WO2022011596A1

WO2022011596A1 - Isolation circuit, and isolation method

Info

Publication number: WO2022011596A1
Application number: PCT/CN2020/102111
Authority: WO
Inventors: 李祥; 吴壬华
Original assignee: 深圳欣锐科技股份有限公司
Priority date: 2020-07-15
Filing date: 2020-07-15
Publication date: 2022-01-20
Also published as: CN112956098B; CN112956098A

Abstract

An isolation circuit comprises a voltage sampling circuit (10), an input power supply (11), a control circuit (12), a relay circuit (13), an internal circuit (14), and a control center (17). An output terminal of the input power supply (11) is connected to an input terminal of the voltage sampling circuit (10) and a first terminal of the relay circuit (13). A second terminal of the relay circuit (13) is connected to an output terminal of the control circuit (12). A third terminal of the relay circuit (13) is connected to the internal circuit (14). A first terminal of the control center (17) is connected to the input terminal of the voltage sampling circuit (10). A second terminal of the control center (17) is connected to an input terminal of the control circuit (12). The voltage sampling circuit (10) transmits a sampled output voltage of the input power supply (11) to the control center (17). If the control center (17) determines that the output voltage is not within a preset range, the control center (17) sends a control instruction to the control circuit (12), wherein the control instruction is used to instruct the control circuit (12) to control the relay circuit (13) to be off, such that the input power supply (11) is isolated from the internal circuit (14). In this way, the invention provides protection to elements within a switching power supply while ensuring the quality of a power grid.

Description

Isolation circuit, isolation method

technical field

The present application relates to the field of electrical technology, and in particular, to an isolation circuit and an isolation method.

Background technique

A switching power supply is a power conversion device and a type of power supply. Compared with traditional power supplies, switching power supplies have the advantages of small size and high conversion efficiency, so they are widely used in power supply occasions for various equipment.

In the internal structure of the switching power supply, a large-capacity capacitor is required to support the voltage of the input DC bus. Since the capacitor has the characteristic that the voltage cannot be suddenly changed, the capacitor is equivalent to a short circuit at the moment when the power is turned on, and the inrush current in the circuit will be very large. , not only will affect the quality of the power grid, but also may cause damage to internal components. In order to improve this phenomenon, a precharge circuit is usually added to limit the charging current of the capacitor through a current limiting resistor. There are one or more relays connected to the precharge resistors in the common precharge circuits on the market. When the input power supply is overvoltage, the input power supply and the internal circuit will still form a path through the precharge resistor, which may cause the internal components of the switching power supply. The overvoltage damage of the device will also cause surge impact on the power grid and affect the quality of the power grid.

Application content

Based on this, the present application provides an isolation circuit and an isolation method, the isolation circuit can isolate the input power supply from the components inside the switching power supply, which can not only realize the function of the precharge circuit, but also solve the problem of the output of the input voltage source. When the voltage is overvoltage, it will cause problems such as overvoltage damage to the internal components.

In a first aspect, an embodiment of the present application provides an isolation circuit, including a voltage sampling circuit, an input power supply, a control circuit, a relay circuit, an internal circuit, and a control center;

The output end of the input power supply is connected to the input end of the voltage sampling circuit and the first end of the relay circuit, the second end of the relay circuit is connected to the output end of the control circuit, and the relay circuit is connected to the output end of the control circuit. The third end is connected to the internal circuit, the first end of the control center is connected to the input end of the voltage sampling circuit, and the second end of the control center is connected to the input end of the control circuit;

The voltage sampling circuit transmits the sampled output voltage of the input power supply to the control center, and when the control center determines that the output voltage is not within a preset range, sends a control instruction to the control circuit, The control instruction is used to instruct the control circuit to control the relay circuit to turn off, so that the input power supply is isolated from the internal circuit.

In a possible implementation manner, the isolation circuit further includes an auxiliary power supply and a pre-charging resistor circuit;

The output end of the auxiliary power supply is connected to the fourth end of the relay circuit, the first end of the precharge resistance circuit is connected to the output end of the input power supply, and the second end of the precharge resistance circuit is connected to the The fifth terminal of the relay circuit is connected, and the third terminal of the pre-charging resistor circuit is connected to the sixth terminal of the relay circuit.

In a possible implementation manner, when the input power supply is three-phase input power, the control circuit includes a first control circuit and a second control circuit, and the relay circuit includes a first relay, a second relay, and a second control circuit. three relays;

The output end of the first control circuit is respectively connected to the first end of the first relay and the first end of the second relay, and the input end of the first control circuit is connected to the first output of the control center terminal, the output terminal of the second control circuit is connected to the first terminal of the third relay, the input terminal of the second control circuit is connected to the second output terminal of the control center; the first terminal of the voltage sampling circuit An input terminal is respectively connected to the first output terminal of the input power supply and the second terminal of the first relay, and the second input terminal of the voltage sampling circuit is respectively connected to the second output terminal of the input power supply and the second terminal of the first relay. The second end of the second relay is connected, the third input end of the voltage sampling circuit is respectively connected to the third output end of the input power supply and the second end of the third relay, and the output end of the voltage sampling circuit connected to the control center; the third end of the first relay is connected to the first input end of the internal circuit, and the third end of the second relay is connected to the second input end of the internal circuit; the The third terminal of the third relay is connected to the third input terminal of the internal circuit.

In a possible implementation manner, the first end of the precharging resistor circuit is respectively connected with the first output end of the input power supply, the second end of the first relay and the first input of the voltage sampling circuit The second end of the pre-charging resistance circuit is connected to the third end of the first relay and the first input end of the internal circuit respectively; the output end of the auxiliary power supply is respectively connected to the first relay The fourth end of the second relay and the fourth end of the third relay are connected.

In a possible implementation manner, the first relay includes: a first diode, a first switch, and a first coil;

The anode of the first diode is respectively connected to the first end of the first coil and the output end of the first control circuit, and the cathode of the first diode is respectively connected to the first end of the first coil. The two terminals are connected to the output terminal of the auxiliary power supply.

In a possible implementation manner, the second relay includes: a second diode, a second switch, and a second coil;

The anode of the second diode is respectively connected to the first end of the second coil and the output end of the first control circuit, and the cathode of the second diode is respectively connected to the first end of the second coil. The two terminals are connected to the output terminal of the auxiliary power supply.

In a possible implementation manner, the third relay includes: a third diode, a third switch, and a third coil;

The anode of the third diode is respectively connected to the first end of the third coil and the output end of the second control circuit, and the cathode of the third diode is respectively connected to the first end of the third coil. The two terminals are connected to the output terminal of the auxiliary power supply.

In a possible implementation manner, the first control circuit includes: a first MOS transistor;

The drain of the first MOS transistor is respectively connected to the anode of the first diode, the first end of the first coil, the anode of the second diode, and the first end of the second coil. connected, the source of the first MOS transistor is grounded, and the gate of the first MOS transistor receives the input signal;

In a possible implementation manner, the second control circuit includes: a second MOS transistor;

The drain of the second MOS transistor is respectively connected to the anode of the third diode and the first end of the third coil, the source of the second MOS transistor is grounded, and the source of the second MOS transistor is connected to the ground. The gate receives the input signal.

In a second aspect, the present application further provides an isolation method, which is applied to the isolation circuit described in the first aspect, where the isolation circuit includes an input power supply, a relay circuit, and an internal circuit, the relay circuit and the internal circuit connection, the method includes:

sampling the output voltage of the input power supply;

judging whether the output voltage of the input power supply is within a preset range;

When it is determined that the output voltage of the input power supply is not within the preset range, the relay circuit is controlled to be turned off, so as to disconnect the input power supply and the internal circuit.

In a possible implementation manner, after the controlling the relay circuit to turn off, the method further includes:

When it is determined that the output voltage of the input power supply is within the preset range, the relay circuit is controlled to pull in, so as to connect the input power supply and the internal circuit.

In a third aspect, the present application further provides a switching power supply, the switching power supply comprising an internal circuit and the isolation circuit according to any possible implementation manner of the first aspect, the isolation circuit being provided in the switching power supply.

The circuit provided by the embodiment of the present application can ensure that the internal circuit of the input power supply does not form a path by controlling the disconnection of the relay when it is detected that the voltage is too high, so that the internal components of the switching power supply can be effectively protected while the precharge function is realized. Without being damaged, it can also make the power grid not impacted by surges and ensure the quality of the power grid.

Description of drawings

The accompanying drawings required to be used in the description of the embodiments or the prior art will be briefly introduced below.

FIG. 1 is a schematic structural diagram of an isolation circuit provided by an embodiment of the present application;

FIG. 2 is a schematic structural diagram of another isolation circuit provided by an embodiment of the present application;

3 is a schematic structural diagram of another isolation circuit provided by an embodiment of the present application;

4 is a schematic structural diagram of a switching power supply provided by an embodiment of the present application;

FIG. 5 is a schematic flowchart of an isolation method provided by an embodiment of the present application.

detailed description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present application.

The terms "first", "second", "third" and "fourth" in the description and claims of the present application and the above drawings are used to distinguish different objects, rather than to describe a specific order. Furthermore, the terms "comprising" and "having", and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units is not limited to the listed steps or units, but optionally also includes unlisted steps or units, or optionally also includes For other steps or units inherent to these processes, methods, products or devices.

Reference herein to an "embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the present application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor a separate or alternative embodiment that is mutually exclusive of other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

Please refer to FIG. 1 , which is a schematic structural diagram of an isolation circuit provided by the present application. As shown in FIG. 1 , the above isolation circuit includes a voltage sampling circuit 10 , an input power supply 11 , a control circuit 12 , a relay circuit 13 , an internal circuit 14 , and a control center 17 ;

The output end of the input power supply 11 is connected to the input end of the voltage sampling circuit 10 and the first end of the relay circuit 13 , the second end of the relay circuit 13 is connected to the output end of the control circuit 12 , and the relay circuit 13 is connected to the output end of the control circuit 12 . The third end is connected to the internal circuit 14, the first end of the control center 17 is connected to the input end of the voltage sampling circuit 10, and the second end of the control center 17 is connected to the input end of the control circuit 12;

The above-mentioned voltage sampling circuit 10 transmits the sampled output voltage of the above-mentioned input power supply 11 to the above-mentioned control center 17. When the above-mentioned control center 17 judges that the above-mentioned output voltage is not within the preset range, it sends a control command to the above-mentioned control circuit 12, and the above-mentioned The control instruction is used to instruct the above-mentioned control circuit 12 to control the above-mentioned relay circuit 13 to turn off, so that the above-mentioned input power supply 11 is isolated from the above-mentioned internal circuit 14 .

Wherein, the above-mentioned isolation circuit further includes an auxiliary power supply 15 and a pre-charging resistance circuit 16;

The output end of the auxiliary power supply 15 is connected to the fourth end of the relay circuit 13; the first end of the precharge resistance circuit 16 is connected to the output end of the input power supply 11, and the second end of the precharge resistance circuit 16 is connected to the above The fifth terminal of the relay circuit 13 is connected, and the third terminal of the pre-charging resistor circuit 15 is connected to the sixth terminal of the relay circuit 13 .

The working principle of the isolation circuit provided in the embodiment of the present application is as follows: taking the input power supply as an example of three-phase AC input power, the voltage sampling circuit 10 collects the output voltage of the input power supply, and transmits the collected output voltage to the control center 17 (microcontroller unit , MCU), the control center 17 judges whether the output voltage is within the preset voltage threshold range, and if it is judged that the output voltage is not (exceeds) the preset voltage threshold range, then the control center 17 sends a control command to the control circuit 12, The instruction is used to instruct the control circuit 12 to control the relays in the relay circuit 13 to turn off, so as to isolate the input power supply 11 from the internal circuit 14 .

Optionally, when the control center 17 determines that the output voltage is within the preset voltage threshold range, it sends a pull-in instruction to the control circuit 12, and the instruction is used to instruct the control circuit 12 to control the relay in the relay circuit 13 to pull-in, One of the relays in the relay circuit can be pulled in first, so that the circuit forms a loop to charge the capacitor in the internal circuit 14. After the charging is completed, when the internal circuit 14 detects that the voltage across the capacitor rises to a preset value, the other circuits are closed. Two relays, thereby connecting the input power supply 11 to the internal circuit 14 .

Please refer to FIG. 2 , which is a schematic structural diagram of another isolation circuit provided by an embodiment of the present application. As shown in FIG. 2 , the above-mentioned isolation circuit is an example of three-phase input power for explanation. The isolation circuit shown in FIG. 2 is obtained by refining the isolation circuit shown in FIG. 1. Compared with the isolation circuit shown in FIG. 1, the three-phase input power in the isolation circuit shown in FIG. 2 can be The three-phase AC input can also be a three-phase DC input. When the input power is three-phase input power, the above-mentioned relay circuit can be configured with three relays, namely a first relay, a second relay and a third relay. Wherein, the above three relays may be controlled by two control circuits, or the three relays may be controlled by three control circuits respectively. This application takes two control circuits as an example for explanation. When there are two control circuits, the first control circuit may control the first relay and the second relay, and the second control circuit may control the third relay. It should be noted that when the input of the isolation circuit provided in this application is a three-phase AC input or a three-phase DC input, the relay circuit includes three relays. When the input of the isolation circuit is a single-phase AC input or a single-phase DC input At this time, the relay circuit may include one relay, that is, the number of relays is related to the type of the input power supply, and the application does not limit the type of the input power supply.

In the circuit structure of the embodiment of the present application, the output end of the first control circuit 201 is connected to the first end of the first relay 204 and the first end of the second relay 205 respectively, and the input end of the first control circuit 201 is connected to the control The first output end of the center 211, the output end of the second control circuit 202 is connected to the first end of the third relay 206, the input end of the second control circuit 202 is connected to the second output end of the control center 211; the above The first input terminal of the voltage sampling circuit 203 is respectively connected to the first output terminal of the above-mentioned input power supply 209 and the second terminal of the above-mentioned first relay 204, and the second input terminal of the above-mentioned voltage sampling circuit 203 is respectively connected to the above-mentioned input power supply 209. The two output terminals are connected to the second terminal of the second relay 205, the third input terminal of the voltage sampling circuit 203 is connected to the third output terminal of the input power supply 209 and the second terminal of the third relay 206, respectively, and the voltage The output end of the sampling circuit 203 is connected to the above-mentioned control center 211 .

Both the first control circuit 201 and the second control circuit 202 send a shutdown signal to the relay to ensure that the input power supply 209 can be isolated from the internal circuit 210 in case of overvoltage. The voltage sampling circuit 203 collects the output voltage signal of the input power supply 209 to determine whether the output voltage is within the allowable range. The allowable range here refers to the normal operating voltage range of the components in the internal circuit 210 . The voltage sampling circuit 203 transmits the sampled signal to the control center 211, and the control center 211 judges whether the sampled output voltage is within the allowable range. When judging that the output voltage is within the allowable range, the control center 211 issues a closing command. The control center 211 sends a turn-off command or a turn-on command to the first control circuit 201 and the second control circuit 202, so that the first control circuit 201 and the second control circuit 202 respectively control the controlled relays.

The third terminal of the first relay 204 is connected to the first input terminal of the internal circuit 210 , the third terminal of the second relay 205 is connected to the second input terminal of the internal circuit 210 , and the third terminal of the third relay 206 is connected. The terminal is connected to the third input terminal of the above-mentioned internal circuit 210 . Among them, the relay here takes an electromagnetic relay as an example, which can be an electromagnetic relay, a solid-state relay, or a reed relay, which is not limited here.

The isolation circuit further includes an auxiliary power supply 208 and a pre-charging resistor circuit 207. The output terminal of the auxiliary power supply 208 is connected to the fourth terminal of the first relay 204, the fourth terminal of the second relay 205, and the third relay 206, respectively. the fourth terminal connection. The first terminal of the pre-charging resistor circuit 207 is respectively connected to the first output terminal of the above-mentioned input power supply 209 , the second terminal of the above-mentioned first relay 204 and the first input terminal of the above-mentioned voltage sampling circuit 203 . The second terminals are respectively connected to the third terminal of the first relay 204 and the first input terminal of the internal circuit 210 . The auxiliary power supply 208 is used to supply power to the three relays respectively, and the pre-charging resistor circuit 207 is used to limit the inrush current when the input power supply 209 is powered on.

In a possible implementation manner, when the input power supply 209 is abnormal, the voltage sampling circuit 203 collects the output voltage signal and transmits it to the control center 211, and the control center 211 judges whether the currently collected output voltage signal is within the threshold range, When it is determined that the output voltage is not within the threshold range, an instruction to turn off the first relay 204 and the second relay 205 is sent to the first control circuit 201, and an instruction to turn on the third relay 206 is sent to the second control circuit 202, so that The internal circuit 210 is isolated from the input power supply 209 to protect the components in the internal circuit 210 . The voltage sampling circuit 203 may transmit sampling signals to the control center 211 through a software program, and the control center 211 may also send instructions to the second control circuit 202 through a software program, or may send instructions in other ways, which are not limited here. The interval of the threshold value range can also be determined according to the input power supply 209 and the internal circuit 210. For example, in the case of 220 volts (V) commercial power, the threshold value interval can be 85-265 volts (V), and the threshold value interval is not limited. At this time, the input power supply 209 and the internal circuit 210 form a loop through the third relay 206 and the pre-charging resistance circuit 207, and the capacitor in the internal circuit 210 is charged through the pre-charging resistance circuit 207, wherein the internal circuit 210 can include the DC bus of the switching power supply. capacitance. In addition, the circuit in the internal circuit 210 can measure the voltage of the DC bus capacitor, and the internal circuit 210 can also transmit the measured voltage of the DC bus capacitor to the control center 211, until the control center 211 determines that the measured voltage reaches the predetermined level. After setting the value, the first control circuit 201 sends the command to pull in the first relay 204 and the second relay 205, and the first control circuit 201 sends the pull-in command to the first relay 204 and the second relay 205, At this time, the pre-charging process ends, and the input power supply 209 and the internal circuit 210 are turned on.

Further, when the output voltage of the input power supply is too high, the overvoltage protection can be triggered, and the operation can be stopped by means of a software program, and at this time, the first relay 204, the second relay 205 and the third relay 206 do not receive When the pull-in command is reached, it will not form a path with the internal circuit 210 , which effectively isolates the input power supply 209 from the components in the internal circuit 210 .

Please refer to FIG. 3 . FIG. 3 is a schematic structural diagram of another isolation circuit provided by an embodiment of the present application, as shown in FIG. 3 . Among them, the isolation circuit shown in Figure 3 is obtained by refining the isolation circuit shown in Figure 2. Compared with the isolation circuit shown in Figure 2, the relay in Figure 3 is an electromagnetic relay, which uses the electromagnetic effect to The mechanical contact is controlled to achieve the purpose of on and off, and the iron core coil is energized so that the coil current generates a magnetic field, and the magnetic field attracts the armature to act on and off the contacts to achieve the purpose of pulling in and turning off. The first relay sub-circuit 204 includes: a first diode D1, a first switch S1, and a first coil L1; the anode of the first diode D1 is connected to the first end of the first coil L1 and the first end of the first coil L1 and the first coil L1 respectively. An output end of the control circuit 201 is connected, and the cathode of the first diode D1 is connected to the second end of the first coil L1 and the output end of the auxiliary power supply 208 respectively; the second relay sub-circuit 205 includes: a second two The pole tube D2, the second switch S2, the second coil L2; the anode of the second diode D2 is respectively connected to the first end of the second coil L2 and the output end of the first control circuit 201, the second two The cathode of the pole tube D2 is respectively connected with the second end of the second coil L2 and the output end of the auxiliary power supply 208; the third relay 206 includes: a third diode D3, a third switch S3, and a third coil L3; the above The anode of the third diode D3 is connected to the first end of the third coil L3 and the output end of the second control circuit 202, respectively, and the cathode of the third diode D3 is connected to the second end of the third coil L3, respectively. The terminal is connected to the output terminal of the above-mentioned auxiliary power supply 208 .

Wherein, there are also two control circuits in the isolation circuit, and these two control circuits are respectively used to control the pull-in and turn-off of the three relays. Specifically, the first control circuit 201 includes: a first MOS transistor Q1; the above-mentioned The drain of the first MOS transistor Q1 is connected to the anode of the first diode D1, the first end of the first coil L1, the anode of the second diode D2, and the first end of the second coil L2, respectively. , the source of the first MOS transistor Q1 is grounded, and the gate of the first MOS transistor Q1 receives an input signal; the second control circuit 202 includes: a second MOS transistor Q2; the drain of the second MOS transistor Q2 is respectively connected to The anode of the third diode D3 is connected to the first end of the third coil L3, the source of the second MOS transistor Q2 is grounded, and the gate of the second MOS transistor Q2 receives the input signal.

The first MOS transistor Q1 and the second MOS transistor Q2 may be N-type metal-oxide-semiconductor (N-Metal-Oxide-Semiconductor, NMOS), or may be P-type metal-oxide-semiconductor (positive channel Metal) Oxide Semiconductor, PMOS), used as MOS in the control circuit. The first diode D1, the second diode D2, and the third diode D3 are used to absorb the reverse voltage when the relay is turned off.

Specifically, when an abnormality occurs in the input power supply 209, the voltage sampling circuit 203 collects the output voltage signal and sends it to the control center, and the control center judges whether the currently collected output voltage signal is within the threshold range, and when it judges that the output voltage is not within the threshold range , the command to turn off the first relay 204 and the second relay 205 is sent to the first control circuit 201, and the command to turn on the third relay 206 is sent to the second control circuit 202. Second, the control circuit 202 sends the instruction, and may also send the instruction in other ways, which is not limited here. When the voltage sampling circuit, the control center and the control circuit transmit data and instructions through software programs, there may be no direct connection relationship in the circuit connection. It should be noted that the control center can receive the output voltage transmitted by the voltage sampling circuit, and can also send instructions to the first control circuit and the second control circuit, and can also be used for other control, which is not limited here.

At this time, the input power supply 209 and the internal circuit 210 form a loop through the third relay 206 that closes the third switch S3 and the pre-charging resistor circuit R1, and the capacitor in the internal circuit 210 is charged through the pre-charging resistor circuit R1, wherein the internal circuit 210 The DC bus capacitor of the switching power supply can be included. And in the internal circuit 210, the voltage of the DC bus capacitor can be measured, and the internal circuit 210 can also transmit the measured voltage of the DC bus capacitor to the control center. After the control center determines that the measured voltage reaches the preset value, Then the control center sends an instruction to pull in the first switch S1 of the first relay 204 and the second switch S2 of the second relay 205 to the first control circuit 201, and the first control circuit 201 sends the command to the first relay 204 and the second switch S2 of the second relay 205. The two relays 205 respectively send commands to pull in the first switch S1 and the second switch S2. At this time, the pre-charging process ends, and the input power supply 209 and the internal circuit 210 are turned on.

Further, when the output voltage of the input power supply 209 is too high, the overvoltage protection can be triggered, and the operation can be stopped by means of a software program or the like, and at this time, the first switch S1 in the first relay 204 and the second relay 205 The second switch S2 and the third switch S3 in the third relay 206 do not receive the pull-in command, so they will not form a path with the internal circuit 210 , effectively isolating the input power 209 from the components in the internal circuit 210 .

Please refer to FIG. 4 , which is a schematic structural diagram of a switching power supply provided by an embodiment of the present application. The switching power supply 400 includes: a memory 401 , a processor 402 coupled with the above-mentioned memory 401 , and an isolation circuit 403 . The memory 401 is used to store instructions, the processor 402 is used to execute the instructions, and the isolation circuit 403 is used to isolate the input power supply from the internal components of the switching power supply.

Optionally, the above-mentioned switching power supply 400 may further include a transceiver 405 , and the transceiver 405 is configured to communicate with other devices under the control of the processor 402 .

The processor 402 may be a central processing unit (CPU), a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), or a field programmable A field programmable gate array (FPGA) or other programmable logic device, transistor logic device, hardware component, or any combination thereof. It may implement or execute various exemplary logical blocks, modules and circuits described in connection with the disclosure of the embodiments of the present application. A processor may also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of a DSP and a microprocessor, and the like. The transceiver 405 may be a communication interface, a transceiver circuit, etc., wherein the communication interface is a general term and may include one or more interfaces.

Optionally, the switching power supply may further include a bus 404 . Wherein, the memory 401, the processor 402, the transceiver 405 and the isolation circuit 403 can be connected to each other through a bus 404; the bus 404 can be a peripheral component interconnect (PCI) bus or an extended industry standard structure (extended industry standard) architecture, EISA) bus, etc. The bus 404 can be divided into an address bus, a data bus, a control bus, and the like. For ease of presentation, only one thick line is used in FIG. 4, but it does not mean that there is only one bus or one type of bus.

In addition to the memory 401, the processor 402, the isolation circuit 403, the transceiver 405, and the above-mentioned bus 404 shown in FIG. 4, the switching power supply in the embodiment of the present application may also include other hardware according to the actual function of the switching power supply. This will not be repeated here. Optionally, the switching power supply can achieve the beneficial effects of the above-mentioned isolation circuit. The structure and function of the isolation circuit 403 may refer to the relevant descriptions in the foregoing embodiments, which will not be repeated here.

Please refer to FIG. 5. FIG. 5 is a schematic flowchart of an isolation method provided by an embodiment of the present application, wherein the method can be applied to the isolation circuit in the above-mentioned FIGS. 1-3, and the above-mentioned isolation circuit includes an input power supply, a relay circuit and Internal circuits, wherein the isolation circuits of FIGS. 1-3 can be used to support and execute the method flow shown in FIG. 5 above. This isolation method includes:

501. Sampling the output voltage of the input power supply.

In a possible implementation manner, sampling data is obtained by sampling the output voltage of the input power supply, and then the sampled output voltage can be compared with a preset voltage threshold range to determine whether the output voltage is within the preset voltage. Within the threshold range; if not, directly connecting the input power supply to the internal circuit will damage the components of the internal circuit, and will also cause a large surge impact to the power grid, affecting the quality of the power grid. Therefore, it is necessary to connect the input power supply to the internal circuit. Isolated; if present, the input power supply can be directly connected to the internal circuit.

Among them, the output voltage of the input power supply can be sampled by the voltage sampling circuit, or the output voltage can be sampled by any circuit with a voltage sampling function in the circuit, and sent to the control center in the circuit for judgment by the control center; or It is the direct sampling and comparison by the control center, which is not limited here.

502. Determine whether the above-mentioned output voltage is within a preset range. When it is determined that the output voltage is not within the preset range, step 503 is performed; when it is determined that the output voltage is within the preset range, step 504 is performed.

In a possible implementation, the voltage sampling circuit samples the output voltage of the input power supply and transmits it to the control center of the circuit. The control center stores a preset voltage threshold range, and the control center can determine whether the output voltage is within the preset voltage threshold. Within the set range, the judgment result is obtained. In the embodiment of the present application, after the control center obtains the judgment result, it sends a control instruction corresponding to the judgment result to the control circuit.

503. The control relay circuit is turned off.

When it is determined in step 502 that the above-mentioned output voltage is not within the preset range, the relay circuit is controlled to be turned off, so as to isolate the input power supply from the internal circuit.

In a possible implementation, when the control center determines that the output voltage is not within the preset range, the control center can directly control the turn-off of the relay, or the control center can send an instruction to the control circuit, and the control circuit controls the relay At the same time, the control circuit can include one control circuit or multiple control circuits, and each control circuit controls the turn-off of different relays respectively, so as to achieve the purpose of isolating the input power supply and the internal circuit.

Optionally, when the control relay is turned off, part of the relay can be closed to form a circuit to charge the DC bus capacitor in the internal circuit, while isolating the input power supply and the internal circuit, and protecting the components of the internal circuit.

Specifically, referring to the isolation circuits in FIGS. 1-3, the output voltage of the input power supply can be collected through the voltage sampling circuit, and the collected output voltage can be transmitted to the control center of the circuit, and the collected output voltage can be judged by the control center. Whether it is within the preset range, when it is judged that it is not within the preset range, send a shutdown control command to the control circuit, the shutdown control command is used to instruct the control circuit to control the relay circuit to turn off, so that the input power supply and the internal circuit isolated. Further, the control center can respectively send control instructions to a plurality of control circuits, and each control circuit respectively controls a plurality of relay circuits to turn off.

504. Control the above-mentioned relay circuit to pull in.

When it is determined based on step 502 that the output voltage is within the preset range, the relay circuit is controlled to pull in, so that the input power supply is connected to the internal circuit.

In a possible implementation manner, by continuously sampling the output voltage of the input power supply, and comparing the sampled output voltage with a preset threshold range, it is determined that when the sampled output voltage is within the voltage threshold range, The connection between the input power supply and the internal circuit will not damage the components of the circuit, then the control relay circuit pulls in, so that the components of the circuit work normally.

Specifically, referring to the isolation circuits in Figures 1 to 3, the output voltage of the input power supply can be collected through the voltage sampling circuit, and the collected output voltage can be transmitted to the control center of the circuit. When the control center determines that the collected output When the voltage is within the preset range, a pull-in control command is sent to the control circuit, and the pull-in control command is used to instruct the control circuit to control the pull-in of the relay circuit, and the components in the circuit work normally.

In the embodiment of the present application, when it is detected that the voltage is not within the preset range, by controlling the turn-off of the relay, the internal components of the circuit can be protected from damage, and the power grid can also be protected from surges, thereby ensuring the quality of the power grid. .

It should be noted that, for the sake of simple description, the foregoing application embodiments are all expressed as a series of action combinations, but those skilled in the art should know that the present application is not limited by the described action sequence. Because in accordance with the present application, certain steps may be performed in other orders or concurrently. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present application.

The units described above as separate components may or may not be physically separated, and components shown as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution in this embodiment.

The above are only specific embodiments of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of various equivalents within the technical scope disclosed in the present application. Modifications or substitutions shall be covered by the protection scope of this application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

An isolation circuit is characterized by comprising a voltage sampling circuit, an input power supply, a control circuit, a relay circuit, an internal circuit and a control center;

The output end of the input power supply is connected to the input end of the voltage sampling circuit and the first end of the relay circuit, the second end of the relay circuit is connected to the output end of the control circuit, and the relay circuit is connected to the output end of the control circuit. The third end is connected to the internal circuit, the first end of the control center is connected to the input end of the voltage sampling circuit, and the second end of the control center is connected to the input end of the control circuit;

The voltage sampling circuit transmits the sampled output voltage of the input power supply to the control center, and when the control center determines that the output voltage is not within a preset range, sends a control instruction to the control circuit, The control instruction is used to instruct the control circuit to control the relay circuit to turn off, so that the input power supply is isolated from the internal circuit.
The isolation circuit according to claim 1, wherein the isolation circuit further comprises an auxiliary power supply and a pre-charging resistor circuit;

The output end of the auxiliary power supply is connected to the fourth end of the relay circuit, the first end of the precharge resistance circuit is connected to the output end of the input power supply, and the second end of the precharge resistance circuit is connected to the The fifth terminal of the relay circuit is connected, and the third terminal of the pre-charging resistor circuit is connected to the sixth terminal of the relay circuit.
The isolation circuit according to claim 2, wherein when the input power is three-phase input power, the control circuit includes a first control circuit and a second control circuit, and the relay circuit includes a first relay, the second relay and the third relay;

The output end of the first control circuit is respectively connected to the first end of the first relay and the first end of the second relay, and the input end of the first control circuit is connected to the first output of the control center terminal, the output terminal of the second control circuit is connected to the first terminal of the third relay, the input terminal of the second control circuit is connected to the second output terminal of the control center; the first terminal of the voltage sampling circuit An input terminal is respectively connected to the first output terminal of the input power supply and the second terminal of the first relay, and the second input terminal of the voltage sampling circuit is respectively connected to the second output terminal of the input power supply and the second terminal of the first relay. The second end of the second relay is connected, the third input end of the voltage sampling circuit is respectively connected to the third output end of the input power supply and the second end of the third relay, and the output end of the voltage sampling circuit connected with the control center; the third end of the first relay is connected with the first input end of the internal circuit; the third end of the second relay is connected with the second input end of the internal circuit; the The third terminal of the third relay is connected to the third input terminal of the internal circuit.
The isolation circuit according to claim 3, wherein the first end of the pre-charging resistor circuit is respectively connected with the first output end of the input power supply, the second end of the first relay and the voltage sampling The first input end of the circuit is connected, the second end of the pre-charging resistor circuit is respectively connected with the third end of the first relay and the first input end of the internal circuit; the output end of the auxiliary power supply is respectively connected with The fourth terminal of the first relay, the fourth terminal of the second relay and the fourth terminal of the third relay are connected.
The isolation circuit according to claim 4, wherein the first relay comprises: a first diode, a first switch, and a first coil;

The anode of the first diode is respectively connected to the first end of the first coil and the output end of the first control circuit, and the cathode of the first diode is respectively connected to the first end of the first coil. The two terminals are connected to the output terminal of the auxiliary power supply.
The isolation circuit according to claim 5, wherein the second relay comprises: a second diode, a second switch, and a second coil;

The anode of the second diode is respectively connected to the first end of the second coil and the output end of the first control circuit, and the cathode of the second diode is respectively connected to the first end of the second coil. The two terminals are connected to the output terminal of the auxiliary power supply.
The isolation circuit according to claim 6, wherein the third relay comprises: a third diode, a third switch, and a third coil;

The anode of the third diode is respectively connected to the first end of the third coil and the output end of the second control circuit, and the cathode of the third diode is respectively connected to the first end of the third coil. The two terminals are connected to the output terminal of the auxiliary power supply.
The isolation circuit according to any one of claims 3-7, wherein the first control circuit comprises: a first MOS transistor; the second control circuit comprises: a second MOS transistor;

The drain of the first MOS transistor is respectively connected with the anode of the first diode, the first end of the first coil, the anode of the second diode and the first end of the second coil connected, the source of the first MOS transistor is grounded, and the gate of the first MOS transistor receives the input signal;

The drain of the second MOS transistor is respectively connected to the anode of the third diode and the first end of the third coil, the source of the second MOS transistor is grounded, and the source of the second MOS transistor is connected to the ground. The gate receives the input signal.
An isolation method, characterized in that, the method is applied to the isolation circuit of any one of claims 1-8, the isolation circuit includes an input power supply, a relay circuit and an internal circuit, the relay circuit and the internal circuit circuit connection, the method comprising:

sampling the output voltage of the input power supply;

judging whether the output voltage of the input power supply is within a preset range;

When it is determined that the output voltage of the input power supply is not within the preset range, the relay circuit is controlled to be turned off, so as to disconnect the input power supply and the internal circuit.
The method according to claim 9, wherein after controlling the relay circuit to turn off, the method further comprises:

When it is determined that the output voltage of the input power supply is within the preset range, the relay circuit is controlled to pull in, so as to connect the input power supply and the internal circuit.