High-efficiency full-magnetic DC motor control circuit

Abstract

The utility model discloses a high-efficiency full-magnetic direct-current motor control circuit, which comprises a direct-current bus DC +, a direct-current cathode DC-, an IGBT (Insulated Gate Bipolar Transistor) chopping voltage-regulating element Q on the direct-current bus, a three-phase or multi-phase full-bridge control circuit, a full-bridge commutation control circuit consisting of four IGBT switching elements K1 / K2 / K3 / K4 in each phase of full-bridge control circuit, and a phase winding for controlling a motor, and a Buck circuit consisting of a capacitor C1, an inductor L1, a diode D1 and a diode DA is also arranged in front of each phase of full-bridge commutation control circuit. The utility model relates to the technical field of full-magnetic direct current motor control, direct current power supply enters a motor winding after being subjected to high-frequency chopping voltage regulation and voltage stabilization by the Buck circuit, and the current entering the motor winding does not contain high-frequency characteristics, so that the direct current power supply is stable and stable. The high-frequency noise of the motor can be effectively reduced, meanwhile, the capacitor C1 can absorb counter potential energy in the motor winding, the counter potential energy is released into the motor winding again through the Buck circuit, and the mechanical efficiency of the motor is greatly improved through the counter potential energy.

Description

Technical Field

[0001] The utility model relates to the technical field of full-magnetic DC motor control, in particular to a high-efficiency full-magnetic DC motor control circuit. Background Art

[0002] With the advent of the new energy era, research on improving the efficiency of electric motors is a very popular technical field. Based on permanent magnet synchronous motors and brushless DC motors, various research institutions have conducted research on motor structure layout, material selection, cooling methods, frequency conversion control algorithms and other aspects, and have achieved a series of results.

[0003] After years of dedicated research, the inventors of this patent have proposed a fully magnetic DC motor control principle based on the existing brushless DC / permanent magnet synchronous motor drive structure. See invention patent announcement number CN111371350B. This technology has significant advantages such as high power density, simple control, and high efficiency.

[0004] During the research on all-magnetic DC motors, the inventors noticed that there is a very high back EMF in the motor windings. There are two types of back EMF: one is the back EMF generated when the full-bridge controller commutates the winding current, and the current direction is instantly reversed. The back EMF waveform function can be expressed as:

[0005] e=-L(di / dt)

[0006] Where e represents the back EMF, L represents the inductance, and di / dt represents the rate of change of current. This formula shows that the magnitude of the back EMF is proportional to the rate of change of current and the magnitude of the inductance. The greater the rate of change of current and the greater the inductance, the greater the back EMF.

[0007] Another type of back EMF is that during the duration of a waveform, when the rotor rotates, the magnetic bridge of the NS pole sweeps across the motor winding, and the change in the magnetic flux in the winding generates a generating type of back EMF. The magnitude of the back EMF is proportional to the motor speed and is higher than the supply voltage of the winding.

[0008] The waveforms of the two back EMFs are shown in Figure 3 .

[0009] During the generation of this type of back EMF, the anti-back EMF diode DA, located at the front end of the bridge arm, prevents the high voltage from being fed back to the DC bus and thus powering other windings. However, the high back EMF also causes the anti-back EMF diode to cut off, and the DC bus does not power the windings during this period. Summary of the Invention

[0010] In response to the problems of the existing technology, the utility model provides a high-efficiency all-magnetic DC motor control circuit, which solves the problem that the back EMF voltage inside the motor winding is higher than the DC bus voltage, causing the anti-reverse diode to be cut off and unable to supply power to the winding, and greatly improves the efficiency of the motor.

[0011] To achieve the above objectives, the present invention is implemented through the following technical solutions: a high-efficiency full-magnetic DC motor control circuit, including a DC bus DC+, a DC negative pole DC-, an IGBT chopper voltage regulator Q on the DC bus, a three-phase or multi-phase full-bridge control circuit, each phase of the full-bridge control circuit is composed of a full-bridge commutation control circuit consisting of four IGBT switching elements - K1 / K2 / K3 / K4, which controls one phase winding of the motor, and each phase of the full-bridge commutation control circuit also includes a capacitor C1, an inductor L1, a diode D1, and a diode DA, wherein the current entry end of the diode DA is arranged at the input of the IGBT chopper voltage regulator Q on the DC bus DC+. After the output terminal, one end of the inductor L1 is connected to the current output terminal of the diode DA, and the other end of the inductor L1 is connected to the input terminal of the full-bridge control circuit; one end of the capacitor C1 is connected to the input terminal of the full-bridge control circuit, and the other end of the capacitor C1 is connected to the DC negative electrode DC-; the current input terminal of the diode D1 is connected to the DC negative electrode DC-, and the current output terminal of the diode D1 is connected to the current output terminal of the diode DA. The IGBT chopper voltage regulator Q on the DC bus DC+, the inductor L1, the capacitor C1 and the diode D1 form a full-magnetic DC motor single-phase Buck voltage regulator circuit;

[0012] The function of the capacitor C1 is to absorb the high-voltage back electromotive force generated by the full-bridge control circuit when the current passing through the motor winding is commutated, thereby protecting the four IGBT switching elements K1 / K2 / K3 / K4 of the full-bridge control circuit;

[0013] The function of the capacitor C1 is also to absorb the back electromotive force generated by the change of magnetic flux in the motor winding during the operation of the motor;

[0014] The capacitor C1 also functions to stabilize and filter the Buck voltage regulation circuit composed of the IGBT chopper voltage regulation element Q on the DC bus DC+, the inductor L1, the capacitor C1, and the diode D1. Through the filtering effect of the capacitor C1, the high-frequency waveform during the voltage regulation process does not enter the motor winding.

[0015] The capacitor C1 also functions to absorb the back electromotive force generated in the winding during the operation of the motor, thereby reducing the back electromotive force voltage at the front end of the full-bridge control circuit and enabling the diode DA to conduct.

[0016] Preferably, the IGBT chopper voltage regulating element Q on the DC bus DC+ is controlled by a PWM duty cycle signal.

[0017] When the PWM duty cycle control signal of the IGBT chopper voltage regulator Q on the DC bus DC+ is at a high level, the IGBT chopper voltage regulator Q is turned on. When the voltage at the output end of the diode DA is lower than the DC bus voltage, the diode DA is turned on, the inductor L1 is charged, and the current flowing through the inductor L1 increases linearly, providing energy to the load motor winding and charging the capacitor C1 at the same time.

[0018] When the PWM duty cycle control signal of the IGBT chopper voltage regulator element Q on the DC bus DC+ is at a low level, the IGBT chopper voltage regulator element Q is turned off, the inductor L1 forms a discharge loop through the diode D1, and at the same time, the capacitor C1 discharges the inductor L1 through the diode D1, so that the energy absorbed by the capacitor C1 is released into the motor winding to perform work.

[0019] The winding control principle of the full-bridge control circuit can be found in invention patent publication number CN111371350B.

[0020] Since the energy absorbed by capacitor C1 comes not only from the charging of the power supply but also includes the back EMF energy during the operation of the motor, its energy utilization rate is significantly better than that of the traditional BUCK circuit, which significantly improves the efficiency of the motor drive system.

[0021] Beneficial effects

[0022] The utility model discloses a high-efficiency full-magnetic DC motor control circuit, which has the following beneficial effects:

[0023] 1. After the DC power supply undergoes high-frequency voltage regulation and is stabilized by the Buck circuit, it enters the motor winding. The current entering the motor winding does not contain high-frequency characteristics, which can effectively reduce the high-frequency noise of the motor.

[0024] 2. Absorb the back EMF energy in the motor winding and release it back into the motor winding through Buck. The back EMF energy is used to greatly improve the mechanical efficiency of the motor, making the output power of the motor greater than the input power. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a structural diagram of the utility model;

[0026] Figure 2 In the present invention, the capacitor C1 and the full-bridge circuit form a bridge arm energy absorption circuit;

[0027] Figure 3It is the basic waveform of the voltage in the winding A described in the present invention, where V1 is the DC bus supply voltage, V2 is the commutation back EMF voltage, and V3 is the back EMF generated in the motor winding due to the change in magnetic flux, which is proportional to the speed. DETAILED DESCRIPTION

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0029] Embodiment: A high-efficiency full-magnetic DC motor control circuit includes a DC bus DC+, a DC negative pole DC-, an IGBT chopper voltage regulator Q on the DC bus, and a three-phase or multi-phase full-bridge control circuit. Each phase of the full-bridge control circuit is composed of a full-bridge commutation control circuit consisting of four IGBT switching elements - K1 / K2 / K3 / K4, which controls one phase winding of the motor. Each phase of the full-bridge commutation control circuit also includes a capacitor C1, an inductor L1, a diode D1, and a diode DA. The current entry terminal of the diode DA is set at the IGBT chopper voltage regulator Q on the DC bus DC+. After the output terminal of component Q, one end of inductor L1 is connected to the current output terminal of diode DA, and the other end of inductor L1 is connected to the input terminal of the full-bridge control circuit; one end of capacitor C1 is connected to the input terminal of the full-bridge control circuit, and the other end of capacitor C1 is connected to the DC negative pole DC-; the current input terminal of diode D1 is connected to the DC negative pole DC-, and the current output terminal of diode D1 is connected to the current output terminal of diode DA. The IGBT chopper voltage regulator Q on the DC bus DC+, together with inductor L1, capacitor C1 and diode D1, form a single-phase Buck voltage regulator circuit for a full-magnetic DC motor.

[0030] The function of capacitor C1 is to absorb the high-voltage back EMF generated by the full-bridge control circuit when the current through the motor winding is commutated, protecting the four IGBT switching elements of the full-bridge control circuit - K1 / K2 / K3 / K4;

[0031] The function of capacitor C1 is also to absorb the back EMF generated by the change of magnetic flux in the motor winding during the operation of the motor;

[0032] The function of capacitor C1 is also to stabilize and filter the voltage of the Buck voltage regulator circuit composed of the IGBT chopper voltage regulator Q on the DC bus DC+, inductor L1, capacitor C1, and diode D1. The filtering effect of capacitor C1 prevents the high-frequency waveform during the voltage regulation process from entering the motor winding.

[0033] The function of capacitor C1 is to absorb the back electromotive force generated in the winding during the operation of the motor, thereby reducing the back electromotive force voltage at the front end of the full-bridge control circuit and enabling the diode DA to be turned on.

[0034] The IGBT chopper voltage regulator Q on the DC bus DC+ is controlled by a PWM duty cycle signal. In this example, 10 kHz is used and the duty cycle is set at 40%.

[0035] When the PWM duty cycle control signal of the IGBT chopper voltage regulator Q on the DC bus DC+ is high, the IGBT chopper voltage regulator Q is turned on. When the voltage at the output end of the diode DA is lower than the DC bus voltage, the diode DA is turned on, the inductor L1 is charged, and the current flowing through the inductor L1 increases linearly, providing energy to the load motor winding and charging the capacitor C1 at the same time.

[0036] When the PWM duty cycle control signal of the IGBT chopper voltage regulator element Q on the DC bus DC+ is at a low level, the IGBT chopper voltage regulator element Q is turned off, and the inductor L1 forms a discharge loop through the diode D1. At the same time, the capacitor C1 discharges the inductor L1 through the diode D1, so that the energy absorbed by the capacitor C1 is released into the motor winding to do work.

[0037] 3. Since the energy absorbed by capacitor C1 comes not only from the charging of the power supply but also includes the back EMF energy during the operation of the motor, its energy utilization rate is significantly better than that of the traditional BUCK circuit, which significantly improves the efficiency of the motor drive system and enables the output power of the motor to be greater than the input power.

[0038] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include," "comprise," or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations. The phrase "includes an element defined by..." does not exclude the presence of other identical elements in the process, method, article, or device that includes the element.

[0039] Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A high-efficiency all-magnetic DC motor control circuit, including a DC bus DC+, a DC negative pole DC-, an IGBT chopper voltage regulator Q on the DC bus DC+, a three-phase or multi-phase full-bridge control circuit, each phase of the full-bridge control circuit is composed of a full-bridge commutation control circuit composed of 4 IGBT switch elements -K1 / K2 / K3 / K4, controlling one phase winding of the motor, characterized in that: Each phase full-bridge commutation control circuit also includes a capacitor C1, an inductor L1, a diode D1, and a diode DA. The current entry end of the diode DA is arranged after the output end of the IGBT chopper voltage regulator element Q on the DC bus DC+. One end of the inductor L1 is connected to the current output end of the diode DA, and the other end of the inductor L1 is connected to the power input end of the full-bridge control circuit; one end of the capacitor C1 is connected to the power input end of the full-bridge control circuit, and the other end of the capacitor C1 is connected to the DC negative electrode DC-; the current entry end of the diode D1 is connected to the DC negative electrode DC-, and the current output end of the diode D1 is connected to the current output end of the diode DA. The IGBT chopper voltage regulator element Q on the DC bus DC+, the inductor L1, the capacitor C1, and the diode D1 form a single-phase Buck voltage regulator circuit for a full-magnetic DC motor; The function of the capacitor C1 is to absorb the high-voltage back electromotive force generated by the full-bridge control circuit when the current passing through the motor winding is commutated, thereby protecting the four IGBT switch elements - K1 / K2 / K3 / K4 of the full-bridge control circuit; The function of the capacitor C1 is also to absorb the back electromotive force generated by the change of magnetic flux in the motor winding during the operation of the motor; The function of the capacitor C1 is also to stabilize and filter the Buck voltage regulation circuit composed of the IGBT chopper voltage regulation element Q on the DC bus DC+, the inductor L1, the capacitor C1, and the diode D1; the function of the capacitor C1 is also to reduce the back-electromotive force voltage at the front end of the full-bridge control circuit by absorbing the back-electromotive force generated in the winding during the operation of the motor, so that the diode DA can be turned on; The IGBT chopper voltage regulator element Q on the DC bus DC+ is controlled by a PWM duty cycle signal; When the PWM duty cycle control signal of the IGBT chopper voltage regulator element Q on the DC bus DC+ is at a high level, the IGBT chopper voltage regulator element Q is turned on, and when the voltage at the output end of the diode DA is lower than the DC bus voltage, the diode DA is turned on, the inductor L1 is charged, and the current flowing through the inductor L1 increases linearly, providing energy to the load motor winding and charging the capacitor C1 at the same time; When the PWM duty cycle control signal of the IGBT chopper voltage regulator element Q on the DC bus DC+ is at a low level, the IGBT chopper voltage regulator element Q is turned off, the inductor L1 forms a discharge loop through the diode D1, and the capacitor C1 discharges the inductor L1 through the diode D1, so that the energy absorbed by the capacitor C1 is released into the motor winding to do work.

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