Magnetic control soft starter circuit of BUCK power supply

Abstract

The utility model provides a magnetic control soft starter circuit of a BUCK power supply. The magnetic control soft starter circuit comprises a starting circuit; the BUCK power supply circuit is connected with the starting circuit; wherein the starting circuit comprises a circuit breaker QF1, a bypass contactor KM1 and a saturable reactor T1; the BUCK power supply circuit comprises a power supply P1, a triode Q1, a diode D1 and a capacitor C1. The magnetic control soft starter circuit of the BUCK power supply has the characteristics of stable output, small ripple wave, high power factor and small harmonic wave.

Description

Technical Field

[0001] The utility model relates to the technical field of magnetically controlled soft starters, in particular to a magnetically controlled soft starter circuit of a BUCK power supply. Background Art

[0002] The magnetic control soft starter uses the adjustable reactance value of the AC winding of the saturable reactor to steplessly change the voltage at the motor winding terminal, thereby realizing the process of soft starting of the motor. The current limiting effect of the magnetic control soft starter is strong at the beginning of the start, and gradually weakens during the soft start process until the motor is started, and then the reactor is bypassed by the contactor to complete the entire start process. The saturable reactor is a nonlinear device with an iron core and has DC and AC windings. The power grid is connected to the input circuit breaker, and then connected to the motor winding circuit through the AC winding of the saturable reactor. By sending different DC currents into the DC winding of the saturable reactor, the inductive reactance of the AC winding of the saturable reactor can be changed, thereby changing the voltage at both ends of the AC winding of the saturable reactor, and finally realizing the regulation of the voltage at the motor winding terminal. The traditional magnetic control soft starter uses a thyristor rectifier voltage regulation circuit to control the current of the DC winding of the saturable reactor to change the reactance value of the AC winding, realize the regulation of the motor input voltage, and achieve the effect of soft starting.

[0003] The use of thyristor rectifier voltage regulation circuit to control the current of the DC winding of the saturable reactor has the disadvantages of large output ripple, low power factor, large harmonics, etc. The thyristor rectifier is naturally turned off by crossing the zero point, and it is not a device that can be fully controlled both on and off, which increases the risk of damaging other equipment and affects the stability of motor starting and the quality of the power grid. A technology is needed to improve the starting effect and the impact on the power grid. Utility Model Content

[0004] The utility model provides a magnetic control soft starter circuit of a BUCK power supply, which has the characteristics of stable output, small ripple, high power factor and small harmonic.

[0005] The embodiment of this specification discloses a magnetically controlled soft starter circuit of a BUCK power supply, including:

[0006] Start circuit;

[0007] BUCK power supply circuit, connected to the starting circuit;

[0008] The starting circuit includes a circuit breaker QF1, a bypass contactor KM1 and a saturable reactor T1; the BUCK power supply circuit includes a power supply P1, a transistor Q1, a diode D1 and a capacitor C1; the first end of the power supply P1 is connected to the collector of the transistor Q1, the second end of the power supply P1 is connected to the positive electrode of the diode D1, one end of the capacitor C1 and the pin 2 of the saturable reactor T1, the emitter of the transistor Q1 is connected to the negative electrode of the diode D1, the other end of the capacitor C1 and Pin 1 of the saturable inductor T1 is connected, the three pins of the output end of the circuit breaker QF1 are respectively connected with pin 3, pin 4 and pin 5 of the saturable inductor T1 in a one-to-one correspondence, pin 3, pin 4 and pin 5 of the saturable inductor T1 are respectively connected with pin 1, pin 2 and pin 3 of the bypass contactor KM1 in a one-to-one correspondence, and pin 4, pin 5 and pin 6 of the bypass contactor KM1 are respectively connected with pin 6, pin 7 and pin 8 of the saturable inductor T1 in a one-to-one correspondence.

[0009] In some embodiments of the present specification, the power supply P1 is an AC power supply, and the BUCK power supply circuit further includes a transformer T2, a thyristor V1, a thyristor V2, a thyristor V3, a thyristor V4, an output terminal U1 and an output terminal U2. The L terminal of the power supply P1 is connected to the pin 1 of the transformer T2, the N terminal of the power supply P1 is connected to the pin 2 of the transformer T2, the pin 3 of the transformer T2 is connected to the anode of the thyristor V1 and the cathode of the thyristor V3, the pin 4 of the transformer T2 is connected to the anode of the thyristor V2 and the cathode of the thyristor V4, the cathode of the thyristor V1 is connected to the cathode of the thyristor V2 and the output terminal U1, the output terminal U1 is connected to the collector of the triode Q1, the anode of the thyristor V3 is connected to the anode of the thyristor V4 and the output terminal U2, and the output terminal U2 is connected to the positive electrode of the diode D1, one end of the capacitor C1 and the pin 2 of the saturable reactor T1.

[0010] In some embodiments of the present specification, the power supply P1 is an AC power supply, and the BUCK power supply circuit further includes a transformer T3, a diode D4, a diode D5, a diode D6, a diode D7, an output terminal U3 and an output terminal U4. The L terminal of the power supply P1 is connected to pin 1 of the transformer T3, the N terminal of the power supply P1 is connected to pin 2 of the transformer T3, the pin 3 of the transformer T3 is connected to the positive electrode of the diode D4 and the negative electrode of the diode D5, the pin 4 of the transformer T3 is connected to the positive electrode of the diode D6 and the negative electrode of the diode D7, the negative electrode of the diode D4 is connected to the negative electrode of the diode D6 and the output terminal U3, the output terminal U3 is connected to the collector of the transistor Q1, the positive electrode of the diode D5 is connected to the positive electrode of the diode D7 and the output terminal U4, and the output terminal U4 is connected to the positive electrode of the diode D1, one end of the capacitor C1 and the pin 2 of the saturable reactor T1.

[0011] The embodiment of this specification also discloses a magnetically controlled soft starter circuit of a BUCK power supply, including:

[0012] Start circuit;

[0013] BUCK power supply circuit, connected to the starting circuit;

[0014] Wherein, the starting circuit includes a circuit breaker QF1, a bypass contactor KM1 and a saturable reactor T1; the BUCK power supply circuit includes a power supply P1, a MOS tube Q2, a MOS tube Q3, a diode D2, a diode D3, an inductor L1, a capacitor C2 and a capacitor C3; the first end of the power supply P1 is connected to one end of the capacitor C2, the drain of the MOS tube Q2 and the negative electrode of the diode D2, the second end of the power supply P1 is connected to the other end of the capacitor C2, the source of the MOS tube Q3, the positive electrode of the diode D3, one end of the capacitor C3 and the pin 2 of the saturable reactor T1, the positive electrode of the diode D2 is connected to the source of the MOS tube Q2, The drain of the MOS tube Q3, the negative electrode of the diode D3 and one end of the inductor L1 are connected, the other end of the inductor L1 is connected to the other end of the capacitor C3 and the pin 1 of the saturable reactor T1, the three pins of the output end of the circuit breaker QF1 are respectively connected to the pin 3, the pin 4 and the pin 5 of the saturable reactor T1 in a one-to-one correspondence, the pin 3, the pin 4 and the pin 5 of the saturable reactor T1 are respectively connected to the pin 1, the pin 2 and the pin 3 of the bypass contactor KM1 in a one-to-one correspondence, and the pin 4, the pin 5 and the pin 6 of the bypass contactor KM1 are respectively connected to the pin 6, the pin 7 and the pin 8 of the saturable reactor T1 in a one-to-one correspondence.

[0015] In some embodiments of the present specification, the power supply P1 is an AC power supply, and the BUCK power supply circuit further includes a transformer T2, a thyristor V1, a thyristor V2, a thyristor V3, a thyristor V4, an output terminal U1 and an output terminal U2, the L terminal of the power supply P1 is connected to the pin 1 of the transformer T2, the N terminal of the power supply P1 is connected to the pin 2 of the transformer T2, the pin 3 of the transformer T2 is connected to the anode of the thyristor V1 and the cathode of the thyristor V3, and the pin 4 of the transformer T2 is connected to the thyristor V1. The anode of the thyristor V2 is connected to the cathode of the thyristor V4, the cathode of the thyristor V1 is connected to the cathode of the thyristor V2 and the output end U1, the output end U1 is connected to one end of the capacitor C2, the drain of the MOS tube Q2 and the negative electrode of the diode D2, the anode of the thyristor V3 is connected to the anode of the thyristor V4 and the output end U2, and the output end U2 is connected to the other end of the capacitor C2, the source of the MOS tube Q3, the positive electrode of the diode D3, one end of the capacitor C3 and the pin 2 of the saturable reactor T1.

[0016] In some embodiments of the present specification, the power supply P1 is an AC power supply, and the BUCK power supply circuit further includes a transformer T3, a diode D4, a diode D5, a diode D6, a diode D7, an output terminal U3 and an output terminal U4, the L terminal of the power supply P1 is connected to the pin 1 of the transformer T3, the N terminal of the power supply P1 is connected to the pin 2 of the transformer T3, the pin 3 of the transformer T3 is connected to the positive electrode of the diode D4 and the negative electrode of the diode D5, and the pin 4 of the transformer T3 is connected to the diode The anode of the transistor D6 is connected to the cathode of the diode D7, the cathode of the diode D4 is connected to the cathode of the diode D6 and the output terminal U3, the output terminal U3 is connected to one end of the capacitor C2, the drain of the MOS transistor Q2 and the cathode of the diode D2, the anode of the diode D5 is connected to the anode of the diode D7 and the output terminal U4, and the output terminal U4 is connected to the other end of the capacitor C2, the source of the MOS transistor Q3, the anode of the diode D3, one end of the capacitor C3 and the pin 2 of the saturable reactor T1.

[0017] The embodiment of this specification also discloses a magnetically controlled soft starter circuit of a BUCK power supply, including:

[0018] Start circuit;

[0019] BUCK power supply circuit, connected to the starting circuit;

[0020] Wherein, the starting circuit includes a circuit breaker QF1, a bypass contactor KM1 and a saturable reactor T1; the BUCK power supply circuit includes a power supply UIN, a power tube VT1, a power tube VT2, a power tube VT3, a power tube VT4, a diode VD1, a diode VD2, a diode VD3, a diode VD4, a diode VDa1, a diode VDa2, a diode VDR1, a diode VDR2, a capacitor C4, a capacitor C5, a capacitor C6, a capacitor C7, a capacitor Ca1, a capacitor Ca2, a capacitor Cof, an inductor La, an inductor Lr, an inductor Lof and a transformer TR;

[0021] One end of the power supply UIN is grounded, and the other end of the power supply UIN is connected to the collector of the power tube VT1, the cathode of the diode VD1, one end of the capacitor C7, the collector of the power tube VT2, the cathode of the diode VD2, one end of the capacitor C5, one end of the capacitor Ca1 and the cathode of the diode VDa1. The emitter of the power tube VT1 is connected to the collector of the power tube VT3, the anode of the diode VD1, the cathode of the diode VD3, the other end of the capacitor C7, one end of the capacitor C4 and one end of the primary side of the transformer TR. The emitter of the power tube VT3 is connected to the anode of the diode VD3 and the other end of the capacitor C4 and then grounded. The other end of the primary side of the transformer TR is connected to one end of the inductor Lr, the other end of the inductor Lr is connected to the emitter of the power tube VT2, the positive electrode of the diode VD2, the other end of the capacitor C5, one end of the inductor La, the collector of the power tube VT4, the negative electrode of the diode VD4 and one end of the capacitor C6, the other end of the inductor La is connected to the other end of the capacitor Ca1, the positive electrode of the diode VDa1, one end of the capacitor Ca2 and the negative electrode of the diode VDa2, the emitter of the power tube VT4 is connected to the positive electrode of the diode VD4, the other end of the capacitor C6, the other end of the capacitor Ca2 and the positive electrode of the diode VDa2 and then grounded;

[0022] One end of the secondary side of the transformer TR is connected to the positive electrode of the diode VDR1, the other end of the secondary side of the transformer TR is connected to the positive electrode of the diode VDR2, the negative electrode of the diode VDR1 is connected to one end of the inductor Lof, the other end of the inductor Lof is connected to one end of the capacitor Cof and pin 1 of the saturable reactor T1, the midpoint of the secondary side of the transformer TR is connected to the other end of the capacitor Cof and pin 2 of the saturable reactor T1, the three pins of the output end of the circuit breaker QF1 are respectively connected to pin 3, pin 4 and pin 5 of the saturable reactor T1 in one-to-one correspondence, pin 3, pin 4 and pin 5 of the saturable reactor T1 are respectively connected to pin 1, pin 2 and pin 3 of the bypass contactor KM1 in one-to-one correspondence, and pin 4, pin 5 and pin 6 of the bypass contactor KM1 are respectively connected to pin 6, pin 7 and pin 8 of the saturable reactor T1 in one-to-one correspondence.

[0023] The embodiments of this specification can at least achieve the following beneficial effects:

[0024] The BUCK power supply circuit is used to control the current of the DC winding of the saturable inductor, which has the characteristics of high switching control frequency and complete shutdown, stable output, small ripple, high power factor and small harmonics. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 It is a schematic diagram of a magnetically controlled soft starter circuit of a BUCK power supply involved in some embodiments of the present utility model.

[0027] Figure 2 Schematic diagram of a BUCK power supply circuit involved in some embodiments of the present invention.

[0028] Figure 3 Schematic diagram of a BUCK power supply circuit involved in other embodiments of the present invention.

[0029] Figure 4 It is a structural schematic diagram of a magnetically controlled soft starter circuit of a BUCK power supply involved in other embodiments of the utility model.

[0030] Figure 5 The following are schematic diagrams of BUCK power supply circuits involved in some other embodiments of the present invention. DETAILED DESCRIPTION

[0031] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the embodiments of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0032] In the description of the embodiments of the present invention, it should be understood that the terms "length", "vertical", "horizontal", "top", "bottom", etc. indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present invention.

[0033] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present utility model, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0034] In the embodiments of the present utility model, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present utility model can be understood according to specific circumstances.

[0035] In the embodiments of the present utility model, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or may include the first and second features not being in direct contact but being in contact through another feature between them. Moreover, the first feature being "above", "above" and "above" the second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature includes the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0036] The disclosure below provides many different embodiments or examples for realizing different structures of the embodiments of the present utility model. In order to simplify the disclosure of the embodiments of the present utility model, the components and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the embodiments of the present utility model. In addition, the embodiments of the present utility model can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed.

[0037] The embodiments of the present utility model are described in detail below with reference to the accompanying drawings.

[0038] like Figure 1 As shown, the embodiment of this specification discloses a magnetically controlled soft starter circuit of a BUCK power supply, including:

[0039] Start circuit;

[0040] BUCK power supply circuit, connected to the starting circuit;

[0041] The starting circuit includes a circuit breaker QF1, a bypass contactor KM1 and a saturable reactor T1; the BUCK power supply circuit includes a power supply P1, a transistor Q1, a diode D1 and a capacitor C1; the first end of the power supply P1 is connected to the collector of the transistor Q1, the second end of the power supply P1 is connected to the positive electrode of the diode D1, one end of the capacitor C1 and the pin 2 of the saturable reactor T1, the emitter of the transistor Q1 is connected to the negative electrode of the diode D1, the other end of the capacitor C1 and Pin 1 of the saturable inductor T1 is connected, the three pins of the output end of the circuit breaker QF1 are respectively connected with pin 3, pin 4 and pin 5 of the saturable inductor T1 in a one-to-one correspondence, pin 3, pin 4 and pin 5 of the saturable inductor T1 are respectively connected with pin 1, pin 2 and pin 3 of the bypass contactor KM1 in a one-to-one correspondence, and pin 4, pin 5 and pin 6 of the bypass contactor KM1 are respectively connected with pin 6, pin 7 and pin 8 of the saturable inductor T1 in a one-to-one correspondence.

[0042] In this embodiment, the processor controls the coil of the bypass contactor KM1 to gain or lose power, thereby controlling the corresponding contacts to be closed or opened, thereby achieving the purpose of whether to use the saturable inductor T1; the processor can control whether the transistor Q1 is turned on or not. When it is turned on, the current of the DC winding of the saturable inductor T1 can be controlled through the transistor Q1, the diode D1 and the capacitor C1.

[0043] In some embodiments, the power source P1 is an AC power source, such as Figure 2As shown, the BUCK power supply circuit also includes a transformer T2, a thyristor V1, a thyristor V2, a thyristor V3, a thyristor V4, an output terminal U1 and an output terminal U2, the L terminal of the power supply P1 is connected to the pin 1 of the transformer T2, the N terminal of the power supply P1 is connected to the pin 2 of the transformer T2, the pin 3 of the transformer T2 is connected to the anode of the thyristor V1 and the cathode of the thyristor V3, the pin 4 of the transformer T2 is connected to the anode of the thyristor V2 and the cathode of the thyristor V4, the cathode of the thyristor V1 is connected to the cathode of the thyristor V2 and the output terminal U1, the output terminal U1 is connected to the collector of the triode Q1, the anode of the thyristor V3 is connected to the anode of the thyristor V4 and the output terminal U2, and the output terminal U2 is connected to the positive electrode of the diode D1, one end of the capacitor C1 and the pin 2 of the saturable reactor T1.

[0044] In this embodiment, a transformer T2, a thyristor V1, a thyristor V2, a thyristor V3 and a thyristor V4 are used for rectification.

[0045] In some embodiments, the power source P1 is an AC power source, such as Figure 3 As shown, the BUCK power supply circuit also includes a transformer T3, a diode D4, a diode D5, a diode D6, a diode D7, an output terminal U3 and an output terminal U4, the L terminal of the power supply P1 is connected to the pin 1 of the transformer T3, the N terminal of the power supply P1 is connected to the pin 2 of the transformer T3, the pin 3 of the transformer T3 is connected to the positive electrode of the diode D4 and the negative electrode of the diode D5, the pin 4 of the transformer T3 is connected to the positive electrode of the diode D6 and the negative electrode of the diode D7, the negative electrode of the diode D4 is connected to the negative electrode of the diode D6 and the output terminal U3, the output terminal U3 is connected to the collector of the transistor Q1, the positive electrode of the diode D5 is connected to the positive electrode of the diode D7 and the output terminal U4, and the output terminal U4 is connected to the positive electrode of the diode D1, one end of the capacitor C1 and the pin 2 of the saturable reactor T1.

[0046] In this embodiment, a transformer T3, a diode D4, a diode D5, a diode D6 and a diode D7 are used for rectification.

[0047] like Figure 4 As shown, the embodiment of this specification also discloses a magnetically controlled soft starter circuit of a BUCK power supply, including:

[0048] Start circuit;

[0049] BUCK power supply circuit, connected to the starting circuit;

[0050] Wherein, the starting circuit includes a circuit breaker QF1, a bypass contactor KM1 and a saturable reactor T1; the BUCK power supply circuit includes a power supply P1, a MOS tube Q2 (or a similar power electronic switching device such as IGBT), a MOS tube Q3 (or a similar power electronic switching device such as IGBT), a diode D2, a diode D3, an inductor L1, a capacitor C2 and a capacitor C3; the first end of the power supply P1 (the positive electrode in the case of a DC power supply) is connected to one end of the capacitor C2, the drain of the MOS tube Q2 and the negative electrode of the diode D2, and the second end of the power supply P1 (the negative electrode in the case of a DC power supply) is connected to the other end of the capacitor C2, the source of the MOS tube Q3, the positive electrode of the diode D3, one end of the capacitor C3 and the gate of the saturable reactor T1. The anode of the diode D2 is connected to the source of the MOS tube Q2, the drain of the MOS tube Q3, the cathode of the diode D3 and one end of the inductor L1, the other end of the inductor L1 is connected to the other end of the capacitor C3 and the pin 1 of the saturable reactor T1, the three pins of the output end of the circuit breaker QF1 are respectively connected with the pin 3, the pin 4 and the pin 5 of the saturable reactor T1 in a one-to-one correspondence, the pin 3, the pin 4 and the pin 5 of the saturable reactor T1 are respectively connected with the pin 1, the pin 2 and the pin 3 of the bypass contactor KM1 in a one-to-one correspondence, and the pin 4, the pin 5 and the pin 6 of the bypass contactor KM1 are respectively connected with the pin 6, the pin 7 and the pin 8 of the saturable reactor T1 in a one-to-one correspondence.

[0051] In this embodiment, the processor controls the coil of the bypass contactor KM1 to gain or lose power, thereby controlling the corresponding contacts to be closed or opened, thereby achieving the purpose of whether to use the saturable reactor T1; the processor can control whether the MOS tube Q2 and the MOS tube Q3 are turned on, that is, the current of the DC winding of the saturable reactor T1 can be controlled by the MOS tube Q2, the MOS tube Q3, the diode D2, the diode D3, the inductor L1, the capacitor C2 and the capacitor C3.

[0052] In some embodiments, the power source P1 is an AC power source, such as Figure 2As shown, the BUCK power supply circuit also includes a transformer T2, a thyristor V1, a thyristor V2, a thyristor V3, a thyristor V4, an output terminal U1 and an output terminal U2, the L terminal of the power supply P1 is connected to the pin 1 of the transformer T2, the N terminal of the power supply P1 is connected to the pin 2 of the transformer T2, the pin 3 of the transformer T2 is connected to the anode of the thyristor V1 and the cathode of the thyristor V3, the pin 4 of the transformer T2 is connected to the anode of the thyristor V2 and the cathode of the thyristor V The cathode of the thyristor V1 is connected to the cathode of the thyristor V2 and the output terminal U1, the output terminal U1 is connected to one end of the capacitor C2, the drain of the MOS tube Q2 and the negative electrode of the diode D2, the anode of the thyristor V3 is connected to the anode of the thyristor V4 and the output terminal U2, and the output terminal U2 is connected to the other end of the capacitor C2, the source of the MOS tube Q3, the positive electrode of the diode D3, one end of the capacitor C3 and the pin 2 of the saturable reactor T1.

[0053] In some embodiments, the power source P1 is an AC power source, such as Figure 3 As shown, the BUCK power supply circuit also includes a transformer T3, a diode D4, a diode D5, a diode D6, a diode D7, an output terminal U3 and an output terminal U4, the L terminal of the power supply P1 is connected to the pin 1 of the transformer T3, the N terminal of the power supply P1 is connected to the pin 2 of the transformer T3, the pin 3 of the transformer T3 is connected to the positive electrode of the diode D4 and the negative electrode of the diode D5, the pin 4 of the transformer T3 is connected to the positive electrode of the diode D6 and the negative electrode of the diode D7, the negative electrode of the diode D4 is connected to the negative electrode of the diode D6 and the output terminal U3, the output terminal U3 is connected to one end of the capacitor C2, the drain of the MOS tube Q2 and the negative electrode of the diode D2, the positive electrode of the diode D5 is connected to the positive electrode of the diode D7 and the output terminal U4, and the output terminal U4 is connected to the other end of the capacitor C2, the source of the MOS tube Q3, the positive electrode of the diode D3, one end of the capacitor C3 and the pin 2 of the saturable reactor T1.

[0054] like Figure 5 As shown, the embodiment of this specification also discloses a magnetically controlled soft starter circuit of a BUCK power supply, including:

[0055] Start circuit;

[0056] BUCK power supply circuit, connected to the starting circuit;

[0057] Wherein, the starting circuit includes a circuit breaker QF1, a bypass contactor KM1 and a saturable reactor T1; the BUCK power supply circuit includes a power supply UIN, a power tube VT1, a power tube VT2, a power tube VT3, a power tube VT4, a diode VD1, a diode VD2, a diode VD3, a diode VD4, a diode VDa1, a diode VDa2, a diode VDR1, a diode VDR2, a capacitor C4, a capacitor C5, a capacitor C6, a capacitor C7, a capacitor Ca1, a capacitor Ca2, a capacitor Cof, an inductor La, an inductor Lr, an inductor Lof and a transformer TR;

[0058] One end of the power supply UIN is grounded, and the other end of the power supply UIN is connected to the collector of the power tube VT1, the cathode of the diode VD1, one end of the capacitor C7, the collector of the power tube VT2, the cathode of the diode VD2, one end of the capacitor C5, one end of the capacitor Ca1 and the cathode of the diode VDa1. The emitter of the power tube VT1 is connected to the collector of the power tube VT3, the anode of the diode VD1, the cathode of the diode VD3, the other end of the capacitor C7, one end of the capacitor C4 and one end of the primary side of the transformer TR. The emitter of the power tube VT3 is connected to the anode of the diode VD3 and the other end of the capacitor C4 and then grounded. The other end of the primary side of the transformer TR is connected to one end of the inductor Lr, the other end of the inductor Lr is connected to the emitter of the power tube VT2, the positive electrode of the diode VD2, the other end of the capacitor C5, one end of the inductor La, the collector of the power tube VT4, the negative electrode of the diode VD4 and one end of the capacitor C6, the other end of the inductor La is connected to the other end of the capacitor Ca1, the positive electrode of the diode VDa1, one end of the capacitor Ca2 and the negative electrode of the diode VDa2, the emitter of the power tube VT4 is connected to the positive electrode of the diode VD4, the other end of the capacitor C6, the other end of the capacitor Ca2 and the positive electrode of the diode VDa2 and then grounded;

[0059] One end of the secondary side of the transformer TR is connected to the positive electrode of the diode VDR1, the other end of the secondary side of the transformer TR is connected to the positive electrode of the diode VDR2, the negative electrode of the diode VDR1 is connected to one end of the inductor Lof, the other end of the inductor Lof is connected to one end of the capacitor Cof and pin 1 of the saturable reactor T1, the midpoint of the secondary side of the transformer TR is connected to the other end of the capacitor Cof and pin 2 of the saturable reactor T1, the three pins of the output end of the circuit breaker QF1 are respectively connected to pin 3, pin 4 and pin 5 of the saturable reactor T1 in one-to-one correspondence, pin 3, pin 4 and pin 5 of the saturable reactor T1 are respectively connected to pin 1, pin 2 and pin 3 of the bypass contactor KM1 in one-to-one correspondence, and pin 4, pin 5 and pin 6 of the bypass contactor KM1 are respectively connected to pin 6, pin 7 and pin 8 of the saturable reactor T1 in one-to-one correspondence.

[0060] In this embodiment, the leakage inductance of the transformer and the parasitic capacitance of the power tube are used to achieve zero voltage switching. At the same time, the current of the DC winding of the saturable inductor T1 is controlled by the power tube VT1, the power tube VT2, the power tube VT3, the power tube VT4, the diode VD1, the diode VD2, the diode VD3, the diode VD4, the diode VDa1, the diode VDa2, the diode VDR1, the diode VDR2, the capacitor C4, the capacitor C5, the capacitor C6, the capacitor C7, the capacitor Ca1, the capacitor Ca2, the capacitor Cof, the inductor La, the inductor Lr, the inductor Lof and the transformer TR.

[0061] In summary, the use of different BUCK power supply circuits in the above embodiments has a higher power factor and less harmonics than thyristor chopper rectification; the DC chopping frequency of IGBT-type controllable devices is dozens of times that of thyristor rectification chopping frequency. With the same filtering parameters, the ripple is smaller, and the control response is fast, which can control the output current faster and more accurately, making the start-stop effect of the magnetic control soft starter better and more stable. In addition, the opening and closing of IGBT-type controllable devices are fully controllable, further improving the reliability of the product.

[0062] It should be understood that the input end of the circuit breaker QF1 is connected to the corresponding power supply according to the actual situation, the magnetic control soft starter requires a corresponding processor for control, and the pins 6, 7 and 8 of the saturable inductor T1 are connected to the motor M. These power supplies, processors and motors M do not belong to the part of the magnetic control soft starter, and will not be described here. Just refer to the prior art; for example, the processor can be a MUC, DSP, PLC, ASIC or FPGA chip; for example, by controlling the power gain or loss of the coil corresponding to the bypass contactor KM1 through the processor, the closing or opening of the bypass contactor KM1 can be controlled; for example, the above-mentioned transistors, MOS tubes, thyristors and power tubes can all be controlled by the processor, that is, the base of the transistor, the gate of the MOS tube, the control electrode of the thyristor and the gate of the power tube are respectively connected to the processor.

[0063] The above embodiments describe multiple specific implementations of the present invention, but those skilled in the art should understand that various changes or modifications can be made to these implementations without departing from the principles and essence of the present invention, but these changes and modifications are all within the scope of protection of the present invention.

Claims

1. A magnetically controlled soft starter circuit for a BUCK power supply, characterized in that: include: Start circuit; BUCK power supply circuit, connected to the starting circuit; The starting circuit includes a circuit breaker QF1, a bypass contactor KM1 and a saturable reactor T1; the BUCK power supply circuit includes a power supply P1, a transistor Q1, a diode D1 and a capacitor C1; the first end of the power supply P1 is connected to the collector of the transistor Q1, the second end of the power supply P1 is connected to the positive electrode of the diode D1, one end of the capacitor C1 and the pin 2 of the saturable reactor T1, the emitter of the transistor Q1 is connected to the negative electrode of the diode D1, the other end of the capacitor C1 and Pin 1 of the saturable inductor T1 is connected, the three pins of the output end of the circuit breaker QF1 are respectively connected with pin 3, pin 4 and pin 5 of the saturable inductor T1 in a one-to-one correspondence, pin 3, pin 4 and pin 5 of the saturable inductor T1 are respectively connected with pin 1, pin 2 and pin 3 of the bypass contactor KM1 in a one-to-one correspondence, and pin 4, pin 5 and pin 6 of the bypass contactor KM1 are respectively connected with pin 6, pin 7 and pin 8 of the saturable inductor T1 in a one-to-one correspondence.

2. The magnetically controlled soft starter circuit of the BUCK power supply according to claim 1, characterized in that: The power supply P1 is an AC power supply, and the BUCK power supply circuit further includes a transformer T2, a thyristor V1, a thyristor V2, a thyristor V3, a thyristor V4, an output terminal U1 and an output terminal U2. The L terminal of the power supply P1 is connected to the pin 1 of the transformer T2, the N terminal of the power supply P1 is connected to the pin 2 of the transformer T2, the pin 3 of the transformer T2 is connected to the anode of the thyristor V1 and the cathode of the thyristor V3, the pin 4 of the transformer T2 is connected to the anode of the thyristor V2 and the cathode of the thyristor V4, the cathode of the thyristor V1 is connected to the cathode of the thyristor V2 and the output terminal U1, the output terminal U1 is connected to the collector of the triode Q1, the anode of the thyristor V3 is connected to the anode of the thyristor V4 and the output terminal U2, and the output terminal U2 is connected to the positive electrode of the diode D1, one end of the capacitor C1 and the pin 2 of the saturable reactor T1.

3. The magnetically controlled soft starter circuit of the BUCK power supply according to claim 1, characterized in that: The power supply P1 is an AC power supply, and the BUCK power supply circuit further includes a transformer T3, a diode D4, a diode D5, a diode D6, a diode D7, an output terminal U3 and an output terminal U4. The L terminal of the power supply P1 is connected to the pin 1 of the transformer T3, the N terminal of the power supply P1 is connected to the pin 2 of the transformer T3, the pin 3 of the transformer T3 is connected to the positive electrode of the diode D4 and the negative electrode of the diode D5, the pin 4 of the transformer T3 is connected to the positive electrode of the diode D6 and the negative electrode of the diode D7, the negative electrode of the diode D4 is connected to the negative electrode of the diode D6 and the output terminal U3, the output terminal U3 is connected to the collector of the transistor Q1, the positive electrode of the diode D5 is connected to the positive electrode of the diode D7 and the output terminal U4, and the output terminal U4 is connected to the positive electrode of the diode D1, one end of the capacitor C1 and the pin 2 of the saturable reactor T1.

4. A magnetically controlled soft starter circuit for a BUCK power supply, characterized in that: include: Start circuit; BUCK power supply circuit, connected to the starting circuit; Wherein, the starting circuit includes a circuit breaker QF1, a bypass contactor KM1 and a saturable reactor T1; the BUCK power supply circuit includes a power supply P1, a MOS tube Q2, a MOS tube Q3, a diode D2, a diode D3, an inductor L1, a capacitor C2 and a capacitor C3; the first end of the power supply P1 is connected to one end of the capacitor C2, the drain of the MOS tube Q2 and the negative electrode of the diode D2, the second end of the power supply P1 is connected to the other end of the capacitor C2, the source of the MOS tube Q3, the positive electrode of the diode D3, one end of the capacitor C3 and the pin 2 of the saturable reactor T1, the positive electrode of the diode D2 is connected to the source of the MOS tube Q2, The drain of the MOS tube Q3, the negative electrode of the diode D3 and one end of the inductor L1 are connected, the other end of the inductor L1 is connected to the other end of the capacitor C3 and the pin 1 of the saturable reactor T1, the three pins of the output end of the circuit breaker QF1 are respectively connected to the pin 3, the pin 4 and the pin 5 of the saturable reactor T1 in a one-to-one correspondence, the pin 3, the pin 4 and the pin 5 of the saturable reactor T1 are respectively connected to the pin 1, the pin 2 and the pin 3 of the bypass contactor KM1 in a one-to-one correspondence, and the pin 4, the pin 5 and the pin 6 of the bypass contactor KM1 are respectively connected to the pin 6, the pin 7 and the pin 8 of the saturable reactor T1 in a one-to-one correspondence.

5. The magnetically controlled soft starter circuit of the BUCK power supply according to claim 4, characterized in that: The power supply P1 is an AC power supply, and the BUCK power supply circuit also includes a transformer T2, a thyristor V1, a thyristor V2, a thyristor V3, a thyristor V4, an output terminal U1 and an output terminal U2. The L terminal of the power supply P1 is connected to the pin 1 of the transformer T2, the N terminal of the power supply P1 is connected to the pin 2 of the transformer T2, the pin 3 of the transformer T2 is connected to the anode of the thyristor V1 and the cathode of the thyristor V3, the pin 4 of the transformer T2 is connected to the anode of the thyristor V2, and the pin 5 of the transformer T2 is connected to the cathode of the thyristor V3. The cathode of the thyristor V1 is connected to the cathode of the thyristor V2 and the output terminal U1, the output terminal U1 is connected to one end of the capacitor C2, the drain of the MOS tube Q2 and the negative electrode of the diode D2, the anode of the thyristor V3 is connected to the anode of the thyristor V4 and the output terminal U2, and the output terminal U2 is connected to the other end of the capacitor C2, the source of the MOS tube Q3, the positive electrode of the diode D3, one end of the capacitor C3 and the pin 2 of the saturable reactor T1.

6. The magnetically controlled soft starter circuit of the BUCK power supply according to claim 4, characterized in that: The power supply P1 is an AC power supply, and the BUCK power supply circuit further includes a transformer T3, a diode D4, a diode D5, a diode D6, a diode D7, an output terminal U3 and an output terminal U4. The L terminal of the power supply P1 is connected to the pin 1 of the transformer T3, the N terminal of the power supply P1 is connected to the pin 2 of the transformer T3, the pin 3 of the transformer T3 is connected to the positive electrode of the diode D4 and the negative electrode of the diode D5, the pin 4 of the transformer T3 is connected to the positive electrode of the diode D6 and the negative electrode of the diode D7, the negative electrode of the diode D4 is connected to the negative electrode of the diode D6 and the output terminal U3, the output terminal U3 is connected to one end of the capacitor C2, the drain of the MOS tube Q2 and the negative electrode of the diode D2, the positive electrode of the diode D5 is connected to the positive electrode of the diode D7 and the output terminal U4, and the output terminal U4 is connected to the other end of the capacitor C2, the source of the MOS tube Q3, the positive electrode of the diode D3, one end of the capacitor C3 and the pin 2 of the saturable reactor T1.

7. A magnetically controlled soft starter circuit for a BUCK power supply, characterized in that: include: Start circuit; BUCK power supply circuit, connected to the starting circuit; Wherein, the starting circuit includes a circuit breaker QF1, a bypass contactor KM1 and a saturable reactor T1; the BUCK power supply circuit includes a power supply UIN, a power tube VT1, a power tube VT2, a power tube VT3, a power tube VT4, a diode VD1, a diode VD2, a diode VD3, a diode VD4, a diode VDa1, a diode VDa2, a diode VDR1, a diode VDR2, a capacitor C4, a capacitor C5, a capacitor C6, a capacitor C7, a capacitor Ca1, a capacitor Ca2, a capacitor Cof, an inductor La, an inductor Lr, an inductor Lof and a transformer TR; One end of the power supply UIN is grounded, and the other end of the power supply UIN is connected to the collector of the power tube VT1, the cathode of the diode VD1, one end of the capacitor C7, the collector of the power tube VT2, the cathode of the diode VD2, one end of the capacitor C5, one end of the capacitor Ca1 and the cathode of the diode VDa1. The emitter of the power tube VT1 is connected to the collector of the power tube VT3, the anode of the diode VD1, the cathode of the diode VD3, the other end of the capacitor C7, one end of the capacitor C4 and one end of the primary side of the transformer TR. The emitter of the power tube VT3 is connected to the anode of the diode VD3 and the other end of the capacitor C4 and then grounded. The other end of the primary side of the transformer TR is connected to one end of the inductor Lr, the other end of the inductor Lr is connected to the emitter of the power tube VT2, the positive electrode of the diode VD2, the other end of the capacitor C5, one end of the inductor La, the collector of the power tube VT4, the negative electrode of the diode VD4 and one end of the capacitor C6, the other end of the inductor La is connected to the other end of the capacitor Ca1, the positive electrode of the diode VDa1, one end of the capacitor Ca2 and the negative electrode of the diode VDa2, the emitter of the power tube VT4 is connected to the positive electrode of the diode VD4, the other end of the capacitor C6, the other end of the capacitor Ca2 and the positive electrode of the diode VDa2 and then grounded; One end of the secondary side of the transformer TR is connected to the positive electrode of the diode VDR1, the other end of the secondary side of the transformer TR is connected to the positive electrode of the diode VDR2, the negative electrode of the diode VDR1 is connected to one end of the inductor Lof, the other end of the inductor Lof is connected to one end of the capacitor Cof and pin 1 of the saturable reactor T1, the midpoint of the secondary side of the transformer TR is connected to the other end of the capacitor Cof and pin 2 of the saturable reactor T1, the three pins of the output end of the circuit breaker QF1 are respectively connected to pin 3, pin 4 and pin 5 of the saturable reactor T1 in one-to-one correspondence, pin 3, pin 4 and pin 5 of the saturable reactor T1 are respectively connected to pin 1, pin 2 and pin 3 of the bypass contactor KM1 in one-to-one correspondence, and pin 4, pin 5 and pin 6 of the bypass contactor KM1 are respectively connected to pin 6, pin 7 and pin 8 of the saturable reactor T1 in one-to-one correspondence.

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