC inverter 60 and a charge-discharge switch 70. Fig.11 The generator 10' shown has Figure 3 In addition to the structure shown, a voltage regulator 15 and a second control unit 16 are also included.

[0047] The second control unit 16 may be composed of any of hardware, DSP, and software. For example, in the case of being composed of software, the second control unit 16 is actually composed of a microcomputer having a CPU, RAM, ROOM, etc. of a computer, and is implemented by running a program stored in a storage medium such as RAM, ROOM, a hard disk, or a semiconductor memory. Here, a structure in which the control unit 12 and the second control unit 16 are separately provided is shown, but a structure in which the control unit 12 has the function of the second control unit 16 may also be adopted.

[0048] The AC-DC inverter 60 converts the AC voltage generated by the generator 10' into a DC voltage. 21 The charge-discharge switch 70 is a switching device for switching the charge or discharge of the battery 40. The switching of the charge-discharge switch 70 is controlled by the second control unit 16 of the generator 10'.

[0049] The voltage regulator 15 is used to make the reverse current flow back to the second switching element Tr 21 The second control unit 16 monitors whether a reverse current flows back to the second switching element Tr in the second period. 21 When a reverse current is detected, the charge / discharge switch 70 is switched from the discharge side to the charge side, thereby controlling the battery 40 to be charged using the reverse current.

[0050] In addition, in the above embodiment, although the time periods (i.e., the first time period and the second time period) during which the control unit 12 outputs the high-level control signal are pre-set, they can also be set to a structure that can be adjusted arbitrarily. Fig.12 As shown, the control unit 12 may include the following components: a waveform shaping circuit 121 for shaping the pulse signal output from the rotation position detection unit 11 into a rectangular wave; a phase shifter 122 for changing the phase of the rectangular wave shaped by the waveform shaping circuit 121; and a ring counter 123 for changing the duty cycle of the rectangular wave shifted by the phase shifter 122. The output signal of the ring counter 123 can be used as a control signal. In this case, the phase change amount generated by the phase shifter 122 and the duty cycle change amount generated by the ring counter 123 can be adjusted by arbitrarily set parameters. In addition, a PWM (pulse width modulation) circuit can also be used instead of the ring counter 123.

[0051] In addition, in the above embodiment, the first time period and the second time period are the same time period, that is, the first time period is the entire second time period, but part of the first time period can also be used as the second time period. In this case, the first switching element Tr needs to be 11 ,Tr 12 The on-off of the second switching element Tr 21 ,Tr 22 The on / off settings are configured as circuit structures that can be controlled separately.

[0052] Furthermore, in the above-described embodiment, although the generator 20 is described as an electric motor, it is not limited thereto and may be, for example, a generator that generates electricity using natural energy, such as wind power, hydroelectric power, or solar power.

[0053] Furthermore, in the above-described embodiment, the battery 40 and the power source Vcc are separately provided, but they may be shared.

[0054] In addition, the above embodiments are only examples of specific implementation of the present invention, but the technical scope of the present invention is not limited thereto. That is, the present invention can be implemented in various ways without departing from its spirit or main features. Reference numerals

[0055] 2 Rotor 3. Stator 10,10' generator 11Rotation position detection unit 12. Control Unit 16 Second control unit 20 Engine 21 permanent magnet 32 coils 40 batteries 70 charge and discharge switch 100,100' power generation system T 11 ,Tr 12 The first switching element T 21 ,Tr 22 The second switching element

Claims

1. A generator comprising a cylindrical rotor having a plurality of permanent magnets and a cylindrical stator having a plurality of coils and arranged concentrically with the rotor, wherein a voltage is generated by rotating the rotor, wherein: include: a rotation position detection unit for detecting a rotation position of the rotor; a first switching element disposed on a first path through which an induced current generated in the coil in response to a change in the distance between the permanent magnet and the coil flows; and A control unit that performs control so that, based on the rotational position of the rotor detected by the rotational position detection unit, the first switching element is turned off in a first time period and is turned on in a time period other than the first time period, wherein the first time period is at least a part of a time period in which electromagnetic resistance is generated in a direction opposite to the rotational direction of the rotor due to the flow of the induced current.

2. The generator according to claim 1, characterized in that: Also includes a second switching element, The second switching element is provided as a second switching element for flowing a current in a direction opposite to that of the induced current to the coil, The control unit performs control so that the second switching element is turned on during a second period of at least a part of the first period in which the first switching element is turned off, and the second switching element is turned off during the rest of the second period.

3. The generator according to claim 2, characterized in that: The first switching element and the second switching element form an H-bridge circuit.

4. The generator according to any one of claims 1 to 3, characterized in that: The control unit monitors whether the rotor has reached a stable state of constant speed rotation based on the signal of the detection result sequentially output by the rotation position detection unit corresponding to the rotation of the rotor, and controls the on and off of the switching element after detecting that the stable state has been reached.

5. A power generation system, characterized in that: include: The generator according to claim 1 or 3; an engine for applying a rotational driving force to the rotor; A battery providing working power for the engine; A charge-discharge switch for switching the charging or discharging of the battery; as well as The second control unit controls the battery to be charged by the reverse current by switching the charge and discharge switch from the discharge side to the charge side when the reverse current flows back to the second switch element during the second period.

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