An AC electronic switching device

Abstract

This invention discloses an AC electronic switching device, comprising a switching module (1), an absorption circuit (2), a discharge circuit (3), and a controller (15). The switching module (1) is used for rapid switching of AC current, while the absorption circuit (2) and discharge circuit (3) absorb the energy when the switching module (1) is turned off, and protect the normal operation of the switching module (1). The controller (15) communicates with a host computer to control the normal operation of the above-mentioned functions. The power electronic switching device of this invention has a simple structure, low cost, low loss, high reliability, and fast switching speed.

Description

Technical Field

[0001] This invention belongs to the field of electrical engineering technology, and in particular relates to an AC electronic switch device that can be quickly turned on and off. Background Technology

[0002] AC electronic switches, also known as solid-state electronic switches, can control the switching on and off of alternating current. They are often implemented using thyristors connected in parallel, such as... Figure 1 As shown. AC electronic switches can be easily controlled by low-voltage signals, such as using an MCU, making them very convenient for various applications and showing great promise.

[0003] Solid-state switches constructed using anti-parallel thyristors have the advantages of high voltage and high current, but they cannot be turned off by weak electrical signals. Therefore, their use is greatly limited in applications requiring rapid turn-off.

[0004] Patent 201310260839.4 discloses an IGBT-based electronic switch, such as... Figure 2 The invention demonstrates that it can quickly achieve bidirectional current cut-off and conduction, but each set of switches requires two capacitors and two discharge resistors. If it is used to form a multi-way switch (such as a commonly used three-phase switch), it requires twice the number of capacitors and resistors as the switches. Therefore, the number of components is large, the cost is high, and it is necessary to bring out the switch midpoint, which makes the circuit complex and affects the reliability of the device. In addition, the capacitor voltage is uncontrollable. When the switch is in the conducting state, the capacitor gradually discharges to zero voltage. When the switch is turned off again, the main circuit current will continue to flow through the capacitor, charging the capacitor from zero voltage. Therefore, the turn-off time of this invention is relatively long and cannot achieve rapid turn-off.

[0005] like Figure 3 The existing technology shown has a simple circuit, but when an overcurrent or short circuit occurs and the switch needs to be turned off, the RC absorption circuit cannot completely absorb the induced voltage. Therefore, MOV devices, such as varistors, are added. However, such surge protection devices have low reliability and will fail under large impact energy or multiple impacts, resulting in a decrease in the life and reliability of the device.

[0006] Therefore, it is evident that existing solid-state electronic switch circuit structures suffer from drawbacks such as complex structure, high cost, low reliability, and slow speed. Given these shortcomings, improvements to existing solid-state electronic switches are necessary. Summary of the Invention

[0007] The present invention aims to design a power electronic switching device that is simple in structure, low in cost, low in loss, highly reliable, and fast in switching speed.

[0008] An AC electronic switch device of the present invention includes a switch module (1), the switch module (1) includes a power input port A, an output port B and a midpoint port (Z), the switch module is used to open or close the AC current path between the input port A and the output port B;

[0009] It also includes an absorption circuit (2), which is connected to the input port A, output port B, midpoint port (Z) and power supply N line of the switch module (1). The absorption circuit (2) contains a capacitor that can store electrical energy, which is used to absorb the electrical energy in the loop inductance during the switching module (1) turn-off process.

[0010] It also includes a discharge circuit (3), which is connected to the positive (+) and negative (-) terminals of the absorption circuit (2) to protect the absorption circuit (2) and the switching module (1) from damage due to excessive voltage;

[0011] It also includes a controller (15), which is connected to the switch module (1), the absorption circuit (2), and the discharge circuit (3) by signal connection; the controller (15) performs on / off operation on the switch module (1) according to the received external switch operation signal. At the same time, the controller (15) detects the positive (+) and negative (-) terminal voltage of the absorption circuit (2). When the voltage exceeds a set value, it issues a discharge command to the discharge circuit (3) until the positive (+) and negative (-) terminal voltage of the absorption circuit (2) does not exceed the set value.

[0012] An AC electronic switching device of the present invention includes a switching module (1) comprising a semiconductor switching device (4) connected in series with a reverse common source, the two ends of which are connected to an input port A and an output port B respectively, the midpoint of which is connected to the midpoint port (Z) and to the absorption circuit (2); the semiconductor switching device (4) connected in series with the reverse common source is used to cut off or connect the bidirectional current flowing between the input port A and the output port B, and the semiconductor switching device (4) may be one of a reverse-conducting power semiconductor device IGBT, MOSFET or IGCT.

[0013] An AC electronic switching device of the present invention, wherein the switching module (1) may also include a semiconductor switching device (5) connected in parallel with a common drain in reverse, wherein its two ends are respectively connected to the input port A and the output port B, the midpoint is connected to the midpoint port (Z) and connected to the absorption circuit (2); the semiconductor switching device (5) connected in reverse parallel is used to cut off or connect the bidirectional current flowing between the input port A and the output port B, and the semiconductor switching device (5) may be one of the reverse-conducting power semiconductor devices IGBT, MOSFET or IGCT.

[0014] An AC electronic switch device of the present invention includes an absorption circuit (2) comprising three diodes (D) with one end connected to an input port A, an output port B and a power supply N line respectively, and the other end of the three diodes (D) connected to a capacitor (C), the other end of the capacitor (C) connected to the midpoint port (Z) of the switch module (1); when the switch module (1) is turned off, the absorption circuit (2) is used to make the current of the input port A or the output port B flow into the capacitor (C), and the capacitor (C) absorbs the inductance energy of the circuit; while the diodes (D) connected to the N line can precharge the capacitor (C), so that the capacitor (C) always maintains a relatively stable voltage.

[0015] An AC electronic switching device of the present invention includes a discharge circuit (3) comprising one or more discharge resistors (12) for releasing the energy stored in a capacitor (C); and a semiconductor switch (13) or a mechanical switch (14) connected in series with the discharge resistor (12). The two ends of the series circuit are respectively connected to the positive (+) and negative (-) terminals of the absorption circuit (2) for controlling the on / off state of the discharge resistor (12).

[0016] An AC electronic switch device of the present invention may further include a switch module (6), which includes a power input port A and an output port B. The switch module is used to open or close the AC current path between the input port A and the output port B.

[0017] It also includes an absorption circuit (7), which is connected to the input port A, output port B and power supply N line of the switch module (6). The absorption circuit (7) contains a capacitor that can store electrical energy, which is used to absorb the electrical energy in the loop inductance during the turn-off process of the switch module (6).

[0018] It also includes a discharge circuit (8), which is connected to the positive (+) and negative (-) terminals of the absorption circuit (7) to protect the absorption circuit (7) and the switching module (6) from damage due to excessive voltage;

[0019] It also includes a controller (16), which is connected to the switch module (6), absorption circuit (7), and discharge circuit (8) by signal connection; the controller (16) performs on / off operation on the switch module (6) according to the received external switch operation signal. At the same time, the controller (16) detects the positive (+) and negative (-) terminal voltage of the absorption circuit (7). When the voltage exceeds a set value, it issues a discharge command to the discharge circuit (8) until the positive (+) and negative (-) terminal voltage of the absorption circuit (7) does not exceed the set value.

[0020] An AC electronic switching device of the present invention includes a switching module (6) comprising a series-connected semiconductor switching device (9), the two ends of which are respectively connected to an input port A and an output port B; the series-connected semiconductor switching device (9) is used to cut off or connect the bidirectional current flowing between the input port A and the output port B, and the semiconductor switching device (9) may be one of a reverse-conducting power semiconductor device IGBT, MOSFET, or IGCT.

[0021] An AC electronic switching device of the present invention includes a switching module (1) comprising a semiconductor switching device (11) connected in reverse parallel, the two ends of which are respectively connected to an input port A and an output port B; the semiconductor switching device (11) is used to cut off or connect the bidirectional current flowing between the input port A and the output port B, and the semiconductor switching device (11) may be one of a reverse-blocking power semiconductor device IGBT, MOSFET, or IGCT.

[0022] An AC electronic switch device of the present invention includes an absorption circuit (2) comprising three sets of diodes connected in series with positive and negative terminals. The midpoint of each set of diodes connected in series is connected to the input port A, the output port B, and the power supply N line, respectively. The positive terminals of the three sets of diodes connected in series with positive and negative terminals are connected to one end of a capacitor (C), and the negative terminals of the three sets of diodes connected in series with positive and negative terminals are connected to the other end of a capacitor (C). When the switch module (6) is turned off, the diodes connected in series with positive and negative terminals can cause the currents of the input port A and the output port B to flow into the capacitor (C), so that the capacitor (C) can absorb the inductance energy of the circuit. The diodes connected in series with positive and negative terminals connected to the N line can precharge the capacitor (C), so that the capacitor (C) always maintains a relatively stable voltage.

[0023] An AC electronic switching device of the present invention includes a discharge circuit (8) comprising one or more discharge resistors (12) for releasing the energy stored in a capacitor (C); a semiconductor switch (13) or a mechanical switch (14) connected in series with the discharge resistor (12), the two ends of which are respectively connected to the positive (+) and negative (-) terminals of the absorption circuit (2) for controlling the on / off state of the discharge resistor (12). Attached Figure Description

[0024] Figure 1 This is an existing AC electronic switch circuit diagram that uses thyristors.

[0025] Figure 2 It is an existing AC electronic switch circuit diagram.

[0026] Figure 3 It is another type of existing AC electronic switch circuit diagram.

[0027] Figure 4 This is a schematic block diagram of an embodiment of an AC electronic switch device according to the present invention.

[0028] Figure 5 This is a first embodiment diagram of the switching module and absorption circuit of the present invention.

[0029] Figure 6 This is a second embodiment diagram of the switching module and absorption circuit of the present invention.

[0030] Figure 7 A schematic diagram of another embodiment of the AC electronic switch device of the present invention.

[0031] Figure 8 This is a first embodiment of another switching module and absorption circuit of the present invention.

[0032] Figure 9 This is a second embodiment of another switching module and absorption circuit of the present invention.

[0033] Figure 10 This is a third embodiment of another switching module and absorption circuit of the present invention.

[0034] Figure 11 This is a diagram of an embodiment of the discharge circuit of the present invention.

[0035] Figure 12 This is a diagram of another embodiment of the discharge circuit of the present invention. Detailed Implementation

[0036] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0037] Figure 4 This is a schematic diagram of an embodiment of an AC electronic switch device designed in this invention. The input current flows from port A through the switch module (1) to the output port B, realizing the fast switching function. The absorption circuit (2), which is connected to ports A, B, and Z respectively, absorbs the energy generated by the inductive current in the circuit during the fast switching process and stores it in the capacitor, thereby avoiding the overvoltage induced by the fast switching of the inductive current. The discharge circuit (3), which is connected to the positive (+) and negative (-) terminals of the absorption circuit (2), is used to realize the discharge protection of overvoltage. The controller (15) is connected to the switch module (1), the absorption circuit (2), and the discharge circuit (3) by signal. The controller (15) performs the switching operation on the switch module (1) according to the received external switch operation signal. At the same time, the controller (15) detects the voltage of the positive (+) and negative (-) terminals of the absorption circuit (2). When the voltage exceeds a set value, it issues a discharge command to the discharge circuit (3) until the voltage of the positive (+) and negative (-) terminals of the absorption circuit (2) decreases to no more than the set value.

[0038] Figure 5 , Figure 6 These are two embodiments of the switching module and absorption circuit of the present invention. The two semiconductor switching devices connected in reverse series constitute an AC switching circuit. Figure 5 The semiconductor switch is a common-source connection, while Figure 6 The semiconductor switch is a common-drain connection, and the connection point of two semiconductor switches forms the midpoint port (Z). In the figure, one end of each of the three diodes (D) is connected to the input port A, the output port B, and the power supply N line, respectively, while the other end of each of the three diodes (D) is connected to a capacitor (C). The other end of the capacitor (C) is connected to the midpoint port (Z). The two ends of the capacitor (C) form the positive (+) and negative (-) terminals of the absorption circuit (2). Its working process is that when the switch module (1) is turned off, the absorption circuit (2) causes the current of the input port A or the output port B to flow into the capacitor (C) through the diode, and the capacitor (C) absorbs the inductance energy of the circuit; while the diode (D) connected to the N line can precharge the capacitor (C), so that the capacitor (C) always maintains a relatively stable voltage, can quickly absorb energy, and realize fast current turn-off. The semiconductor switching device (4) can be one of the reverse-conducting power semiconductor devices IGBT, MOSFET, or IGCT.

[0039] Figure 7 This is a block diagram illustrating the principle of another embodiment of the AC electronic switch device of the present invention. The input current flows from port A through the switch module (6) to the output port B, realizing the fast switching function. The absorption circuit (7) connected to ports A and B respectively absorbs the energy generated by the inductive current in the circuit during the fast switching process and stores it in the capacitor, thereby avoiding the overvoltage induced by the fast switching of the inductive current. The discharge circuit (8) connected to the positive (+) and negative (-) terminals of the absorption circuit (7) is used to realize the discharge protection of overvoltage. The controller (16) is connected to the switch module (6), the absorption circuit (7), and the discharge circuit (8) by signal. The controller (16) performs the switching operation on the switch module (6) according to the received external switch operation signal. At the same time, the controller (16) detects the voltage of the positive (+) and negative (-) terminals of the absorption circuit (7). When the voltage exceeds a set value, it issues a discharge command to the discharge circuit (8) until the voltage of the positive (+) and negative (-) terminals of the absorption circuit (7) decreases to no more than the set value.

[0040] Figure 8 , Figure 9 These are two embodiment diagrams of the switching module (6) and absorption circuit (7) of the present invention. The two semiconductor switching devices connected in reverse series in the diagrams constitute an AC switching circuit. Figure 8 The semiconductor switch is a common-source connection, while Figure 9The semiconductor switch is a common-drain connection. The figure includes three sets of diodes (D) connected in series in pairs. The midpoint of each set of series diodes is connected to the input port A, the output port B, and the power supply N line, respectively. The positive and negative terminals of each set of series diodes (D) are connected to the two ends of the capacitor (C). The two ends of the capacitor (C) form the positive (+) and negative (-) terminals of the absorption circuit (2). Its working process is that when the switch module (6) is turned off, the absorption circuit (7) causes the current of the input port A or the output port B to flow into the capacitor (C) through the diodes, and the capacitor (C) absorbs the inductance energy of the circuit. The two diodes (D) connected to the N line can precharge the capacitor (C), so that the capacitor (C) always maintains a relatively stable voltage, can quickly absorb energy, and realize fast current turn-off. The semiconductor switching device (9) can be one of the reverse-conducting power semiconductor devices IGBT, MOSFET, or IGCT.

[0041] Figure 10 This is a third embodiment of the switching module and absorption circuit of the present invention. The device constituting the switching module (6) is composed of two semiconductor switching devices connected in reverse parallel, and the semiconductor switching devices are one type of reverse-blocking power semiconductor device, such as IGBT, MOSFET, or IGCT.

[0042] Figure 11 , Figure 12 These are two embodiments of the discharge circuit of the present invention, which includes a discharge resistor (12) and a semiconductor switch (13) or mechanical switch (14) connected in series with it. The two ends of the series circuit are connected in parallel with the positive (+) and negative (-) terminals of the absorption circuit, respectively. When the semiconductor switch (13) or mechanical switch (14) is turned on, the capacitor (C) discharges through the discharge resistor (12), and the DC terminal voltage decreases. When the semiconductor switch (13) or mechanical switch (14) is turned off, there is no current in the discharge resistor (12), and the DC terminal voltage of the capacitor (C) remains unchanged.

[0043] The above are merely preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be considered as limitations on the present invention, and the scope of protection of the present invention should be determined by the scope defined in the claims. For those skilled in the art, several improvements and modifications can be made without departing from the spirit and scope of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An AC electronic switching device, characterized in that: It includes: A switch module (1) includes a power input port A, an output port B and a midpoint port (Z), the switch module being used to open or close the AC current path between the input port A and the output port B; An absorption circuit (2) is connected to the input port A, output port B, midpoint port (Z) and power supply line N of the switch module (1). The absorption circuit (2) contains a capacitor that can store electrical energy, which is used to absorb the electrical energy in the loop inductance during the turn-off process of the switch module (1). A discharge circuit (3) is connected to the positive (+) and negative (-) terminals of the absorption circuit (2) to protect the absorption circuit (2) and the switching module (1) from damage due to excessive voltage. A controller (15) is connected to the switch module (1), the absorption circuit (2), and the discharge circuit (3) by signal connection. The controller (15) performs on / off operation on the switch module (1) according to the received external switch operation signal. At the same time, the controller (15) detects the positive (+) and negative (-) terminal voltage of the absorption circuit (2). When the voltage exceeds a set value, it issues a discharge command to the discharge circuit (3) until the positive (+) and negative (-) terminal voltage of the absorption circuit (2) does not exceed the set value. The absorption circuit (2) includes: three diodes (D) with one end connected to the input port A, the output port B and the power supply N line respectively, the other end of the three diodes (D) being connected to a capacitor (C), and the other end of the capacitor (C) being connected to the midpoint port (Z) of the switching module (1); When the switch module (1) is turned off, the absorption circuit (2) is used to make the current of the input port A or the output port B flow into the capacitor (C), and the capacitor (C) absorbs the energy of the circuit inductance; while the diode (D) connected to the N line can precharge the capacitor (C) so that the capacitor (C) always maintains a relatively stable voltage. The discharge circuit (3) includes: one or more discharge resistors (12) for releasing the energy stored in the capacitor (C); A semiconductor switch (13) or a mechanical switch (14) is connected in series with the discharge resistor (12). The two ends of the series circuit are respectively connected to the positive (+) and negative (-) terminals of the absorption circuit (2) to control the on / off state of the discharge resistor (12).

2. The AC electronic switching device according to claim 1, characterized in that: The switch module (1) includes: The reverse common-source series semiconductor switching device (4) has its two ends connected to the input port A and the output port B respectively, and its midpoint is connected to the midpoint port (Z) and to the absorption circuit (2); The reverse common-source series-connected semiconductor switching device (4) is used to cut off or connect the bidirectional current flowing between the input port A and the output port B. The reverse common-source series-connected semiconductor switching device (4) is a type of reverse-conducting power semiconductor device, such as IGBT, MOSFET, or IGCT.

3. The AC electronic switching device according to claim 1, characterized in that: The switch module (1) includes: A reverse common-drain series semiconductor switch (5) is connected at both ends to the input port A and the output port B respectively, with its midpoint connected to the midpoint port (Z) and connected to the absorption circuit (2); The reverse common-drain series-connected semiconductor switching device (5) is used to cut off or connect the bidirectional current flowing between the input port A and the output port B. The reverse common-drain series-connected semiconductor switching device (5) is a type of reverse-conducting power semiconductor device, such as IGBT, MOSFET, or IGCT.

4. An AC electronic switching device, characterized in that: It includes: A switching module (6) includes a power input port A and an output port B, the switching module being used to open or close the AC current path between the input port A and the output port B; An absorption circuit (7) is connected to the input port A, output port B and power supply N line of the switch module (6). The absorption circuit (7) contains a capacitor that can store electrical energy, which is used to absorb the electrical energy in the loop inductance during the turn-off process of the switch module (6). A discharge circuit (8) is connected to the positive (+) and negative (-) terminals of the absorption circuit (7) to protect the absorption circuit (7) and the switching module (6) from damage due to excessive voltage. A controller (16) is connected to the switch module (6), the absorption circuit (7), and the discharge circuit (8) by signal connection. The controller (16) performs on / off operation on the switch module (6) according to the received external switch operation signal. At the same time, the controller (16) detects the voltage of the positive (+) and negative (-) terminals of the absorption circuit (7). When the voltage exceeds a set value, it issues a discharge command to the discharge circuit (8) until the voltage of the positive (+) and negative (-) terminals of the absorption circuit (7) does not exceed the set value. The absorption circuit (2) includes: three sets of diodes connected in series with positive and negative terminals. The midpoint of each set of diodes connected in series is connected to the input port A, the output port B and the power supply N line respectively. The positive terminals of the three sets of diodes connected in series with positive and negative terminals are connected to one end of a capacitor (C) and the negative terminals of the three sets of diodes connected in series with positive and negative terminals are connected to the other end of a capacitor (C). When the switch module (6) is turned off, the diode connected in series with the positive and negative terminals can make the current of both the input port A and the output port B flow into the capacitor (C), so that the capacitor (C) can absorb the energy of the circuit inductance; while the diode connected in series with the positive and negative terminals connected to the N line can precharge the capacitor (C), so that the capacitor (C) always maintains a relatively stable voltage. The discharge circuit (8) includes: One or more discharge resistors (12) are used to release the energy stored in the capacitor (C); A semiconductor switch (13) or a mechanical switch (14) is connected in series with the discharge resistor (12). The two ends of the series circuit are respectively connected to the positive (+) and negative (-) terminals of the absorption circuit (2) to control the on / off state of the discharge resistor (12).

5. An AC electronic switching device according to claim 4, characterized in that: The switch module (6) includes: A series-reverse semiconductor switching device (9) is connected at both ends to input port A and output port B, respectively; The reverse-connected semiconductor switching device (9) is used to cut off or connect the bidirectional current flowing between the input port A and the output port B. The reverse-connected semiconductor switching device (9) is a type of reverse-conducting power semiconductor device, such as IGBT, MOSFET, or IGCT.

6. An AC electronic switching device according to claim 4, characterized in that: The switch module (1) includes: A semiconductor switching device (11) connected in reverse parallel has its two ends connected to the input port A and the output port B, respectively; The anti-parallel semiconductor switching device (11) is used to cut off or connect the bidirectional current flowing between the input port A and the output port B. The anti-parallel semiconductor switching device (11) is a type of reverse-blocking power semiconductor device, such as IGBT, MOSFET, or IGCT.

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