A portable multi-stage induction coil transmitting device and control method

Abstract

The present application discloses a portable multi-stage induction coil transmitter and control method, the control method comprising: increasing the battery voltage to the voltage required for transmission through a DC-DC switch boost circuit; modulating the voltage required for transmission through a DC-AC voltage modulation circuit to obtain a sinusoidal AC voltage of a preset frequency; after applying the sinusoidal AC voltage of the preset frequency to the transmitting coil, using the sensor signal of the front end of each coil to detect the projectile to control the on-off of the IGBT to achieve the best match between the projectile position and the coil working state. The induction coil transmitter is portable and miniaturized by using a battery DC power supply, and the output voltage of the DC-DC boost circuit, the output voltage frequency of the DC-AC voltage modulation circuit, and the working selection of each coil are adjusted by controlling the IGBT to output a PWM switch signal to achieve controllable projectile speed, and the projectile position is matched with the working coil by using the IGBT to control the transmitting circuit.

Description

Technical Field

[0001] The invention belongs to the technical field of electromagnetic induction transmitters, and in particular relates to a portable multi-stage induction coil transmitting device and a control method. Background Art

[0002] Electromagnetic launch technology is a launch technology that converts electrical energy into kinetic energy. It has immeasurable application prospects in scientific research, industry, aerospace and military fields. However, in the existing technology, electromagnetic guns use the interaction between magnetic field and magnetizing current to accelerate projectiles. It is difficult to achieve full acceleration in the coil by magnetic resistance launch. The projectile is only subjected to tension at a small part of the coil entrance when entering the coil, not the entire projectile. According to the principle of minimum magnetic resistance, the tension is zero after the projectile enters the coil, but it will be decelerated by reverse tension when leaving the coil. The magnetic resistance launcher has many disadvantages such as low launch efficiency and limited acceleration.

[0003] Secondly, electromagnetic transmission currently mainly relies on capacitor discharge to generate pulse current to power the transmitter. Capacitors have a certain weight and volume, and their portability and miniaturization are limited by objective conditions, and the energy utilization rate of capacitor discharge is low. Summary of the invention

[0004] In order to solve the above technical problems, this application proposes the following technical solutions:

[0005] In a first aspect, an embodiment of the present application provides a control method for a portable multi-stage induction coil transmitting device, comprising:

[0006] The battery voltage is increased to the voltage required for transmission through a DC-DC switching boost circuit;

[0007] The voltage required for transmission is modulated by a DC-AC voltage modulation circuit to obtain a sinusoidal AC voltage of a preset frequency;

[0008] After the sinusoidal AC voltage of the preset frequency is applied to the transmitting coil, the sensor signal of the projectile detected at the front end of each coil is used to control the on and off of the IGBT to achieve the best matching between the projectile position and the working state of the coil.

[0009] In a possible implementation, the step of increasing the battery voltage to a voltage required for transmission through a DC-DC switch boost circuit includes:

[0010] Using a controller to control the switching of the IGBT in the DC-DC switching boost circuit;

[0011] The battery voltage is increased to the voltage required for transmission by controlling the switching frequency of the IGBT.

[0012] In a possible implementation, the calculation formula for increasing the battery voltage to the voltage required for emission by controlling the switching frequency of the IGBT is:

[0013] ;

[0014] in, Input voltage for the battery, is the boost output voltage, is the duty cycle.

[0015] In a possible implementation, the step of modulating the voltage required for transmission by a DC-AC voltage modulation circuit to obtain a sinusoidal AC voltage of a preset frequency includes:

[0016] The controller output signal is used to control the switching of the IGBT;

[0017] The DC voltage output by the DC-DC switching boost circuit is subjected to PWM modulation to obtain a sinusoidal AC voltage of a preset frequency.

[0018] In a possible implementation, the DC voltage output by the DC-DC switching boost circuit is subjected to PWM modulation, and the calculation formula for obtaining a sinusoidal AC voltage of a preset frequency is:

[0019] ;

[0020] in, is the final output voltage, is the current frequency, k It is the ratio of the inverter voltage amplitude of the DC-AC output to the DC voltage value of the DC-DC output.

[0021] In a possible implementation, after the sinusoidal AC voltage of the preset frequency is applied to the transmitting coil, the sensor signal of the projectile detected at the front end of each coil is used to control the on and off of the IGBT to achieve the best match between the projectile position and the coil working state, including:

[0022] The electromagnetic energy is calculated using the principle of conservation of energy. The calculation formula for electromagnetic energy is:

[0023] ;

[0024] in, ; ; is the magnetic flux, is the transmitting coil reluctance, is the coil current, is the loop resistance, is the coil inductance, For the projectile inductance, is the mutual inductance between the projectile and the coil, is the inductive coupling coefficient, is the number of coil turns, is an imaginary unit;

[0025] The force on the projectile is calculated based on the electromagnetic energy obtained;

[0026] The sensor signals of the projectiles detected at the front end of each coil are used to control the on and off of the IGBT to achieve the best match between the projectile position and the working state of the coil.

[0027] In a possible implementation, the formula for calculating the force on the projectile based on the acquired electromagnetic energy is:

[0028]

[0029]

[0030] .

[0031] In a second aspect, an embodiment of the present application provides a portable multi-stage induction coil transmitting device, including: a battery pack, a DC-DC switch boost circuit, a DC-AC voltage modulation circuit, a controller, an IGBT control circuit and a transmitting coil;

[0032] The battery pack is used to provide transmission energy;

[0033] The DC-DC switch boost circuit is used to increase the battery pack voltage to the transmission voltage;

[0034] The DC-AC voltage modulation circuit is used to modulate the DC transmission voltage into a sinusoidal AC voltage of a preset frequency;

[0035] The controller outputs a PWM signal according to transmission needs to control the switching of the DC-DC switching boost circuit, the DC-AC voltage modulation circuit and the IGBT of the control circuit.

[0036] In a possible implementation, a projectile is disposed in the transmitting coil, and the projectile is made of a non-magnetic material.

[0037] Compared with the prior art, the beneficial effects of this application are:

[0038] This application uses a battery DC power supply to realize the portable and miniaturized induction coil transmitter. By controlling the IGBT to output a PWM switch signal, the DC-DC boost circuit output voltage and the DC-AC voltage modulation circuit output voltage frequency and the working selection of each level of coils are adjusted to achieve controllable projectile speed. At the same time, compared with the magnetic resistance type transmitter, the projectile is continuously accelerated by the overall force in the coil without reverse pulling force. The IGBT is used to control the transmitting circuit to achieve the matching of the projectile position and the working coil, avoiding the influence of the residual coil inductance energy storage on the power supply caused by the sudden cutting off of the coil at this level after the projectile is fired. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 A schematic diagram of the structure of a portable multi-stage induction coil transmitting device provided in an embodiment of the present application;

[0040] Figure 2 A schematic flow chart of a control method of a portable multi-stage induction coil transmitting device provided in an embodiment of the present application;

[0041] Figure 3 A circuit schematic diagram of a DC-DC switching boost circuit provided in an embodiment of the present application;

[0042] Figure 4 A topology diagram of the transmitter circuit provided in an embodiment of the present application. DETAILED DESCRIPTION

[0043] The present solution is described below in conjunction with the accompanying drawings and specific implementation methods.

[0044] Figure 1 A schematic diagram of the structure of a portable multi-stage induction coil transmitting device provided in an embodiment of the present application, see Figure 1 The portable multi-stage induction coil transmitting device in this embodiment includes: a battery pack, a DC-DC switch boost circuit, a DC-AC voltage modulation circuit, a controller, an IGBT control circuit and a transmitting coil. The battery pack is used to provide transmitting energy, the DC-DC switch boost circuit is used to increase the battery pack voltage to the voltage required for transmitting, the DC-AC voltage modulation circuit is used to modulate the DC transmitting voltage into a sinusoidal AC voltage of a preset frequency, the controller outputs a PWM signal according to the transmitting needs to switch the DC-DC switch boost circuit, the DC-AC voltage modulation circuit and the IGBT of the control circuit, the control circuit includes a switching coil IGBT switch, and a projectile is arranged in the transmitting coil, the projectile is a non-magnetic material, aluminum or copper can be selected, and is a cylinder.

[0045] Figure 2A schematic diagram of a control method for a portable multi-stage induction coil transmitting device provided in an embodiment of the present application. A control method for a portable multi-stage induction coil transmitting device in this embodiment includes:

[0046] S101, the battery voltage is increased to the voltage required for transmission through a DC-DC switching boost circuit.

[0047] In order to realize the portable and miniaturized induction coil transmitter, a battery DC power supply is used in this embodiment. Since the battery voltage is relatively low, the controller is used to control the switching of the IGBT in the DC-DC switching boost circuit, and the battery voltage is increased to the voltage required for transmission by controlling the switching frequency of the IGBT. Figure 3 , a circuit schematic diagram of a DC-DC switching boost circuit provided in an embodiment of the present application, using a controller to control the on-time of an IGBT in the DC-DC switching boost circuit With deadline To control, the duty cycle is calculated according to the on-time and off-time of the IGBT. The calculation formula of the duty cycle is:

[0048] ;in, ;

[0049] The formula for calculating the output voltage after boost is:

[0050] ;

[0051] in, Input voltage for the battery, is the boost output voltage, is the duty cycle.

[0052] S102, modulating the voltage required for transmission through a DC-AC voltage modulation circuit to obtain a sinusoidal AC voltage of a preset frequency.

[0053] In this embodiment, the DC-AC voltage modulation circuit uses the digital quantity output by the controller to boost the DC output voltage. PWM modulation is performed to obtain a sinusoidal AC voltage. The calculation formula for the output sinusoidal AC voltage is:

[0054] ;

[0055] in, is the final output voltage, is the current frequency, k It is the ratio of the inverter voltage amplitude of the DC-AC output to the DC voltage value of the DC-DC output.

[0056] S103, after applying a sinusoidal AC voltage of a preset frequency to the transmitting coil, the sensor signal of the projectile detected at the front end of each coil is used to control the on and off of the IGBT to achieve the best match between the projectile position and the coil working state.

[0057] See also Figure 4 , the transmitter circuit topology diagram provided in the embodiment of the present application, where P is a projectile, L is a transmitting coil, and D is a unidirectional diode. The battery voltage is boosted by the DC-DC module and modulated by the DC-AC module to provide voltage to the coil , the controller outputs PWM signals to control the DC-DC and DC-AC switches to achieve boost and frequency modulation. When the first-stage coil is launched, the projectile needs to be placed inside the coil, and IGBT1-1 and IGBT1-2 are closed. When the projectile is ejected from the first-stage coil, IGBT1-1 and IGBT1-2 are turned on to cut off the influence of the inductor energy storage in the transmitting coil on the power supply circuit. At the same time, the energy stored in the inductor is suddenly cut off and consumed in the form of current through the diode D to form a closed loop. At the same time, IGBT2-1 and IGBT2-2 are closed to achieve continuous acceleration of the projectile, and the cycle is carried out.

[0058] In this embodiment, considering that the projectile is a non-magnetic material, the magnetizing current can be ignored, and the eddy current field control equation is:

[0059] ;

[0060] ;

[0061] ;

[0062] in, is the magnetic permeability in vacuum, is the coil current density, is the conductivity, is the projectile displacement, is the vector magnetic potential, is the projectile velocity, is the Laplace operator.

[0063] The electromagnetic energy is calculated using the principle of conservation of energy. The calculation formula for electromagnetic energy is:

[0064] ;

[0065] in, ; ; is the magnetic flux, is the transmitting coil reluctance, is the coil current, is the loop resistance, is the coil inductance, For the projectile inductance, is the mutual inductance between the projectile and the coil, is the inductive coupling coefficient, is the number of coil turns, Is an imaginary unit.

[0066] The force on the projectile is calculated based on the electromagnetic energy obtained. The formula for calculating the force on the projectile based on the electromagnetic energy obtained is:

[0067]

[0068]

[0069] .

[0070] The speed of the projectile is changed by adjusting the current frequency and duty cycle, and the sensor signal of the projectile detected at the front end of each level of coil is used to control the on and off of the IGBT to achieve the best match between the projectile position and the working state of the coil.

[0071] In the embodiments of the present application, "multiple" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent the existence of A alone, the existence of A and B at the same time, and the existence of B alone. A and B can be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship.

[0072] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0073] The above is only a specific implementation of the present application. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. The protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A control method for a portable multi-stage induction coil transmitting device, characterized in that: include: The battery voltage is increased to the voltage required for transmission through a DC-DC switching boost circuit; The voltage required for transmission is modulated by a DC-AC voltage modulation circuit to obtain a sinusoidal AC voltage of a preset frequency; The sinusoidal AC voltage of the preset frequency is applied to the transmitting coil after passing through the IGBT control circuit, and the on-off of the IGBT in the IGBT control circuit is controlled by the sensor signal of the front end of each coil to detect the projectile, so as to achieve the best matching between the projectile position and the working state of the coil, including: The electromagnetic energy is calculated using the principle of conservation of energy. The calculation formula for electromagnetic energy is: ； in, ; ; is the magnetic flux, is the transmitting coil reluctance, is the coil current, is the loop resistance, is the final output voltage, is the current frequency, is the coil inductance, For the projectile inductance, is the mutual inductance between the projectile and the coil, is the inductive coupling coefficient, is the number of coil turns, is an imaginary unit; The force on the projectile is calculated based on the acquired electromagnetic energy; the formula for calculating the force on the projectile based on the acquired electromagnetic energy is: ； in, is the duty cycle, Enter the voltage for the battery.

2. The control method of the portable multi-stage induction coil transmitting device according to claim 1, characterized in that: The step of increasing the battery voltage to the voltage required for transmission through a DC-DC switch boost circuit comprises: Using a controller to control the switching of the IGBT in the DC-DC switching boost circuit; The battery voltage is increased to the voltage required for transmission by controlling the switching frequency of the IGBT.

3. The control method of the portable multi-stage induction coil transmitting device according to claim 2, characterized in that: The calculation formula for increasing the battery voltage to the voltage required for emission by controlling the switching frequency of the IGBT is: ； in, Input voltage for the battery, is the boost output voltage, is the duty cycle.

4. The control method of the portable multi-stage induction coil transmitting device according to claim 1, characterized in that: The step of modulating the voltage required for transmission by a DC-AC voltage modulation circuit to obtain a sinusoidal AC voltage of a preset frequency includes: The controller output signal is used to control the switching of the IGBT; The DC voltage output by the DC-DC switching boost circuit is subjected to PWM modulation to obtain a sinusoidal AC voltage of a preset frequency.

5. The control method of the portable multi-stage induction coil transmitting device according to claim 1, characterized in that: The DC voltage output by the DC-DC switching boost circuit is PWM modulated to obtain a sinusoidal AC voltage of a preset frequency. The calculation formula is: ； in, is the final output voltage, is the current frequency, k It is the ratio of the inverter voltage amplitude of the DC-AC output to the DC voltage value of the DC-DC output.

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