Power conversion device and uninterruptible power supply

Abstract

The embodiment of the invention discloses a power conversion device and an uninterruptible power supply, relates to the technical field of power electronics, and solves the problems of how to shorten the action time of a relay, simple structure and low cost. The power conversion device comprises an inverter circuit, a switch, a first resistor, a first switching tube, a second switching tube and an auxiliary power supply. The positive input end of the inverter circuit is connected with the positive direct-current bus, and the negative input end of the inverter circuit is connected with the negative direct-current bus. The switch comprises a coil, a moving contact and a static contact, the moving contact and the static contact are connected with the output end of the inverter circuit and the output end of the power conversion device respectively, and the coil is used for driving the moving contact and the static contact to act mutually. The first end of the first switch tube is connected with the grounding end. The coil and the first resistor are connected in series between the output end of the auxiliary power supply and the second end of the first switch tube. The second switch tube is connected in parallel with the first resistor.

Description

Technical Field

[0001] The present application relates to the field of power electronics technology, and in particular to a power conversion device and an uninterruptible power supply. Background Art

[0002] An uninterruptible power supply (UPS) or a photovoltaic inverter includes an inverter circuit and a relay connected to the output end of the inverter circuit, and the relay is used as an output switch of the inverter circuit. When the relay operates slowly, an acceleration drive circuit of the relay can be set in the uninterruptible power supply or the photovoltaic inverter to shorten the operating time of the relay.

[0003] However, the current relay acceleration drive circuit is suitable for accelerating low-power relays. When the relay acceleration drive circuit is used for accelerating high-power relays, the volume of the device needs to be increased, which will lead to a complex structure and high cost of the relay acceleration drive circuit, which in turn leads to a complex structure and high cost of the uninterruptible power supply or photovoltaic inverter. How to shorten the action time of the relay and make it simple in structure and low in cost has become an urgent problem to be solved. Summary of the invention

[0004] The embodiments of the present application provide a power conversion device and an uninterruptible power supply, which solve the problem of how to shorten the action time of a relay and have a simple structure and low cost.

[0005] In order to achieve the above purpose, the embodiment of the present application adopts the following technical solution:

[0006] In a first aspect of an embodiment of the present application, a power conversion device is provided, which includes an inverter circuit, a switch, a first resistor, a first switch tube, a second switch tube and an auxiliary power supply. The positive input terminal of the inverter circuit is connected to the positive DC bus, the negative input terminal of the inverter circuit is connected to the negative DC bus, the switch includes a coil, a moving contact and a static contact, the moving contact and the static contact are respectively connected to the output terminal of the inverter circuit and the output terminal of the power conversion device, and the coil is used to drive the moving contact and the static contact to move each other. The first end of the first switch tube is connected to the ground terminal, and the coil and the first resistor are connected in series between the output terminal of the auxiliary power supply and the second end of the first switch tube. The second switch tube is connected in parallel with the first resistor.

[0007] Based on this solution, the first end of the first switch tube is connected to the ground end, the coil and the first resistor are connected in series between the output end of the auxiliary power supply and the second end of the first switch tube, and the second switch tube is connected in parallel with the first resistor. When the first switch tube is controlled to be turned on, the auxiliary power supply supplies power to the coil through the first resistor. When the switch action is slow, the first resistor is short-circuited by controlling the second switch tube to be turned on, so that the auxiliary power supply supplies power to the coil through the second switch tube. Since there is no first resistor voltage divider, the voltage provided by the auxiliary power supply to the coil can be increased, the action of the switch can be accelerated, and the action time of the switch can be shortened. Compared with the relay acceleration drive circuit in the prior art, in the power conversion device provided by the embodiment of the present application, fewer devices are used when accelerating the action of the switch, and when used to accelerate the high-power switch, there is no need to increase the volume of the device. A large-volume capacitor is used, the structure is simpler, the cost is lower, and the power density of the power conversion device can be improved.

[0008] In combination with the first aspect, in a possible implementation, the power conversion device further includes a controller for controlling the first switch tube and the second switch tube to be turned on simultaneously, and controlling the duration of the second switch tube to be turned on to be greater than or equal to the action time of the switch.

[0009] In a possible embodiment, the action time of the above switch is equal to the time required for the switch to complete the action when the first switch tube and the second switch tube are both turned on, the first resistor is short-circuited, and the auxiliary power supply supplies power to the coil through the second switch tube.

[0010] Based on this solution, when the controller needs to control the switch action and needs to speed up the switch action and shorten the switch action time, the controller simultaneously controls the first switch tube and the second switch tube to be turned on, which can short-circuit the first resistor, and the auxiliary power supply can provide a larger voltage to the coil through the second switch tube, which can speed up the switch action and shorten the switch action time. The conduction time of the second switch tube is controlled to be greater than or equal to the switch action time, thereby ensuring that the switch action is accelerated during the switch action.

[0011] In combination with the first aspect, in a possible implementation manner, the controller controls the second switch tube to be turned on for a duration greater than or equal to an action time of the switch and less than or equal to a preset threshold.

[0012] Based on this solution, the controller controls the conduction time of the second switch tube to be greater than or equal to the action time of the switch and less than or equal to the preset threshold. When the conduction time of the second switch tube is controlled to be greater than the preset threshold, the controller controls the second switch tube to be turned off, so that the auxiliary power supply supplies power to the coil through the first resistor. At this time, the current in the circuit is small, thereby reducing the loss of the coil.

[0013] In combination with the first aspect, in a possible implementation, the power conversion device further includes a second resistor disposed between the controlled end of the second switch tube and the source or emitter of the second switch tube, and a third resistor and a first capacitor connected in series. The controller is used to control the first switch tube to be turned on so that the auxiliary power supply charges the first capacitor, and adjust the voltage of the controlled end of the second switch tube to turn on the second switch tube, and the turn-on time of the second switch tube is related to the resistance value of the second resistor, the resistance value of the third resistor, and the capacitance value of the first capacitor.

[0014] Based on this solution, the controller can control the first switch tube to be turned on so that the auxiliary power supply charges the first capacitor, and adjust the voltage of the controlled end of the second switch tube to turn on the second switch tube. The auxiliary power supply provides a larger voltage to the coil through the second switch tube, thereby speeding up the action of the switch and shortening the action time of the switch. The on-time of the second switch tube is related to the resistance value of the second resistor, the resistance value of the third resistor and the capacitance value of the first capacitor. By adjusting the resistance value of the second resistor, the resistance value of the third resistor and the capacitance value of the first capacitor, the on-time of the second switch tube can be adjusted to be greater than or equal to the action time of the switch, and less than or equal to the preset threshold value, so that after the switch action, the second switch tube can be turned off, and the auxiliary power supply supplies power to the coil through the first resistor. At this time, the current in the circuit is small, which can reduce the loss of the coil.

[0015] In combination with the first aspect, in a possible implementation, the second switch tube is a PMOS or PNP transistor. One end of the first resistor is connected to the output end of the auxiliary power supply, one end of the coil is connected to the second end of the first switch tube, and the other end of the coil is connected to the other end of the first resistor. The third resistor and the first capacitor are connected in series between the controlled end of the second switch tube and the second end of the first switch tube.

[0016] Based on this solution, the controller can control the first switch tube to be turned on so that the auxiliary power supply charges the first capacitor, and adjust the voltage of the controlled end of the second switch tube to turn on the second switch tube. The auxiliary power supply provides a larger voltage to the coil through the second switch tube, thereby speeding up the action of the switch and shortening the action time of the switch. The on-time of the second switch tube is related to the resistance value of the second resistor, the resistance value of the third resistor and the capacitance value of the first capacitor. By adjusting the resistance value of the second resistor, the resistance value of the third resistor and the capacitance value of the first capacitor, the on-time of the second switch tube can be adjusted to be greater than or equal to the action time of the switch, and less than or equal to the preset threshold value, so that after the switch action, the second switch tube can be turned off, and the auxiliary power supply supplies power to the coil through the first resistor. At this time, the current in the circuit is small, which can reduce the loss of the coil.

[0017] In combination with the first aspect, in a possible implementation, the power conversion device also includes a first diode, an anode of the first diode is connected to the controlled end of the second switch tube, and a cathode of the first diode is connected to the source or emitter of the second switch tube.

[0018] Based on this solution, by setting the first diode, when the controller controls the first switch tube to turn on, the first capacitor is charged, and after the switch is actuated, the controller controls the first switch tube to turn off, the first capacitor discharges through the first diode and the third resistor without passing through the second resistor, thereby avoiding that when the first capacitor is discharged, a higher voltage is applied between the controlled end of the second switch tube and the source or emitter of the second switch tube, thereby avoiding damage to the second switch tube, and improving the reliability of the power conversion device. At the same time, the RCD buffer circuit composed of the first capacitor, the third resistor, the first diode and the first resistor can absorb the peak voltage generated by the back electromotive force in the coil, can protect the first switch tube and the second switch tube, and can improve the reliability of the power conversion device.

[0019] In combination with the first aspect, in a possible implementation, the second switch tube is an NMOS or NPN transistor. One end of the coil is connected to the output end of the auxiliary power supply, one end of the first resistor is connected to the second end of the first switch tube, and the other end of the coil is connected to the other end of the first resistor. The third resistor and the first capacitor are connected in series between the output end of the auxiliary power supply and the controlled end of the second switch tube.

[0020] Based on this solution, the controller can control the first switch tube to be turned on so that the auxiliary power supply charges the first capacitor, and adjust the voltage of the controlled end of the second switch tube to turn on the second switch tube. The auxiliary power supply provides a larger voltage to the coil through the second switch tube, thereby speeding up the action of the switch and shortening the action time of the switch. The on-time of the second switch tube is related to the resistance value of the second resistor, the resistance value of the third resistor and the capacitance value of the first capacitor. By adjusting the resistance value of the second resistor, the resistance value of the third resistor and the capacitance value of the first capacitor, the on-time of the second switch tube can be adjusted to be greater than or equal to the action time of the switch, and less than or equal to the preset threshold value, so that after the switch action, the second switch tube can be turned off, and the auxiliary power supply supplies power to the coil through the first resistor. At this time, the current in the circuit is small, which can reduce the loss of the coil.

[0021] In combination with the first aspect, in a possible implementation, the power conversion device also includes a first diode, a cathode of the first diode is connected to the controlled end of the second switch tube, and an anode of the first diode is connected to the source or emitter of the second switch tube.

[0022] Based on this solution, by setting the first diode, when the controller controls the first switch tube to turn on, the first capacitor is charged, and after the switch is actuated, the controller controls the first switch tube to turn off, the first capacitor discharges through the first diode and the third resistor without passing through the second resistor, thereby avoiding that when the first capacitor is discharged, a higher voltage is applied between the controlled end of the second switch tube and the source or emitter of the second switch tube, thereby avoiding damage to the second switch tube, and improving the reliability of the power conversion device. At the same time, the RCD buffer circuit composed of the first capacitor, the third resistor, the first diode and the first resistor can absorb the peak voltage generated by the back electromotive force in the coil, can protect the first switch tube and the second switch tube, and can improve the reliability of the power conversion device.

[0023] In combination with the first aspect, in a possible implementation, the power conversion device further includes a voltage regulator diode and a second diode. The cathode of the voltage regulator diode is connected to the cathode of the second diode, the anode of the voltage regulator diode is connected to one end of the coil current input, and the anode of the second diode is connected to one end of the coil current output. Alternatively, the anode of the voltage regulator diode is connected to the anode of the second diode, the cathode of the second diode is connected to one end of the coil current input, and the cathode of the voltage regulator diode is connected to one end of the coil current output.

[0024] Based on the present solution, by setting a voltage-stabilizing diode and a second diode, when the controller controls the first switch tube to turn on, the first capacitor is charged, and after the switch is actuated, the controller controls the first switch tube to turn off, the voltage-stabilizing diode is used to absorb the peak voltage generated by the back electromotive force in the coil, thereby protecting the first switch tube and the second switch tube, thereby improving the reliability of the power conversion device, and the second diode is used to ensure the unidirectional flow of current, prevent reverse voltage shock, and avoid short circuit of the auxiliary power supply, thereby improving the reliability of the power conversion device.

[0025] In combination with the first aspect, in a possible implementation, the power conversion device further includes a second capacitor, a fourth resistor and a second diode, and the second capacitor and the fourth resistor are connected in parallel. One end of the second capacitor and the fourth resistor connected in parallel is connected to the anode of the second diode, the cathode of the second diode is connected to one end of the coil current input, and the other end of the second capacitor and the fourth resistor connected in parallel is connected to one end of the coil current output. Alternatively, one end of the second capacitor and the fourth resistor connected in parallel is connected to the cathode of the second diode, the other end of the second capacitor and the fourth resistor connected in parallel is connected to one end of the coil current input, and the anode of the second diode is connected to one end of the coil current output.

[0026] Based on this solution, by setting the second capacitor, the fourth resistor and the second diode, when the controller controls the first switch tube to turn on, the first capacitor is charged, and after the switch is actuated, the controller controls the first switch tube to turn off, the RCD buffer circuit composed of the second capacitor, the fourth resistor and the second diode can absorb the peak voltage generated by the back electromotive force in the coil, can protect the first switch tube and the second switch tube, and can improve the reliability of the power conversion device. At the same time, the second diode is used to ensure the unidirectional flow of current, prevent reverse voltage shock, and avoid auxiliary power supply short circuit, which can improve the reliability of the power conversion device.

[0027] In a second aspect of the embodiments of the present application, an uninterruptible power supply is provided, the uninterruptible power supply includes a main circuit, a bypass and a load end, the main circuit and the bypass are both used to supply power to the load end. A rectifier circuit and a power conversion device are provided on the main circuit, the input end of the rectifier circuit is connected to the input end of the uninterruptible power supply, the output end of the rectifier circuit is connected to the input end of the power conversion device, the output end of the power conversion device is connected to the load end, the load end is used to connect the load, and the power conversion device is the power conversion device as described in the first aspect or any possible implementation of the first aspect.

[0028] The description of the second aspect in this application can refer to the detailed description of the first aspect; and the beneficial effects of the second aspect can refer to the analysis of the beneficial effects of the first aspect, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A circuit topology diagram of an uninterruptible power supply;

[0030] Figure 2 A schematic diagram of a circuit topology of a power conversion device provided in an embodiment of the present application;

[0031] Figure 3 A schematic diagram of a circuit topology of another power conversion device provided in an embodiment of the present application;

[0032] Figure 4 A circuit topology diagram of another power conversion device provided in an embodiment of the present application;

[0033] Figure 5 A schematic diagram of a circuit topology of another power conversion device provided in an embodiment of the present application;

[0034] Figure 6 A schematic diagram of a circuit topology of a photovoltaic inverter provided in an embodiment of the present application. DETAILED DESCRIPTION

[0035] The following will discuss the making and use of each embodiment in detail. However, it should be understood that many applicable inventive concepts provided by this application can be implemented in a variety of specific environments. The specific embodiments discussed are only used to illustrate the specific ways to implement and use this description and this technology, and do not limit the scope of this application.

[0036] Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art.

[0037] Various circuits or other components may be described or referred to as being "configured to" perform one or more tasks. In this case, "configured to" is used to imply structure by indicating that the circuit / component includes structure (e.g., circuitry) that performs the one or more tasks during operation. Thus, even when the specified circuit / component is not currently operational (e.g., not turned on), the circuit / component may be referred to as being configured to perform the task. Circuits / components used with the phrase "configured to" include hardware, such as circuits that perform an operation, etc.

[0038] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application. In the embodiments of the present application, words such as "first" and "second" do not limit the quantity and order. In the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "exemplary" or "for example" in the present application should not be interpreted as being more preferred or more advantageous than other embodiments or design. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a concrete way.

[0039] Before introducing the embodiments of the present application, the technical terms and background technologies involved in the present application are first introduced.

[0040] Silicon controlled rectifier (SCR): It can be referred to as thyristor or thyristor. It can be used as a switch in the circuit. It has the advantages of small size, high efficiency and long life. The types of thyristors include unidirectional thyristors and triple alternating current semiconductor switches (Triac). The triac can also be called bidirectional thyristors. The bidirectional thyristors can be used to replace two unidirectional thyristors connected in parallel with opposite polarity (also called two unidirectional thyristors connected in reverse parallel).

[0041] Zener diode: It can also be called a voltage-stabilizing diode. It refers to a diode that uses the reverse breakdown state of a PN junction to stabilize the voltage while allowing the current to vary over a wide range while the voltage remains essentially unchanged.

[0042] Time constant (tau, τ): is a parameter that describes the charging or discharging rate of a capacitor. The time constant is the product of capacitance (C) and resistance (R).

[0043] RCD snubber circuit: a protection circuit that includes a resistor (R), a capacitor (C) and a diode (D) to absorb the peak voltage generated by the back electromotive force in the coil when the switch device is turned off, thereby protecting the switch device from damage. The diode D in the RCD snubber circuit is used to ensure the unidirectional flow of current and prevent reverse voltage shock.

[0044] Uninterruptible power supplies are used to provide uninterrupted power to loads that require high power stability. This uninterruptible power supply is widely used in data centers, medical equipment, industrial automation, communication equipment and other fields to provide stable and uninterrupted power supply for key equipment.

[0045] like Figure 1 The figure shows a circuit topology diagram of an uninterruptible power supply 100. The uninterruptible power supply 100 includes a main circuit 110, a bypass circuit 120 and a load end. The main circuit 110 is used to connect to a first input power supply 210, and the bypass circuit 120 is used to connect to a second input power supply 220. Both the main circuit 110 and the bypass circuit 120 are used to supply power to the load end, and the load end is used to connect to a load 300 to supply power to the load 300. The main circuit 110 is provided with a rectifier circuit 111, an inverter circuit 112 and a relay 113. The input end of the rectifier circuit 111 is used to connect to the first input power supply 210, the output end of the rectifier circuit 111 is connected to a positive DC bus BUS+ and a negative DC bus BUS-, the input end of the inverter circuit 112 is connected to a positive DC bus BUS+ and a negative DC bus BUS-, and the relay 113 is provided between the output end of the inverter circuit 112 and the load end, and the relay 113 is used to serve as an output switch of the inverter circuit 112.

[0046] Reference Figure 1The main circuit 110 in the uninterruptible power supply 100 also includes positive and negative bus capacitors arranged between the positive DC bus BUS+ and the negative DC bus BUS-, and the positive and negative bus capacitors include a first bus capacitor Ca and a second bus capacitor Cb connected in series, and the connection point of the first bus capacitor Ca and the second bus capacitor Cb is connected to the neutral wire (neutral wire, N). The inverter circuit 112 includes a first switch tube Q1 and a second switch tube Q2 connected in series between the positive DC bus BUS+ and the negative DC bus BUS-, and the connection point of the first switch tube Q1 and the second switch tube Q2 is the output end of the inverter circuit 112. The relay 113 includes a coil L and a main contact assembly M, and the main contact assembly M includes a moving contact M1 and a stationary contact M2. The coil L is used to drive the moving contact M1 and the stationary contact M2 to act mutually, and the moving contact M1 and the stationary contact M2 are respectively connected to the output end and the load end of the inverter circuit 112. The inverter circuit 112 is used to convert direct current into alternating current, and provide power to the load 300 through the relay 113 .

[0047] Since relay 113 has no arc extinguishing function, refer to Figure 1 A first unidirectional thyristor SCR1 and a second unidirectional thyristor SCR2 connected in reverse parallel may be provided in the main circuit 110. The first unidirectional thyristor SCR1 and the second unidirectional thyristor SCR2 connected in reverse parallel are connected in parallel with the relay 113. The first unidirectional thyristor SCR1 and the second unidirectional thyristor SCR2 assist the relay 113, thereby avoiding arcing and sticking of the relay 113.

[0048] In one power frequency cycle, the first unidirectional thyristor SCR1 and the second unidirectional thyristor SCR2 are each turned on for half of the power frequency cycle. The thyristor (the first unidirectional thyristor SCR1 or the second unidirectional thyristor SCR2) has a strong surge resistance capability in half of the power frequency cycle. When it exceeds one power frequency cycle, the surge resistance capability of the thyristor is rapidly weakened. Therefore, the action time of the relay 113 needs to be limited to one power frequency cycle. When the relay action is slow, the relay acceleration drive circuit can be set in the uninterruptible power supply 100 to shorten the action time of the relay.

[0049] Reference Figure 1 The main circuit 110 may also include a relay acceleration drive circuit 114 and an auxiliary power supply 115. The relay acceleration drive circuit 114 includes a metal-oxide-semiconductor field-effect transistor (MOSFET) MOS, a PNP-type transistor Q, a capacitor C, a first diode D1, a second diode D2, a first resistor R1, a second resistor R2, a third resistor R3 and a Zener diode ZD.

[0050] Reference Figure 1 , the first end of the metal oxide semiconductor field effect transistor MOS is connected to the ground terminal (ground, G), the second end of the metal oxide semiconductor field effect transistor MOS is connected to one end of the coil L in the relay 113 and one end of the first resistor R1, and the other end of the coil L is connected to one end of the second resistor R2 and the anode of the voltage stabilizing diode ZD. The other end of the first resistor R1 is connected to the controlled end base of the PNP transistor Q. The other end of the second resistor R2 is connected to the cathode of the first diode D1, the emitter of the PNP transistor Q and one end of the capacitor C, the anode of the first diode D1 is connected to the output end of the auxiliary power supply 115, the collector of the PNP transistor Q and the other end of the capacitor C are connected to one end of the third resistor R3, and the other end of the third resistor R3 is connected to the ground terminal G. The cathode of the voltage stabilizing diode ZD is connected to the cathode of the second diode D2, and the anode of the second diode D2 is connected to the second end of the metal oxide semiconductor field effect transistor MOS.

[0051] Reference Figure 1 , taking the auxiliary power supply 115 outputting a +15V voltage as an example. When the metal oxide semiconductor field effect transistor MOS and the PNP transistor Q are turned off, the DC power output by the auxiliary power supply 115 passes through the first diode D1, the capacitor C and the third resistor R3 to the ground terminal G, and the auxiliary power supply 115 charges the capacitor C, and the capacitor C is charged to the +15V voltage output by the auxiliary power supply 115. When the metal oxide semiconductor field effect transistor MOS is turned on, the PNP transistor Q is turned on synchronously, and the auxiliary power supply 115 is connected in series with the capacitor C through the first diode D1 and the PNP transistor Q, and then provides a voltage to the coil L in the relay 113 through the second resistor R2, so that the coil L in the relay 113 can be provided with twice the output voltage of the auxiliary power supply 115, thereby accelerating the action of the relay 113 and shortening the action time of the relay 113. After the capacitor C is discharged, the auxiliary power supply 115 directly provides voltage to the coil L in the relay 113 through the first diode D1 and the second resistor R2. Compared with the case where the capacitor C is charged to the +15V voltage output by the auxiliary power supply 115, the auxiliary power supply 115 is connected in series with the capacitor C through the first diode D1 and the PNP transistor Q, and then provides voltage to the coil L in the relay 113 through the second resistor R2, the current in the circuit is smaller at this time, which can reduce the loss of the coil L in the relay 113. After the auxiliary power supply 115 and the capacitor C provide voltage to the coil L in the relay 113, when the metal oxide semiconductor field effect transistor MOS is turned off, the voltage regulator diode ZD is used to absorb the peak voltage generated by the back electromotive force in the coil L of the relay 113, thereby protecting the metal oxide semiconductor field effect transistor MOS and the transistor Q. The second diode D2 is used to ensure the unidirectional flow of current, prevent voltage reverse impact, and avoid the auxiliary power supply 115 from short circuit.

[0052] However, the relay acceleration drive circuit 114 is suitable for accelerating a low-power relay. When the relay acceleration drive circuit 114 is used for accelerating a high-power relay, the volume of the device needs to be increased. The use of a large-volume capacitor C will lead to a complex structure and high cost of the relay acceleration drive circuit 114, which in turn leads to a complex structure and high cost of the uninterruptible power supply 100. How to shorten the action time of the relay and make the structure simple and low-cost has become an urgent problem to be solved.

[0053] Based on this, an embodiment of the present application provides a power conversion device, which controls the switch action by controlling the first switch tube to be turned on and controlling the auxiliary power supply to supply power to the coil in the switch through a resistor. When the switch action needs to be accelerated, the second switch tube connected in parallel with the resistor is controlled to be turned on to short-circuit the resistor so that the auxiliary power supply supplies power to the coil in the switch through the second switch tube to increase the voltage provided by the auxiliary power supply to the coil in the switch, thereby accelerating the switch action and shortening the switch action time. In addition, fewer devices are used, and the power conversion device has a simple structure and lower cost.

[0054] like Figure 2 , which is a schematic diagram of a circuit topology of a power conversion device 400 provided in an embodiment of the present application. The power conversion device 400 includes an inverter circuit 410 , a switch 420 , a first resistor R1 , a first switch tube Q1 , a second switch tube Q2 and an auxiliary power supply 430 .

[0055] Reference Figure 2 The positive input terminal of the inverter circuit 410 is connected to the positive DC bus BUS+, and the negative input terminal of the inverter circuit 410 is connected to the negative DC bus BUS-. The switch 420 includes a coil L and a main contact assembly M, and the main contact assembly M includes a moving contact M1 and a stationary contact M2. The moving contact M1 and the stationary contact M2 are respectively connected to the output terminal of the inverter circuit 410 and the output terminal of the power conversion device 400. The output terminal of the power conversion device 400 is used to connect to the load 300. The coil L is used to drive the moving contact M1 and the stationary contact M2 to act on each other.

[0056] In a possible embodiment, the static contact M2 is connected to the output end of the inverter circuit 410, and the moving contact M1 is connected to the output end of the power conversion device 400, or, as Figure 2 As shown, the moving contact M1 is connected to the output end of the inverter circuit 410 , and the stationary contact M2 is connected to the output end of the power conversion device 400 , which is not limited in the embodiment of the present application.

[0057] Reference Figure 2The first end of the first switch tube Q1 is connected to the ground end G, the coil L and the first resistor R1 are connected in series between the output end of the auxiliary power supply 430 and the second end of the first switch tube Q1, and the second switch tube Q2 is connected in parallel with the first resistor R1.

[0058] In a possible embodiment, the coil L and the first resistor R1 are connected in series between the output end of the auxiliary power supply 430 and the second end of the first switch tube Q1, including: one end of the coil L is connected to the output end of the auxiliary power supply 430, the other end of the coil L is connected to one end of the first resistor R1, and the other end of the first resistor R1 is connected to the second end of the first switch tube Q1, or, as Figure 2 As shown, one end of the first resistor R1 is connected to the output end of the auxiliary power supply 430, the other end of the first resistor R1 is connected to one end of the coil L, and the other end of the coil L is connected to the second end of the first switch tube Q1, which is not limited in this embodiment of the present application.

[0059] In one possible embodiment, referring to Figure 2 The power conversion device 400 may further include a controller 440. When the controller 440 controls the first switch tube Q1 to turn on, the auxiliary power supply 430 supplies power to the coil L through the first resistor R1. When the switch 420 operates slowly, the controller 440 controls the second switch tube Q2 to turn on, short-circuiting the first resistor R1 so that the auxiliary power supply 430 supplies power to the coil L through the second switch tube Q2. Since there is no voltage division by the first resistor R1, the voltage provided by the auxiliary power supply 430 to the coil L can be increased, the operation of the switch 420 can be accelerated, and the operation time of the switch 420 can be shortened. Figure 1 Compared with the relay acceleration drive circuit 114 shown, in the power conversion device 400 provided in the embodiment of the present application, fewer devices are used when accelerating the action of the switch 420, and when the switch 420 is a high-power switch 420, there is no need to increase the volume of the device. A large-volume capacitor C is used to accelerate the action of the switch 420, which has a simpler structure and lower cost.

[0060] In a possible embodiment, the controller 440 is used to control the first switch tube Q1 and the second switch tube Q2 to be turned on at the same time, and the duration of the second switch tube Q2 being turned on is controlled to be greater than or equal to the action time of the switch 420. The embodiment of the present application does not limit the specific value of the action time of the switch 420. The action time of the above-mentioned switch 420 is equal to the time required for the switch 420 to complete the action when the first switch tube Q1 and the second switch tube Q2 are both turned on, the first resistor R1 is short-circuited, and the auxiliary power supply 430 supplies power to the coil L through the second switch tube Q2. It can be understood that when the controller 440 needs to control the action of the switch 420 and needs to speed up the action of the switch 420 and shorten the action time of the switch 420, the controller 440 simultaneously controls the first switch tube Q1 and the second switch tube Q2 to be turned on, and the first resistor R1 can be short-circuited. The auxiliary power supply 430 can provide a larger voltage to the coil L through the second switch tube Q2, which can speed up the action of the switch 420 and shorten the action time of the switch 420. The conduction time of the second switch tube Q2 is controlled to be greater than or equal to the action time of the switch 420, thereby ensuring that the action of the switch 420 is accelerated during the action of the switch 420.

[0061] In a possible embodiment, the controller 440 controls the duration of the second switch tube Q2 to be greater than or equal to the action time of the switch 420, and less than or equal to the preset threshold value. The embodiment of the present application does not limit the specific value of the preset threshold value. It can be understood that when the controller 440 controls the duration of the second switch tube Q2 to be greater than the preset threshold value, the second switch tube Q2 is turned off, so that the auxiliary power supply 430 supplies power to the coil L through the first resistor R1. At this time, the current in the circuit is small, thereby reducing the loss of the coil L.

[0062] In a possible embodiment, the type of the switch 420 includes a relay or a contactor, which is not limited in the embodiment of the present application.

[0063] In a possible embodiment, the inverter circuit 410 is a two-level, three-level or multi-level inverter circuit, which is not limited in the embodiment of the present application.

[0064] For example, the inverter circuit 410 is a two-level inverter circuit. Figure 2As shown, the power conversion device 400 also includes positive and negative bus capacitors arranged between the positive DC bus BUS+ and the negative DC bus BUS-, and the positive and negative bus capacitors include a first bus capacitor Ca and a second bus capacitor Cb connected in series, and the connection point of the first bus capacitor Ca and the second bus capacitor Cb is connected to the neutral line N. The inverter circuit 410 includes a third switch tube Q3 and a fourth switch tube Q4 connected in series between the positive DC bus BUS+ and the negative DC bus BUS-, and the connection point of the third switch tube Q3 and the fourth switch tube Q4 is the output end of the inverter circuit 410.

[0065] In a possible embodiment, the types of the first switch tube Q1 and the second switch tube Q2, and any one of the third switch Q3 and the fourth switch Q4 include triodes, insulate-gate bipolar transistors (IGBT) or metal oxide semiconductor field effect transistors, which are not limited in the embodiments of the present application.

[0066] In the power conversion device 400 provided in the embodiment of the present application, the first end of the first switch tube Q1 is connected to the ground terminal G, the coil L and the first resistor R1 are connected in series between the output end of the auxiliary power supply 430 and the second end of the first switch tube Q1, and the second switch tube Q2 is connected in parallel with the first resistor R1. When the controller 440 controls the first switch tube Q1 to be turned on, the auxiliary power supply 430 supplies power to the coil L through the first resistor R1. When the switch 420 operates slowly, the controller 440 controls the second switch tube Q2 to be turned on to short-circuit the first resistor R1, so that the auxiliary power supply 430 supplies power to the coil L through the second switch tube Q2. Since there is no voltage divider of the first resistor R1, the voltage provided by the auxiliary power supply 430 to the coil L can be increased, the operation of the switch 420 can be accelerated, and the operation time of the switch 420 can be shortened. Compared with the above Figure 1 Compared with the relay acceleration drive circuit 114 shown, in the power conversion device 400 provided in the embodiment of the present application, fewer devices are used when accelerating the action of the switch 420, and when used to accelerate the high-power switch 420, there is no need to increase the volume of the device. A large-volume capacitor C is used, which has a simpler structure and lower cost, and can improve the power density of the power conversion device 400.

[0067] In a possible embodiment, Figure 3As shown in (a), it is a circuit topology diagram of a power conversion device 400 provided in an embodiment of the present application. The power conversion device 400 provided in an embodiment of the present application also includes a second resistor R2, a third resistor R3 and a first capacitor C1. The second resistor R2 is arranged between the controlled end of the second switch tube Q2 and the source or emitter of the second switch tube Q2, and the third resistor R3 and the first capacitor C1 are connected in series. The controller 440 is used to control the first switch tube Q1 to be turned on, so that the auxiliary power supply 430 charges the first capacitor C1, and adjusts the voltage of the controlled end of the second switch tube Q2 to turn on the second switch tube Q2. The turn-on time of the second switch tube Q2 is related to the resistance value of the second resistor R2, the resistance value of the third resistor R3 and the capacitance value of the first capacitor C1. It can be understood that the controller 440 controls the first switch tube Q1 to be turned on, so that the auxiliary power supply 430 charges the first capacitor C1, adjusts the voltage of the controlled end of the second switch tube Q2, so that the second switch tube Q2 is turned on, and the auxiliary power supply 430 provides a larger voltage to the coil L through the second switch tube Q2, thereby accelerating the action of the switch 420 and shortening the action time of the switch 420. And the conduction time of the second switch tube Q2 is related to the resistance value of the second resistor R2, the resistance value of the third resistor R3 and the capacitance value of the first capacitor C1. By adjusting the resistance value of the second resistor R2, the resistance value of the third resistor R3 and the capacitance value of the first capacitor C1, the conduction time of the second switch tube Q2 can be adjusted to be greater than or equal to the action time of the switch 420, and less than or equal to the preset threshold value, so as to ensure that the action of the switch 420 is accelerated during the action of the switch 420. After the action of the switch 420, the second switch tube Q2 can be turned off, and the auxiliary power supply 430 supplies power to the coil L through the first resistor R1. At this time, the current in the circuit is small, which can reduce the loss of the coil L.

[0068] In a possible embodiment, Figure 3 As shown in (a) of FIG. 1 , the third resistor R3 and the first capacitor C1 are connected in series between the controlled end of the second switch tube Q2 and the second end of the first switch tube Q1, or, as shown in FIG. Figure 4 As shown, the third resistor R3 and the first capacitor C1 are connected in series between the output end of the auxiliary power supply 430 and the controlled end of the second switch tube Q2. The specific connection position of the third resistor R3 and the first capacitor C1 is related to the type of the second switch tube Q2. The embodiment of the present application does not limit the specific connection position of the third resistor R3 and the first capacitor C1, and does not limit the series connection sequence of the third resistor R3 and the first capacitor C1. The following is an exemplary description of possible situations.

[0069] In one possible embodiment, referring to Figure 3In (a), the first switch tube Q1 is a negative channel-Metal-Oxide-Semiconductor (NMOS), and the second switch tube Q2 is a positive channel Metal Oxide Semiconductor (PMOS). One end of the first resistor R1 is connected to the output end of the auxiliary power supply 430, one end of the coil L is connected to the second end drain of the first switch tube Q1, and the other end of the coil L is connected to the other end of the first resistor R1. The second resistor R2 is arranged between the controlled end gate of the second switch tube Q2 and the source of the second switch tube Q2. The third resistor R3 and the first capacitor C1 are connected in series between the controlled end gate of the second switch tube Q2 and the second end drain of the first switch tube Q1.

[0070] Reference Figure 3 In (a), before the controller 440 controls the first switch tube Q1 to be turned on, the voltage applied by the auxiliary power supply 430 to both ends of the first capacitor C1 is equal, and the voltage of the first capacitor C1 is 0. When the controller 440 controls the first switch tube Q1 to be turned on, the first capacitor C1 is turned on with the ground terminal G through the first switch tube Q1, and a voltage difference is generated across the first capacitor C1. The auxiliary power supply 430 charges the first capacitor C1 through the second resistor R2, and the first capacitor C1 and the third resistor R3 pull down the voltage of the gate of the controlled end of the second switch tube Q2, and the second switch tube Q2 is turned on. Compared with the auxiliary power supply 430 supplying power to the coil L through the first resistor R1, the auxiliary power supply 430 provides a larger voltage to the coil L through the second switch tube Q2, thereby accelerating the action of the switch 420 and shortening the action time of the switch 420. Among them, the conduction time of the second switch tube Q2 is related to the time constant (C1*(R3+R2)), wherein C1 represents the capacitance of the first capacitor C1, R3 represents the resistance of the third resistor R3, and R2 represents the resistance of the second resistor R2. By changing the selection of each component, the conduction time of the second switch tube Q2 can be changed. After the first capacitor C1 is fully charged, the voltages across the first capacitor C1 are equal again without a voltage difference, the second switch tube Q2 is turned off, and the auxiliary power supply 430 supplies power to the coil L through the first resistor R1. At this time, the current in the circuit is small, thereby reducing the loss of the coil L.

[0071] In one possible embodiment, referring to Figure 3(b) is a circuit topology diagram of a power conversion device 400 provided in an embodiment of the present application, in which the first switch tube Q1 is a negative channel metal oxide semiconductor field effect transistor NMOS, and the second switch tube Q2 can be a PNP type transistor. One end of the first resistor R1 is connected to the output end of the auxiliary power supply 430, one end of the coil L is connected to the second end drain of the first switch tube Q1, and the other end of the coil L is connected to the other end of the first resistor R1. The second resistor R2 is arranged between the controlled end base of the second switch tube Q2 and the emitter of the second switch tube Q2. The third resistor R3 and the first capacitor C1 are connected in series between the controlled end base of the second switch tube Q2 and the second end drain of the first switch tube Q1. Or, refer to Figure 3 (c) is a circuit topology diagram of a power conversion device 400 provided in an embodiment of the present application. The first switch tube Q1 is a negative channel metal oxide semi-conductor field effect transistor NMOS, and the second switch tube Q2 can be a Darlington transistor. In the embodiment of the present application, the Darlington transistor is used as Figure 3 The Darlington transistor shown in (c) is used as an example for illustration. When the circuit topology of the power conversion device 400 is as follows Figure 3 (b) or Figure 3 When the circuit topology of the power conversion device 400 shown in (c) is used, the working principle of the power conversion device 400 can refer to the above Figure 3 The working principle of the power conversion device 400 shown in (a) and the prior art are not repeated in the embodiments of the present application.

[0072] In a possible embodiment, Figure 4 As shown, the first switch tube Q1 is a negative channel metal oxide semi-conductor field effect transistor NMOS, and the second switch tube Q2 is a negative channel metal oxide semi-conductor field effect transistor NMOS or an NPN type triode. The embodiment of the present application takes the second switch tube Q2 as a negative channel metal oxide semi-conductor field effect transistor NMOS as an example for illustrative description. One end of the coil L is connected to the output end of the auxiliary power supply 430, one end of the first resistor R1 is connected to the second end drain of the first switch tube Q1, and the other end of the coil L is connected to the other end of the first resistor R1. The second resistor R2 is arranged between the controlled end gate of the second switch tube Q2 and the source of the second switch tube Q2. The third resistor R3 and the first capacitor C1 are connected in series between the output end of the auxiliary power supply 430 and the controlled end gate of the second switch tube Q2.

[0073] Reference Figure 4Before the controller 440 controls the first switch tube Q1 to be turned on, the voltage applied by the auxiliary power supply 430 to both ends of the first capacitor C1 is equal, and the voltage of the first capacitor C1 is 0. When the controller 440 controls the first switch tube Q1 to be turned on, the first capacitor C1 is turned on with the ground terminal G through the third resistor R3, the second resistor R2 and the first switch tube Q1, and a voltage difference is generated across the first capacitor C1. The auxiliary power supply 430 charges the first capacitor C1, and the first switch tube Q1 pulls down the voltage of the source or emitter of the second switch tube Q2. The first capacitor C1 and the third resistor R3 pull up the voltage of the gate of the controlled end of the second switch tube Q2, and the second switch tube Q2 is turned on. Compared with the auxiliary power supply 430 supplying power to the coil L through the first resistor R1, the auxiliary power supply 430 provides a larger voltage to the coil L through the second switch tube Q2, thereby accelerating the action of the switch 420 and shortening the action time of the switch 420. Among them, the conduction time of the second switch tube Q2 is related to the time constant (C1*(R3+R2)), wherein C1 represents the capacitance of the first capacitor C1, R3 represents the resistance of the third resistor R3, and R2 represents the resistance of the second resistor R2. By changing the selection of each component, the conduction time of the second switch tube Q2 can be changed. After the first capacitor C1 is fully charged, the voltages across the first capacitor C1 are equal again without a voltage difference, the second switch tube Q2 is turned off, and the auxiliary power supply 430 supplies power to the coil L through the first resistor R1 to the ground terminal G. At this time, the current in the circuit is small, thereby reducing the loss of the coil L.

[0074] In the power conversion device 400 provided in the embodiment of the present application, the controller 440 controls the first switch tube Q1 to be turned on, so that the auxiliary power supply 430 charges the first capacitor C1, and adjusts the voltage of the controlled end of the second switch tube Q2 to turn on the second switch tube Q2. The auxiliary power supply 430 provides a larger voltage to the coil L through the second switch tube Q2, thereby speeding up the action of the switch 420 and shortening the action time of the switch 420. And the conduction time of the second switch tube Q2 is related to the resistance value of the second resistor R2, the resistance value of the third resistor R3 and the capacitance value of the first capacitor C1. By adjusting the resistance value of the second resistor R2, the resistance value of the third resistor R3 and the capacitance value of the first capacitor C1, the conduction time of the second switch tube Q2 can be adjusted to be greater than or equal to the action time of the switch 420, and less than or equal to the preset threshold value, so as to ensure that the action of the switch 420 is accelerated during the action of the switch 420. After the action of the switch 420, the second switch tube Q2 can be turned off, and the auxiliary power supply 430 supplies power to the coil L through the first resistor R1. At this time, the current in the circuit is small, which can reduce the loss of the coil L.

[0075] In a possible embodiment, the circuit topology of the power conversion device 400 is as follows: Figure 3 (a) or Figure 4Taking the circuit topology of the power conversion device 400 shown in FIG. 4 as an example, the power conversion device 400 further includes a first diode D1, such as Figure 3 As shown in (a), the anode of the first diode D1 is connected to the controlled end of the second switch tube Q2, and the cathode of the first diode D1 is connected to the source or emitter of the second switch tube Q2, or, as Figure 4 As shown, the cathode of the first diode D1 is connected to the controlled end of the second switch tube Q2, and the anode of the first diode D1 is connected to the source or emitter of the second switch tube Q2.

[0076] Reference Figure 3 (a) or Figure 4 , when the controller 440 controls the first switch tube Q1 to turn on, the first capacitor C1 is charged, and the switch 420 is actuated, the controller 440 controls the first switch tube Q1 to turn off: the first capacitor C1 is discharged through the first diode D1 and the third resistor R3, without passing through the second resistor R2, so that when the first capacitor C1 is discharged, a higher voltage is not applied between the controlled end of the second switch tube Q2 and the source or emitter of the second switch tube Q2, which can avoid damage to the second switch tube Q2 and improve the reliability of the power conversion device 400. At the same time, the RCD buffer circuit composed of the first capacitor C1, the third resistor R3, the first diode D1 and the first resistor R1 can absorb the peak voltage generated by the back electromotive force in the coil L, can protect the first switch tube Q1 and the second switch tube Q2, and can improve the reliability of the power conversion device 400.

[0077] The power conversion device 400 provided in the embodiment of the present application is provided with a first diode D1. When the controller 440 controls the first switch tube Q1 to be turned on, the first capacitor C1 is charged, and the switch 420 is actuated, the controller 440 controls the first switch tube Q1 to be turned off. The first capacitor C1 is discharged through the first diode D1 and the third resistor R3 without passing through the second resistor R2, thereby preventing a higher voltage from being applied between the controlled end of the second switch tube Q2 and the source or emitter of the second switch tube Q2 when the first capacitor C1 is discharged, thereby preventing the second switch tube Q2 from being damaged, and improving the reliability of the power conversion device 400. At the same time, the RCD buffer circuit composed of the first capacitor C1, the third resistor R3, the first diode D1 and the first resistor R1 can absorb the peak voltage generated by the back electromotive force in the coil L, protect the first switch tube Q1 and the second switch tube Q2, and improve the reliability of the power conversion device 400.

[0078] In a possible embodiment, Figure 3 (a) or Figure 4As shown, the power conversion device 400 may further include a voltage-stabilizing diode ZD and a second diode D2. By providing the voltage-stabilizing diode ZD and the second diode D2, when the controller 440 controls the first switch tube Q1 to be turned on and the switch 420 is actuated, and the controller 440 controls the first switch tube Q1 to be turned off, the voltage-stabilizing diode ZD is used to absorb the peak voltage generated by the back electromotive force in the coil L, which can protect the first switch tube Q1 and the second switch tube Q2, and improve the reliability of the power conversion device 400. The second diode D2 is used to ensure the unidirectional flow of current, prevent voltage reverse impact, and avoid short circuit of the auxiliary power supply 430, and improve the reliability of the power conversion device 400.

[0079] In a possible embodiment, Figure 3 As shown in (a), the cathode of the Zener diode ZD is connected to the cathode of the second diode D2, the anode of the Zener diode ZD is connected to one end of the coil L current input, and the anode of the second diode D2 is connected to one end of the coil L current output. Or, Figure 4 As shown, the anode of the Zener diode ZD is connected to the anode of the second diode D2, the cathode of the second diode D2 is connected to one end of the coil L current input, and the cathode of the Zener diode ZD is connected to one end of the coil L current output, which is not limited in this embodiment of the present application.

[0080] The power conversion device 400 provided in the embodiment of the present application is provided with a Zener diode ZD and a second diode D2. When the controller 440 controls the first switch tube Q1 to be turned on and the switch 420 is actuated, and the controller 440 controls the first switch tube Q1 to be turned off, the Zener diode ZD is used to absorb the peak voltage generated by the back electromotive force in the coil L, thereby protecting the first switch tube Q1 and the second switch tube Q2, thereby improving the reliability of the power conversion device 400. The second diode D2 is used to ensure the unidirectional flow of current, prevent reverse voltage shock, and avoid short circuit of the auxiliary power supply 430, thereby improving the reliability of the power conversion device 400.

[0081] In a possible embodiment, the circuit topology of the power conversion device 400 is as follows: Figure 4 Taking the circuit topology of the power conversion device 400 shown in FIG. 4 as an example, the above-mentioned voltage regulator diode ZD can be replaced by a capacitor and a resistor connected in parallel. Figure 4 ,like Figure 5 As shown, the power conversion device 400 may further include a second capacitor C2, a fourth resistor R4 and a second diode D2, and the second capacitor C2 and the fourth resistor R4 are connected in parallel. Figure 5When the controller 440 controls the first switch tube Q1 to turn on and the switch 420 is actuated, and the controller 440 controls the first switch tube Q1 to turn off, the RCD buffer circuit composed of the second capacitor C2, the fourth resistor R4 and the second diode D2 can absorb the peak voltage generated by the back electromotive force in the coil L, protect the first switch tube Q1 and the second switch tube Q2, and improve the reliability of the power conversion device 400. At the same time, the second diode D2 is used to ensure the unidirectional flow of current, prevent voltage reverse impact, and avoid short circuit of the auxiliary power supply 430, which can improve the reliability of the power conversion device 400.

[0082] Reference Figure 5 , one end of the second capacitor C2 and the fourth resistor R4 connected in parallel is connected to the anode of the second diode D2, the cathode of the second diode D2 is connected to one end of the coil L current input, and the other end of the second capacitor C2 and the fourth resistor R4 connected in parallel is connected to one end of the coil L current output. Alternatively, one end of the second capacitor C2 and the fourth resistor R4 connected in parallel is connected to the cathode of the second diode D2, the other end of the second capacitor C2 and the fourth resistor R4 connected in parallel is connected to one end of the coil L current input, and the anode of the second diode D2 is connected to one end of the coil L current output, which is not limited in the embodiment of the present application.

[0083] The power conversion device 400 provided in the embodiment of the present application is provided with a second capacitor C2, a fourth resistor R4 and a second diode D2. When the controller 440 controls the first switch tube Q1 to be turned on and the switch 420 is actuated, and the controller 440 controls the first switch tube Q1 to be turned off, the RCD buffer circuit composed of the second capacitor C2, the fourth resistor R4 and the second diode D2 can absorb the peak voltage generated by the back electromotive force in the coil L, protect the first switch tube Q1 and the second switch tube Q2, and improve the reliability of the power conversion device 400. At the same time, the second diode D2 is used to ensure the unidirectional flow of current, prevent voltage reverse shock, and avoid short circuit of the auxiliary power supply 430, which can improve the reliability of the power conversion device 400.

[0084] like Figure 5As shown, the embodiment of the present application further provides an uninterruptible power supply 500, which includes a main circuit 510, a bypass circuit 520 and a load end. The main circuit 510 is used to connect to the first input power supply 210, and the bypass circuit 520 is used to connect to the second input power supply 220. The main circuit 510 and the bypass circuit 520 are both used to supply power to the load end, and the load end is used to connect to the load 300 to supply power to the load 300. A rectifier circuit 511 and a power conversion device 400 are provided on the main circuit 510. The input end of the rectifier circuit 511 is used to connect to the first input power supply 210, and the output end of the rectifier circuit 511 is connected to the positive DC bus BUS+ and the negative DC bus BUS-. The input end of the power conversion device 400 is connected to the positive DC bus BUS+ and the negative DC bus BUS-. The output end of the power conversion device 400 is connected to the load end. The circuit topology of the power conversion device 400 can be Figures 2 to 5 The circuit topology of any power conversion device 400 shown in the figure is not limited in the embodiments of the present application.

[0085] Based on this, Figure 6 As shown, the embodiment of the present application also provides a photovoltaic inverter 600, which includes a direct current direct current (DCDC) conversion circuit 610 and a power conversion device 400 connected to the DCDC conversion circuit 610. The power conversion device 400 is used to convert the direct current output by the DCDC conversion circuit 610 into alternating current. The circuit topology of the power conversion device 400 is as follows: Figures 2 to 5 The circuit topology of any power conversion device 400 shown in the figure is not limited in the embodiments of the present application.

[0086] In one possible embodiment, referring to Figures 2 to 5 The solution of accelerating the action of the switch 420 by using the first switch tube Q1, the second switch tube Q2 and the first resistor R1 in the embodiment of the present application can also be applied to other devices such as primary power supplies or charging piles that need to shorten the switching action time, and the embodiment of the present application is not limited to this.

[0087] The above detailed description of the power conversion device 400 and the analysis of the beneficial effects can be correspondingly referred to the uninterruptible power supply 500 and the photovoltaic inverter 600, and the embodiments of the present application will not be repeated here.

[0088] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A power conversion device, characterized in that: The power conversion device includes an inverter circuit, a switch, a first resistor, a first switch tube, a second switch tube and an auxiliary power supply; The positive input terminal of the inverter circuit is connected to the positive DC bus, and the negative input terminal of the inverter circuit is connected to the negative DC bus; The switch comprises a coil, a moving contact and a stationary contact, wherein the moving contact and the stationary contact are respectively connected to the output end of the inverter circuit and the output end of the power conversion device, and the coil is used to drive the moving contact and the stationary contact to move mutually; The first end of the first switch tube is connected to the ground end, and the coil and the first resistor are connected in series between the output end of the auxiliary power supply and the second end of the first switch tube; The second switch tube is connected in parallel with the first resistor.

2. The power conversion device according to claim 1, characterized in that: The power conversion device also includes a controller; The controller is used to control the first switch tube and the second switch tube to be turned on at the same time, and control the conduction time of the second switch tube to be greater than or equal to the action time of the switch.

3. The power conversion device according to claim 2, characterized in that: The controller controls the conduction time of the second switch tube to be greater than or equal to the action time of the switch and less than or equal to a preset threshold.

4. The power conversion device according to any one of claims 1 to 3, characterized in that: The power conversion device further includes a second resistor arranged between the controlled end of the second switch tube and the source or emitter of the second switch tube, and a third resistor and a first capacitor connected in series; The controller is used to control the first switch tube to be turned on, so that the auxiliary power supply charges the first capacitor, so that the second switch tube is turned on, and the turn-on time of the second switch tube is related to the resistance value of the second resistor, the resistance value of the third resistor and the capacitance value of the first capacitor.

5. The power conversion device according to claim 4, characterized in that: The second switch tube is a PMOS or PNP type transistor; One end of the first resistor is connected to the output end of the auxiliary power supply, one end of the coil is connected to the second end of the first switch tube, and the other end of the coil is connected to the other end of the first resistor; The third resistor and the first capacitor are connected in series between the controlled end of the second switch tube and the second end of the first switch tube.

6. The power conversion device according to claim 5, characterized in that: The power conversion device further includes a first diode, an anode of the first diode is connected to the controlled end of the second switch tube, and a cathode of the first diode is connected to the source or emitter of the second switch tube.

7. The power conversion device according to claim 4, characterized in that: The second switch tube is an NMOS or NPN type transistor; One end of the coil is connected to the output end of the auxiliary power supply, one end of the first resistor is connected to the second end of the first switch tube, and the other end of the coil is connected to the other end of the first resistor; The third resistor and the first capacitor are connected in series between the output end of the auxiliary power supply and the controlled end of the second switch tube.

8. The power conversion device according to claim 7, characterized in that: The power conversion device also includes a first diode, a cathode of the first diode is connected to the controlled end of the second switch tube, and an anode of the first diode is connected to the source or emitter of the second switch tube.

9. The power conversion device according to any one of claims 1 to 8, characterized in that: The power conversion device also includes a voltage regulator diode and a second diode; The cathode of the voltage stabilizing diode is connected to the cathode of the second diode, the anode of the voltage stabilizing diode is connected to one end of the coil current input, and the anode of the second diode is connected to one end of the coil current output; or, The anode of the voltage-stabilizing diode is connected to the anode of the second diode, the cathode of the second diode is connected to one end of the coil current input, and the cathode of the voltage-stabilizing diode is connected to one end of the coil current output.

10. The power conversion device according to any one of claims 1 to 8, characterized in that: The power conversion device further includes a second capacitor, a fourth resistor and a second diode, wherein the second capacitor and the fourth resistor are connected in parallel; One end of the second capacitor and the fourth resistor connected in parallel is connected to the anode of the second diode, the cathode of the second diode is connected to one end of the coil current input, and the other end of the second capacitor and the fourth resistor connected in parallel is connected to one end of the coil current output; or, One end of the second capacitor and the fourth resistor connected in parallel is connected to the cathode of the second diode, the other end of the second capacitor and the fourth resistor connected in parallel is connected to one end of the coil current input, and the anode of the second diode is connected to one end of the coil current output.

11. An uninterruptible power supply, characterized in that: The uninterruptible power supply comprises a main circuit, a bypass circuit and a load end, and both the main circuit and the bypass circuit are used to supply power to the load end; A rectifier circuit and a power conversion device are provided on the main line, the input end of the rectifier circuit is connected to the input end of the uninterruptible power supply, the output end of the rectifier circuit is connected to the input end of the power conversion device, the output end of the power conversion device is connected to the load end, the load end is used to connect a load, and the power conversion device is a power conversion device as described in any one of claims 1-10.

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