CN108711928B

CN108711928B - Control circuit and control method

Info

Publication number: CN108711928B
Application number: CN201810379519.3A
Authority: CN
Inventors: 唐波
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2018-04-25
Filing date: 2018-04-25
Publication date: 2020-10-23
Anticipated expiration: 2038-04-25
Also published as: CN108711928A

Abstract

The embodiment of the application discloses a control circuit and a control method, relates to the technical field of power supply and distribution, and can enable a UPS power supply system to be switched to an external maintenance bypass for maintenance under the condition that power supply of a tail-end IT load is not interrupted. The control circuit of the embodiment of the application comprises a first control circuit, wherein the first control circuit comprises a first module circuit, a normally closed contact of a second switch, a closing coil of the second switch and an electric closing button of the second switch which are connected in series; the first module circuit comprises a normally open contact of a first switch and a normally closed contact of a first relay which are connected in series, and the normally closed contact of the first switch is connected with the normally open contact of the first switch and the normally closed contact of the first relay in parallel; when the UPS inverter is started, the normally closed contact of the first relay is disconnected. The scheme provided by the embodiment of the application is suitable for being adopted when the UPS power supply system needs to be completely powered off for maintenance.

Description

Control circuit and control method

Technical Field

The embodiment of the application relates to the technical field of power supply and distribution, in particular to a control circuit and a control method.

Background

An Uninterruptible Power Supply (UPS) is a constant voltage and constant frequency Power Supply that includes an energy storage device and an inverter as a main component, and is mainly used to provide uninterrupted Power Supply for computer technology (IT) equipment. UPSs are generally classified into online UPSs, backup UPSs, and online interactive UPSs. The online UPS means that the ac voltage used by the load passes through the inverter circuit and the inverter is always in a working state regardless of the normal commercial power.

At present, a data center generally uses an online UPS, which generally includes a main circuit inverter circuit, a battery charging and discharging circuit, a static bypass, and an internal maintenance bypass, as shown in fig. 1, the online UPS normally operates in the main circuit inverter circuit, and supplies a regulated voltage to a load, and simultaneously performs floating charging on a battery in the online UPS. When the commercial power is interrupted (for example, an accident power failure), the online UPS continuously supplies 220V ac power to the load by using the battery in the online UPS through an inversion conversion method, so that the load can maintain normal operation and protect the software and hardware of the load from damage. When the inversion is unavailable, if the frequency and the phase of the alternating current output by the main circuit and the alternating current output by the bypass are the same, and the voltage amplitude difference is within a certain range, the UPS can realize uninterrupted switching to the static bypass, and when the host needs maintenance, the UPS can manually switch to the internal maintenance bypass. The general large and medium UPS host computer is provided with an internal maintenance bypass, but the UPS host computer needs to be completely powered off for maintenance and repair, and the problem is solved only by arranging an external maintenance bypass.

In order to avoid that a main circuit inversion circuit and an external maintenance bypass of an online UPS are simultaneously conducted to cause that a main circuit inversion output and a bypass power supply synchronously form a circulation current to damage components and parts and cause an IT load power supply interruption, in the prior art, an output switch of the main circuit inversion circuit and an output switch of the external maintenance bypass are generally interlocked to prevent the output switch of the UPS and the external maintenance bypass switch from being simultaneously switched on. According to the scheme, when the UPS needs to be completely powered off for maintenance, the output switch of the main circuit inversion loop needs to be disconnected firstly, and then the output switch of the external maintenance bypass needs to be closed, and the process can cause the power failure of the tail-end IT load, so that the IT service interruption is caused, and even the user data loss can be possibly caused. Therefore, the solutions in the prior art cannot ensure that the UPS power supply system is switched to the external maintenance bypass for maintenance and repair without interruption of the power supply of the end IT load.

Disclosure of Invention

The embodiment of the application provides a control circuit and a control method, which can enable a UPS power supply system to be uninterruptedly switched to an external maintenance bypass from a main circuit inverter circuit under the condition that the power supply of a tail-end IT load is not interrupted, thereby isolating, maintaining and maintaining a UPS, and preventing the UPS inverter power supply and the external maintenance bypass from supplying power in parallel caused by misoperation of personnel in the switching process of the main circuit.

In order to achieve the above purpose, the embodiment of the present application adopts the following technical solutions:

in a first aspect of the embodiments of the present application, a UPS control circuit is provided, where the control circuit is applied to a UPS power supply system, the UPS power supply system includes a UPS main circuit inversion loop, a static bypass, and an external maintenance bypass, an output end of the UPS main circuit inversion loop and an output end of the static bypass are connected to a first switch, the first switch is used to turn on or off the UPS main circuit inversion loop and the static bypass, an output end of the external maintenance bypass is connected to a second switch, the external maintenance bypass is used to turn on or off the external maintenance bypass, and the control circuit includes a first control circuit; the first control circuit comprises a first module circuit, a normally closed contact of a second switch, a closing coil of the second switch and an electric closing button of the second switch which are connected in series; the first module circuit comprises a normally open contact of a first switch and a normally closed contact of a first relay which are connected in series, and the normally closed contact of the first switch is connected with the normally open contact of the first switch and the normally closed contact of the first relay in parallel; the first relay is used for representing the working state of the UPS inverter, and when the UPS inverter is started, the normally closed contact of the first relay is disconnected. Therefore, the control circuit can realize that the IT load is not powered down through static bypass transition in the process of switching the UPS main circuit inversion loop to the external maintenance bypass by setting the interlocking design of the UPS inversion starting and the external maintenance bypass switch closing, and ensures that the UPS power supply system is switched to the external maintenance bypass for maintenance under the condition that the power supply of the tail IT load is not interrupted; meanwhile, when the main circuit inversion loop is switched on, the external maintenance bypass is ensured not to be switched on simultaneously, active anti-misoperation design is realized, the phenomenon that the main circuit output and the bypass output cannot be synchronized to form a circulating current due to manual misoperation is effectively prevented, and data loss caused by accidental interruption of a load power supply and equipment and personnel safety risks caused by electrical faults are avoided.

In a second aspect of the embodiments of the present application, a UPS control circuit is provided, where the control circuit is applied to a UPS power supply system, the UPS power supply system includes a UPS main circuit inversion loop, a static bypass, and an external maintenance bypass, an output end of the UPS main circuit inversion loop and an output end of the static bypass are connected to a first switch, the first switch is used to turn on or off the UPS main circuit inversion loop and the static bypass, an output end of the external maintenance bypass is connected to a second switch, the external maintenance bypass is used to turn on or off the external maintenance bypass, the control circuit includes a second control circuit, and the second control circuit includes a normally open contact of the first switch, a normally open contact of the second switch, a normally open contact of the first relay, and a work coil of the second relay, which are connected in series; the normally open contact of the second relay is connected with the UPS control panel, and when the normally open contact of the second relay is closed, a UPS inverter shutdown signal is transmitted to the UPS. Therefore, when the main circuit inverter circuit of the UPS power supply system is conducted, the situation that the main circuit inverter circuit of the UPS and the external maintenance bypass are conducted simultaneously to cause circulation due to manual active misoperation (pressing a manual closing button of the second switch body) can be prevented, and the design of passive misoperation prevention is achieved.

In a third aspect of the embodiments of the present application, a UPS control circuit is provided, where the control circuit is applied to a UPS power supply system, the UPS power supply system includes a UPS main circuit inversion loop, a static bypass, and an external maintenance bypass, an output end of the UPS main circuit inversion loop and an output end of the static bypass are connected to a first switch, the first switch is used to turn on or off the UPS main circuit inversion loop and the static bypass, an output end of the external maintenance bypass is connected to a second switch, the external maintenance bypass is used to turn on or off the external maintenance bypass, the control circuit includes a third control circuit, and the third control circuit includes a second module circuit and a work coil of a third relay, which are connected in series; the second module circuit comprises a normally open contact of a first switch and a normally closed contact of a second switch which are connected in series, and the normally closed contact of the first switch is connected with the normally open contact of the first switch and the normally closed contact of the second switch in parallel; the normally open contact of the third relay is connected with the UPS control panel, and when the normally open contact of the third relay is closed, the UPS inversion starting enabling signal is transmitted to the UPS. Therefore, when the external maintenance bypass is switched to the main circuit inversion loop, the load is not powered down through static bypass transition, and the UPS power supply system is switched to the main circuit inversion loop from the external maintenance bypass to supply power to the load under the condition that the power supply of the tail-end IT load is not interrupted; meanwhile, when the second switch of the external maintenance bypass and the first switch of the main circuit inverter circuit are both closed, the UPS inverter is not allowed to be started, and the phenomenon that the main circuit inverter circuit and the external maintenance bypass are simultaneously conducted to form a circulating current due to manual misoperation is effectively prevented.

In a fourth aspect of the embodiments of the present application, there is provided a UPS control circuit applied to a UPS power supply system including a main inverter circuit, a static bypass, an external service bypass, and a dummy load test circuit, wherein an output of the main inverter circuit and an output of the static bypass are connected to a first switch for turning on or off the main inverter circuit and the static bypass, an output of the external service bypass is connected to a second switch for turning on or off the external service bypass, an output of the dummy load test circuit is connected to a third switch for turning on or off the dummy load test circuit, the control circuit includes a fourth control circuit including an electric close button of the first switch, a normally closed contact of the third switch, and a close coil of the first switch connected in series, and the electric closing button of the third switch, the normally closed contact of the first switch and the closing coil of the third switch are connected in series. Therefore, by interlocking the third switch connected with the output end of the dummy load test loop with the first switch connected with the output end of the main circuit inverter loop, the situation that the external maintenance bypass and the main circuit inverter loop are simultaneously conducted to form a circulating current can be avoided when the dummy load test is carried out in the state that the external maintenance bypass is conducted, and the situation that the main circuit inverter loop is conducted to cause the overload of the UPS power distribution system can also be avoided when the dummy load test is carried out in the state that the external maintenance bypass is disconnected.

In a fifth aspect of the embodiments of the present application, a control method is provided, where the control method is applied to the control circuit of the first aspect, and the control method includes, in a case where the UPS inverter is in a startup state, the first switch is in a closed state, and an electric closing button of the second switch is closed, controlling a closing coil of the second switch not to be powered, so that the external maintenance bypass remains in an open state; and under the conditions that the first switch is in a breaking state or the UPS inverter is in a non-starting state and an electric closing button of the second switch is closed, the closing coil of the second switch is controlled to be electrified, so that the external maintenance bypass is conducted. The description of the effect of the fifth aspect may refer to the description of the effect of the first aspect, and is not repeated here.

In a sixth aspect of the embodiments of the present application, a control method is provided, where the control method is applied to the control circuit of the second aspect, and the control method includes, in a case where the first switch is in a closed state and the UPS inverter is in an activated state, and the second switch body manual closing button is closed, controlling a work coil of the UPS inverter closing signal relay to be powered on, and transmitting a UPS inverter closing signal to the UPS to instruct the UPS to close the inverter. The description of the effect of the sixth aspect may refer to the description of the effect of the second aspect, and is not repeated here.

In a seventh aspect of the embodiments of the present application, a control method is provided, where the control method is applied to the control circuit in the third aspect, and the control method includes, in a case where the first switch is in a closed state and the second switch is in an open state, controlling a work coil of the UPS inversion start enable signal relay to be energized so that the UPS satisfies a turn-on condition of the UPS inverter; under the condition that the first switch is in a breaking state, controlling a working coil of a starting condition signal relay of the UPS inverter to be electrified so that the UPS meets the starting condition of the UPS inverter; and under the condition that the first switch and the second switch are both in a closed state, controlling a working coil of the power-on condition signal relay of the UPS inverter not to be electrified so that the UPS does not meet the power-on condition of the UPS inverter. The description of the effect of the seventh aspect may refer to the description of the effect of the third aspect, and is not repeated here.

In an eighth aspect of embodiments of the present application, there is provided a control method applied to the control circuit of the fourth aspect, the control method including controlling the third switch to maintain an open state in a case where the first switch is in a closed state; and under the condition that the third switch is in a closed state, controlling the first switch to keep an open state. The description of the effect of the eighth aspect may refer to the description of the effect of the fourth aspect, and is not repeated here.

A ninth aspect of embodiments of the present application provides a control circuit comprising any two or more of the control circuits of the first, second, third and fourth aspects. The description of the effects of the ninth aspect may refer to the descriptions of the corresponding effects of the first to fourth aspects, and is not repeated here.

In a tenth aspect of the embodiments of the present application, there is provided a control method including any two or more of the control methods of the fifth aspect, the sixth aspect, the seventh aspect, and the eighth aspect. The description of the effect of the tenth aspect may refer to the description of the corresponding effect of the fifth aspect to the eighth aspect, and is not repeated here.

Drawings

Fig. 1 is a block diagram of a UPS power supply system provided in the prior art;

fig. 2 is a block diagram of a UPS power supply system according to an embodiment of the present disclosure;

FIG. 3 is a logic control diagram of a control circuit according to an embodiment of the present application;

FIG. 4 is a logic control diagram of another control circuit provided in an embodiment of the present application;

FIG. 5 is a logic control diagram of another control circuit provided in an embodiment of the present application;

fig. 6 is a block diagram of another UPS power supply system according to an embodiment of the present disclosure;

fig. 7 is a logic control diagram of another control circuit provided in the embodiments of the present application.

Detailed Description

It should be noted that, in the following embodiments of the present application, all the UPSs are online UPSs, and for convenience of description, they are referred to as UPSs.

Embodiments of the present application provide a control circuit for a UPS power supply system 10, see fig. 2, where the UPS power supply system 10 is connected between a utility power source and an end IT load for providing uninterrupted power to the end IT load.

The UPS power supply system 10 includes a main inverter circuit 101, a static bypass 102, and an external service bypass 103. The output end of the UPS main circuit inversion loop 101 and the output end of the static bypass 102 are connected to a first switch QF1, the first switch is used for switching on or off the UPS main circuit inversion loop 101 and the static bypass 102, the output end of the external maintenance bypass 103 is connected to a second switch QF2, and the second switch is used for switching on or off the external maintenance bypass 103. For example, the UPS power supply system in this application may include a parallel operation of multiple UPS hosts, and when the UPS power supply system includes a parallel operation of multiple UPS hosts, the first switch QF1 in this application is an output switch after the parallel operation of multiple UPSs.

The main circuit inversion circuit 101 is used for supplying alternating current of a power grid to an IT load for use after the alternating current is stabilized through a rectifier and an inverter when the commercial power input is normal; the static bypass 102 is used for uninterrupted switching of the UPS to the static bypass to supply power to the IT load when the inversion is unavailable; the external service bypass 103 is used to supply power to the IT load when the UPS is completely powered down for maintenance (e.g., cleaning or circuit breaker replacement).

The control circuit provided by the embodiment of the application is used for controlling the UPS power supply system 10, for example, the control circuit is used for controlling the main circuit inverter circuit 101 and the external maintenance bypass 103 to generate interlocking, so that the main circuit inverter circuit 101 and the external maintenance bypass 103 cannot be conducted simultaneously, and when the main circuit inverter circuit 101 and the external maintenance bypass 103 are conducted simultaneously, output is asynchronous to form a loop current, which damages components and parts and causes IT load power supply interruption. And the control circuit is used for controlling the UPS power supply system 10 to supply power to the end IT load uninterruptedly when the main circuit inverter circuit 101 is switched to the external maintenance bypass 103 due to various needs. The reason for switching the main inverter circuit 101 to the external service bypass 103 is not limited in the embodiment of the present application, and for example, a scenario of switching to the external service bypass when the UPS needs to be completely powered off for maintenance may be considered.

For example, the logic formula of the control circuit controlling the second switch QF2 to close is as follows:

wherein, QF2_YCIs the closing coil of the second switch QF2, SB2 is the electric closing button of the second switch,

is the first switch breaking position and is led out from the auxiliary normally closed contact of the first switch, QF1 is the first switch closing position and is led out from the auxiliary normally open contact of the first switch,

indicating an inverter shutdown state of the UPS.

Illustratively, in conjunction with fig. 2, as shown in fig. 3, the control circuit may include: a first control circuit 201. The first control circuit 201 may include a first module circuit, a normally closed contact of a second switch, a closing coil of the second switch, and an electric closing button of the second switch, which are connected in series.

The first module circuit may include a normally open contact of a first switch and a normally closed contact of a first relay connected in series, and a normally closed contact of the first switch connected in parallel with the normally open contact of the first switch and the normally closed contact of the first relay.

The first relay is used for representing the working state of the UPS inverter, and when the UPS inverter is started, the normally closed contact of the first relay is disconnected.

For example, the operating state of the UPS inverter in the embodiment of the present application is detected and controlled by the UPS control board, so that the detected on and off states of the UPS inverter are provided to the digital output signal interface, and the digital input signal of the remote on/off device is also received to turn on and off the UPS inverter.

The following describes in detail the process of controlling the UPS power supply system 10 to supply power to the end IT loads without interruption during the switching of the main inverter circuit 101 to the external service bypass 103 by the first control circuit 201.

Referring to fig. 2, when the main UPS inverter circuit 101 is powered on to supply power to a load, the first switch QF1 is closed, if the UPS needs to be completely powered off for maintenance, the UPS inverter is first turned off, the UPS main unit automatically switches to the static bypass 102 to supply power to the load, at this time, the electric closing button SB2 of the second switch is closed, the external maintenance bypass 103 is turned on, the static bypass 102 and the external maintenance bypass 103 are connected in parallel to supply power to an IT load, then the static bypass 102 is turned off, the external maintenance bypass 103 completely supplies power to the IT load, and at this time, the UPS can be completely powered off to perform operations such as cleaning maintenance or circuit breaker replacement.

When the UPS is completely powered off for maintenance, because the first switch QF1 of the UPS main circuit inverter circuit 101 and the second switch QF2 of the external maintenance bypass 103 in the first control circuit do not have an interlocking relationship, when the main circuit inverter circuit 101 is switched to the external maintenance bypass 103, the static bypass 102 can be used for transition to prevent the load from being powered off. Therefore, the control circuit in the embodiment of the application can enable the UPS power supply system to be switched to the external maintenance bypass for maintenance under the condition that the power supply of the terminal IT load is not interrupted.

The following describes in detail a process of preventing the main inverter circuit 101 and the external service bypass from being simultaneously turned on if the electric switch-on button SB2 of the second switch is pressed by a human error when the main inverter circuit 101 of the UPS is turned on to supply power to the IT load, and the first control circuit 201 controls the external service bypass 103 to be in the off state.

For example, referring to fig. 2, when the main circuit inversion circuit 101 of the UPS is turned on, the first switch QF1 is closed, the UPS supplies the ac power of the power grid to the load after the ac power is stabilized by the rectifier and the inverter, and when the UPS inverter is turned on, the working coil of the first relay 1KA is electrified, the normally closed contact of the first relay 1KA in the first control circuit 201 is disconnected, and since the main circuit inversion circuit 101 is turned on, the first switch QF1 is closed, the normally closed contact of the first switch QF1 is disconnected, and the normally open contact of the first switch QF1 is closed, when the main circuit inversion circuit of the UPS is turned on to supply power to the load, the normally closed contact of the first relay 1KA in the first module circuit and the normally closed contact of the first switch QF1 are both in an open state, so that the first module circuit is not turned on. At this time, if the user presses the electric closing button SB2 of the second switch in the external service bypass, the first module circuit is not turned on, so the closing coil of the second switch QF2 is not energized, and the external service bypass 103 is not turned on.

Therefore, the first control circuit 201 in the embodiment of the present application can prevent the power-on coil of the first switch QF2 in the external maintenance bypass 103 from being electrified even if the user presses the power-on button SB2 of the second switch in the external maintenance bypass 103 by mistake when the main inverter circuit 101 is turned on, so that the external maintenance bypass 103 is not turned on, that is, the main inverter circuit 101 and the external maintenance bypass 103 are not turned on at the same time, and therefore, the first control circuit 201 in the embodiment of the present application can prevent the external maintenance bypass 103 from being turned on by mistake when the main inverter circuit 101 is turned on, thereby effectively preventing the main inverter circuit of the UPS and the external maintenance bypass from being turned on at the same time to cause a circulating current.

The control circuit that this application embodiment provided through set up the interlocking design that UPS contravariant start-up and external maintenance bypass switched on in first control circuit, can switch to external maintenance bypass in-process at UPS main road contravariant return circuit, realize through static bypass transition that the IT load does not fall the power, guarantee under the circumstances that terminal IT load power supply is uninterrupted, make UPS power supply system switch to external maintenance bypass and maintain. Meanwhile, when the main circuit inversion loop is switched on, the external maintenance bypass is ensured not to be switched on simultaneously, active anti-misoperation design is realized, the phenomenon that the main circuit output and the bypass output cannot be synchronized to form a circulating current due to manual misoperation is effectively prevented, and data loss caused by accidental interruption of a load power supply and equipment and personnel safety risks caused by electrical faults are avoided.

In another embodiment of the present application, the control circuit may be further configured to prevent the second switch body from being manually switched on by the switch-on button when the main circuit inverter circuit 101 is switched on, so that the inverter output and the bypass power supply form a circular current at different synchronization. The manual closing button of the second switch body belongs to one part of the mechanical structure of the circuit breaker and is not controlled by the control loop.

With reference to fig. 2, as shown in fig. 4, the control circuit may further include: a second control circuit 202, wherein the second control circuit 202 may comprise a normally open contact of the first switch, a normally open contact of the second switch, a normally open contact of the first relay, and a working coil of the second relay connected in series.

And when the normally open contact of the second relay is closed, a UPS inverter shutdown signal is transmitted to the UPS. It can be understood that the second relay is a UPS inverter shutdown signal relay, and when the work coil of the second relay is energized, the normally open contact of the second relay is closed, sending a UPS inverter shutdown signal to the UPS to instruct the UPS host to shut down the inverter.

The following detailed description describes a process of preventing the main inverter circuit 101 and the external maintenance bypass 103 from being turned on simultaneously by controlling the UPS inverter to be turned off by the second control circuit 202 if the user mistakenly presses the manual switch-on button of the second switch QF2 to switch on the main inverter circuit 101.

Referring to fig. 2, in combination with the first control circuit 201 shown in fig. 3 and the second control circuit 202 shown in fig. 4, when the main UPS inversion circuit 101 is turned on, the first switch QF1 is closed, the normally open contact of the first switch QF1 is closed, the normally open contact of the first relay 1KA is closed, at this time, the manual closing button of the second switch QF2 body is pressed to close, the normally open contact of the QF2 is closed, and since the normally open contacts of the first switch QF1, the second switch QF2 and the first relay 1KA are all closed, the working coil of the second relay 2KA in the second control circuit 202 is powered on, the normally open contact of the second relay 2KA is closed, a UPS inverter stop signal is sent to the UPS, and the UPS turns off the inversion after receiving the UPS inverter stop signal.

Therefore, in the embodiment of the present application, even if the user presses the manual closing button of the second switch QF2 to close the UPS when the UPS main circuit inverter circuit 101 is turned on, the second control circuit 202 may send the UPS inverter shutdown signal to the UPS to shut down the inversion of the main circuit, so as to prevent the damage to the components due to the circulation caused by the simultaneous conduction of the UPS main circuit inverter circuit and the external maintenance bypass.

The second control circuit provided by the embodiment of the application can prevent the UPS main circuit inversion loop and the external maintenance bypass from being simultaneously conducted to cause circulation current due to human misoperation when the main circuit inversion loop 101 of the UPS power supply system is conducted, realizes passive misoperation prevention design, and avoids equipment and personnel safety risks caused by electrical faults.

In another embodiment of the present application, the control circuit is further configured to control that the external maintenance bypass 103 and the main circuit inverter circuit 101 cannot be turned on simultaneously, so as to avoid that when the main circuit inverter circuit 101 and the external maintenance bypass 103 are turned on simultaneously, output is asynchronous to form a circulation current, which damages components and devices and causes IT load power supply interruption. And the control circuit is further configured to control the UPS power supply system 10 to supply power to the end IT load without interruption when the external service bypass 103 is switched to the main circuit inverter circuit 101 according to various needs. The reason why the external repair bypass 103 is switched to the main circuit inverter circuit 101 in the embodiment of the present application is not limited, and for example, the reason may be a scenario where the UPS is switched to the main circuit inverter circuit 101 after completing the power-off maintenance operation.

For example, the logic formula of the control circuit for controlling the UPS inverter to start up is as follows:

wherein, the UPS_RCIndicating that the UPS inverter is inverted and started, SR is an inversion starting signal of the UPS power supply system, QF1 is a first switch closing position and is led out from an auxiliary normally open contact of a first switch,

is an open position of the first switch and is led out from an auxiliary normally closed contact of the first switch,

and the second switch is an open position and is led out from an auxiliary normally closed contact of the second switch.

Illustratively, in conjunction with fig. 2, as shown in fig. 5, the control circuit may further include: a third control circuit 203, the third control circuit 203 may include a second module circuit and a work coil of a third relay connected in series.

The second module circuit may include a normally open contact of the first switch and a normally closed contact of the second switch connected in series, and a normally closed contact of the first switch connected in parallel with the normally open contact of the first switch and the normally closed contact of the second switch.

The normally open contact of the third relay is connected with the UPS control panel, and when the normally open contact of the third relay is closed, the UPS inversion starting enabling signal is transmitted to the UPS. It can be understood that the third relay is a startup condition signal relay of the UPS inverter, when a working coil of the third relay is electrified, a normally open contact of the third relay is closed, a UPS inversion start enabling signal is transmitted to the UPS, the condition of UPS inversion start is met at the moment, and the inverter can be started.

The following describes in detail the process of controlling the UPS power supply system 10 to supply power to the end IT loads without interruption by the third control circuit 203 during the process of switching the external service bypass 103 to the main circuit inverter circuit 101.

Illustratively, referring to fig. 2, when the external maintenance bypass 103 is turned on to supply power to the load, the second switch QF2 is closed, if the UPS power-off maintenance operation is completed, and the external maintenance bypass 103 needs to be switched back to the main circuit inverter circuit 101 to supply power to the load, first, the first switch QF1 is closed, the static bypass 102 is turned on, the load is supplied by the static bypass 102 and the external maintenance bypass 103 in parallel, then the second switch QF2 is closed to disconnect the external maintenance bypass 103, the load is supplied by the static bypass 102 alone, then the UPS inverter is turned on again to switch the power supply system from the static bypass 102 to the UPS main circuit inverter circuit 101 to supply power to the load, and the external maintenance bypass 103 is switched to the main circuit inverter circuit 101.

When the external maintenance bypass 103 is switched back to the main circuit inverter circuit 101 in the embodiment of the application, because the first switch QF1 of the UPS main circuit inverter circuit 101 and the second switch QF2 of the external maintenance bypass 103 do not have an interlocking relationship, when the external maintenance bypass 103 is switched to the main circuit inverter circuit 101, the static bypass 102 can be used for realizing the transition without power failure of the load. Therefore, the control circuit in the embodiment of the application can switch the UPS power supply system from the external maintenance bypass back to the main circuit inversion loop to supply power to the load under the condition that the power supply of the terminal IT load is not interrupted.

The following details are provided to describe a process of preventing the main circuit inverter circuit 101 and the external maintenance bypass circuit from being simultaneously turned on by controlling the main circuit inverter circuit 101 not to be turned on if the UPS inverter is turned on by a human error when the external maintenance bypass circuit 103 is turned on to supply power to the IT load.

For example, referring to fig. 2, when the UPS is completely powered down for maintenance, the external maintenance bypass 103 is conducted to supply power to the load, the second switch QF2 is closed, and in conjunction with the third control circuit 203 shown in fig. 5, when the external maintenance bypass 103 is conducted, the second switch QF2 in the second module circuit is closed, and if the first switch QF1 is in a closed state, since the normally closed contact of the second switch QF2 in the second module circuit is open, the normally open contact of the first switch QF1 is closed, and the normally closed contact of the first switch QF1 is open, the second module circuit is not conducted, and the working coil of the third relay 3KA is not powered, so that the condition of UPS inversion starting is not satisfied.

Therefore, in the embodiment of the present application, the third control circuit 203 is turned on in the external maintenance bypass 103, when the first switch QF1 is closed, the condition for the UPS to start the UPS inverter is not satisfied, and the UPS cannot start the UPS inverter, so that when both the second switch QF2 and the first switch QF1 are closed, the UPS inverter is not allowed to start, the UPS inverter is prevented from being turned on by human misoperation, and a circulating current caused by the simultaneous turn-on of the main circuit inverter circuit of the UPS and the external maintenance bypass is effectively prevented.

Further, with reference to the third control circuit 203 shown in fig. 5, in an aspect of the embodiment of the present application, when the second switch QF2 of the external maintenance bypass 103 is disconnected, the normally closed contact of the second switch QF2 is still in a closed state, at this time, no matter whether the first switch QF1 is closed, the second module circuit is turned on, the working coil of the third relay 3KA is charged, the normally open contact of the third relay is closed, a condition of starting up the UPS inverter is met, and at this time, the inverter is started by pressing the switch for starting up the UPS inverter. On the other hand, when the external maintenance bypass 103 is turned on, the second switch QF2 is in a closed state, the normally closed contact of the second switch QF2 is opened, and at this time, if the first switch is in an opened state, the second module circuit is still turned on, the working coil of the third relay 3KA is electrified, and the condition of UPS inversion starting is also met. For example, the condition may be that the first switch QF1 is turned off, and when the external maintenance bypass 103 supplies power to the end IT load, the UPS inverter start condition is satisfied, and the inverter may be started to perform the dummy load test.

Therefore, the third control circuit of the embodiment of the application judges whether the UPS meets the condition of inversion starting, sends a UPS inversion starting enabling signal to the UPS by judging the on and off states of the second switch in the external maintenance bypass, and can start inversion through the inversion starting switch when the inversion starting condition is met.

The third control circuit provided by the embodiment of the application can realize that the load is not powered down through static bypass transition when the external maintenance bypass is switched back to the main circuit inverter circuit, and ensures that the UPS power supply system is switched to the main circuit inverter circuit from the external maintenance bypass to supply power to the load under the condition that the power supply of the tail-end IT load is not interrupted. Meanwhile, when the external maintenance bypass is conducted to supply power to the load and the first switch of the main circuit inversion loop is closed, the UPS inversion starting-up is not allowed, the situation that the main circuit inversion loop and the external maintenance bypass are conducted simultaneously to form circulation current due to manual misoperation is effectively prevented, and data loss caused by accidental interruption of a load power supply and equipment and personnel safety risks caused by electrical faults are avoided.

Fig. 6 is a block diagram of another UPS power supply system 20 according to an embodiment of the present application, and here, an application scenario of the control circuit according to the embodiment of the present application is illustrated only by the block diagram shown in fig. 6. The UPS power supply system 20 further includes a dummy load test circuit 104 in addition to the circuit shown in fig. 2, where the dummy load test circuit 104 is configured to perform a discharge test on the battery pack of the UPS periodically to evaluate the battery status, and can perform a preventive replacement on a battery with significantly degraded performance to avoid a power interruption of the end load due to a battery discharge fault; and the replaced battery can be comprehensively tested to evaluate the performance of the battery to meet the system requirements.

Illustratively, the output of the dummy load test loop 104 is connected to a third switch QF3 for turning on or off the dummy load test loop 104. As shown in fig. 6, the broken line in fig. 6 represents the dummy load test loop 104, and the UPS host converts the dc power of the battery pack into ac power through the inverter, and performs the dummy load test through the third switch QF 3.

In another embodiment of the present application, the control circuit may be further configured to control the third switch of the dummy load test circuit to maintain an open state when the first switch of the main circuit inverter circuit is in a closed state, or control the first switch of the main circuit inverter circuit to maintain an open state when the third switch of the dummy load test circuit is in a closed state, so as to avoid a situation where the third switch of the external maintenance bypass and the first switch of the main circuit inverter circuit are closed simultaneously, which may cause a circulating current or overload of the UPS power distribution system.

Referring to fig. 6, as shown in fig. 7, the control circuit may further include: and a fourth control circuit 204, where the fourth control circuit 204 may include an electric closing button of the first switch, a normally closed contact of the third switch, and a closing coil of the first switch connected in series, and an electric closing button of the third switch, a normally closed contact of the first switch, and a closing coil of the third switch connected in series.

For example, as shown in fig. 7, the electric closing button of the first switch, the normally closed contact of the third switch, and the closing coil of the first switch connected in series may be connected in parallel with the electric closing button of the third switch, the normally closed contact of the first switch, and the closing coil of the third switch connected in series.

The following describes in detail a process in which when the dummy load test is performed in a state in which the external maintenance bypass 103 is turned on, the fourth control circuit 204 controls the output switch QF1 of the main inverter circuit 101 to be kept in an off state, thereby preventing the main inverter circuit 101 and the external maintenance bypass 103 from being turned on simultaneously.

For example, referring to fig. 6, in combination with the fourth control circuit 204 shown in fig. 7, since the first switch QF1 connected to the output terminal of the main inverter circuit 101 and the third switch QF3 connected to the output terminal of the dummy load test circuit 104 are interlocked, when the UPS performs the dummy load test in a state where the external service bypass 103 is turned on, the electric closing button SB3 of the third switch in the dummy load test circuit 104 is closed, the closing coil of the third switch QF3 is charged, the normally closed contact of the third switch QF3 is opened, the closing coil of the first switch QF1 is not charged, and the main inverter circuit 101 is not turned on.

Therefore, in the embodiment of the application, when the dummy load test is performed in the state where the external maintenance bypass 103 is turned on, because the first switch QF1 connected to the output end of the main circuit inverter circuit 101 and the third switch QF3 connected to the output end of the dummy load test circuit 104 are interlocked, when the dummy load test is performed in the state where the external maintenance bypass 103 is turned on, the main circuit inverter circuit 101 is not turned on, so that it can be ensured that the external maintenance bypass 103 and the main circuit inverter circuit 101 are not turned on at the same time, and it is avoided that the main circuit output and the bypass output form a loop current at different steps.

As will be described in detail below, when the dummy load test is performed in a state where the external service bypass 103 is disconnected, the fourth control circuit 204 controls the output switch QF1 of the main inverter circuit 101 to maintain the disconnected state, so as to prevent the UPS power distribution system from being overloaded.

Illustratively, referring to fig. 6 in conjunction with the fourth control circuit 204 shown in fig. 7, when the UPS performs a dummy load test with the external service bypass 103 disconnected, the power-operated closing button SB3 of the third switch in the dummy load test circuit 104 is closed, the closing coil of the third switch QF3 is charged, the normally closed contact of the third switch QF3 is opened, the closing coil of the first switch QF1 is not charged, and the main inverting circuit 101 is not turned on.

Therefore, in the embodiment of the application, when the dummy load test is performed in a state where the external maintenance bypass 103 is disconnected, because the closing coil of the first switch QF1 connected to the output end of the main circuit inverter circuit 101 is in a power-off state, the output end of the main circuit inverter circuit 101 is not conducted, power can be ensured not to be supplied to the end IT load during the dummy load test, and the UPS power distribution system is prevented from being overloaded.

In the following detailed description, after the main circuit inverter circuit 101 is turned on in the state where the external maintenance bypass 103 is disconnected, the fourth control circuit 204 controls the output switch QF3 of the dummy load test circuit 104 to maintain the disconnected state, so as to avoid overloading the UPS power distribution system.

Illustratively, referring to fig. 6 in conjunction with the fourth control circuit 204 shown in fig. 7, when the external service bypass 103 of the UPS power supply system is kept open, the electric closing button SB1 of the first switch is closed, the closing coil of the first switch QF1 is charged, the normally closed contact of QF1 is open, so that the closing coil of the third switch QF3 is not charged, and the dummy load test circuit 104 is not conducted.

Therefore, in the embodiment of the application, after the main circuit inverter circuit 101 is turned on in the state where the external maintenance bypass 103 is disconnected, since the closing coil of the third switch connected to the output end of the dummy load test circuit 104 is not powered, the dummy load test circuit 104 is not turned on, and it can be ensured that the dummy load test circuit 104 is not turned on after the main circuit inverter circuit is turned on in the state where the external maintenance bypass is kept disconnected, thereby preventing the UPS power distribution system from being overloaded.

The fourth control circuit provided by the embodiment of the application, through interlocking the third switch connected with the output end of the dummy load test loop with the first switch connected with the output end of the main circuit inverter loop, when the dummy load test can be performed in a state that the external maintenance bypass is switched on, the external maintenance bypass and the main circuit inverter loop are prevented from being simultaneously switched on to form a circulation current, and when the dummy load test can be performed in a state that the external maintenance bypass is switched off, the main circuit inverter loop is prevented from being switched on to cause overload of the UPS power distribution system.

For example, the present embodiment may further provide a control circuit, where the control circuit may include any two or more control circuits of the first control circuit 201, the second control circuit 202, the third control circuit 203, and the fourth control circuit 204 in the above embodiments, and is used to control the UPS power supply system.

The embodiment of the present application further provides a control method, which is applied to the UPS power supply system 10 shown in fig. 2, and the method can control the UPS power supply system 10 to uninterruptedly supply power to the end IT load when the main circuit inverter circuit 101 is switched to the external maintenance bypass 103; meanwhile, when the main circuit inverter circuit 101 is conducted, the external maintenance bypass 103 is controlled not to be conducted at the same time, and the condition that when the main circuit inverter circuit 101 and the external maintenance bypass 103 are conducted at the same time, output is asynchronous to form a circulating current is avoided.

The control method comprises the following steps: under the conditions that the UPS inverter is in a starting state, the first switch is in a closed state, and an electric closing button of the second switch is closed, controlling a closing coil of the second switch not to be electrified so that the external maintenance bypass keeps a disconnected state; and under the conditions that the first switch is in a breaking state or the UPS inverter is in a non-starting state and an electric closing button of the second switch is closed, the closing coil of the second switch is controlled to be electrified, so that the external maintenance bypass is conducted.

The specific control manner of the control method provided in the embodiment of the present application has been described in detail in the foregoing embodiment, and is not described herein again.

According to the control method provided by the embodiment of the application, the IT load is not powered off through static bypass transition in the process that the UPS main circuit inverter loop is switched to the external maintenance bypass, and the UPS power supply system is switched to the external maintenance bypass to be maintained under the condition that the power supply of the tail-end IT load is not interrupted. Meanwhile, when the main circuit inversion loop is switched on, the external maintenance bypass is ensured not to be switched on simultaneously, active anti-misoperation design is realized, the phenomenon that the main circuit output and the bypass output cannot be synchronized to form a circulating current due to manual misoperation is effectively prevented, and data loss caused by accidental interruption of a load power supply and equipment and personnel safety risks caused by electrical faults are avoided.

In another embodiment of the present application, the control method may prevent the switching-on of the main circuit inverter circuit 101 by the manual switch-on button of the second switch body, which may cause the inverter output and the bypass power supply to form a circular current at different synchronization.

The control method may include: and under the condition that the first switch is in a closed state, the UPS inverter is in a starting state, and the manual closing button of the second switch body is closed, controlling a working coil of the UPS inverter closing signal relay to be electrified, and transmitting a UPS inverter closing signal to the UPS so as to indicate the UPS to close the inverter.

The control method provided by the embodiment of the application can prevent the UPS main circuit inversion loop and the external maintenance bypass from being simultaneously conducted to cause circulation current due to manual misoperation when the main circuit inversion loop 101 of the UPS power supply system is conducted, so that the passive misoperation prevention design is realized, and the equipment and personnel safety risks caused by electrical faults are avoided.

In another embodiment of the present application, the control method may control the UPS power supply system 10 to uninterruptedly supply power to the end IT load when the external maintenance bypass 103 is switched to the main inverter circuit 101; meanwhile, when the external maintenance bypass 103 is conducted, the main circuit inverter circuit 101 is controlled not to be conducted at the same time, and the phenomenon that when the main circuit inverter circuit 101 and the external maintenance bypass 103 are conducted at the same time, output is asynchronous to form a circulating current is avoided.

The control method may include: under the condition that the first switch is in a closed state and the second switch is in a breaking state, controlling a working coil of a UPS inversion starting enabling signal relay to be electrified, transmitting a UPS inversion starting enabling signal to the UPS, and meeting the starting condition of a UPS inverter at the moment; under the condition that the first switch is in a breaking state, controlling a working coil of a starting condition signal relay of the UPS inverter to be electrified, and transmitting a UPS inversion starting enabling signal to the UPS, wherein the starting condition of the UPS inverter is met; and under the condition that the first switch and the second switch are both in a closed state, controlling a working coil of the UPS inverter starting condition signal relay not to be electrified, and at the moment, not meeting the starting condition of the UPS inverter.

The control method provided by the embodiment of the application can realize no power failure of the load through static bypass transition when the external maintenance bypass is switched back to the main circuit inverter circuit, and ensure that the UPS power supply system is switched to the main circuit inverter circuit from the external maintenance bypass to supply power to the load under the condition that the power supply of the tail-end IT load is not interrupted. Meanwhile, when the external maintenance bypass is conducted to supply power to the load and the first switch of the main circuit inversion loop is closed, the UPS inversion starting-up is not allowed, the situation that the main circuit inversion loop and the external maintenance bypass are conducted simultaneously to form circulation current due to manual misoperation is effectively prevented, and data loss caused by accidental interruption of a load power supply and equipment and personnel safety risks caused by electrical faults are avoided.

In yet another embodiment of the present application, a control method is provided, which is applied to the UPS power supply system 20 shown in fig. 6, and the control method can further control that the third switch of the external service bypass and the first switch of the main circuit inverter loop cannot be closed at the same time.

The method can comprise the following steps: under the condition that the first switch is in a closed state, controlling the third switch to keep an open state; and under the condition that the third switch is in a closed state, controlling the first switch to keep an open state.

According to the control method provided by the embodiment of the application, the third switch connected with the output end of the dummy load test loop is interlocked with the first switch connected with the output end of the main circuit inversion loop, so that when the dummy load test is carried out in the state that the external maintenance bypass is switched on, the situation that the external maintenance bypass and the main circuit inversion loop are switched on simultaneously to form a circulation current is avoided, and when the dummy load test is carried out in the state that the external maintenance bypass is switched off, the situation that the main circuit inversion loop is switched on to cause the overload of the UPS power distribution system is avoided.

For example, the embodiment of the present application may further provide a control method, where the control method may include any two or more control methods in the foregoing embodiments, for controlling the UPS power supply system.

For example, in the embodiments of the present application, a circuit breaker is used as an example for the first switch, the second switch, and the third switch. The circuit breaker comprises a conductive part, a vacuum arc-extinguishing chamber, an insulating part, a transmission part, a frame and an operating mechanism, wherein in the switching-on process, when a switching-on coil of the operating mechanism is electrified, a switching-on iron core is attracted, and a movable conductive rod of the vacuum arc-extinguishing chamber moves through a connecting lever and a connecting rod to switch on the circuit breaker; in the process of opening, when an opening coil of the operating mechanism is electrified, the opening iron core is attracted, so that the locking notch is released, and the breaker is quickly disconnected under the action of an opening spring. When the switch is opened, the contact in the open state is called a normally open contact, the contact in the closed state is called a normally closed contact, the normally open contact of the circuit breaker is closed after the coil of the circuit breaker is electrified, and the normally closed contact of the circuit breaker is opened after the coil of the circuit breaker is electrified. The relay in the embodiment of the application can comprise an iron core, a coil, an armature, a contact reed and other components, when certain voltage is applied to two ends of the coil, certain current flows in the coil, so that an electromagnetic effect is generated, the armature overcomes the tension of a return spring under the attraction effect of electromagnetic force and is attracted to the iron core, so that a normally closed contact and a normally open contact of the armature are driven, the normally closed contact is disconnected, and the normally open contact is closed; when the coil is powered off, the electromagnetic attraction force disappears, the armature returns to the original position under the counterforce of the spring, the normally closed contact is closed, and the normally open contact is opened.

It will be appreciated that fig. 2 and 6 in the embodiments of the present application are merely exemplary, and that in practice, a UPS power distribution system may include more or fewer components than those shown in fig. 2 and 6, for example, a filter for filtering input AC power and providing filtered AC power to a rectifier, or an isolation transformer for increasing or decreasing the voltage from the inverter AC power and for providing isolation between the load and the UPS, or an internal service bypass for powering an end load when maintenance is required by the host, in which case the UPS may not be fully powered down; the structures shown in fig. 2 and 6 do not set any limit to the power supply and distribution system applied to the embodiments of the present application.

Those skilled in the art will recognize that, in one or more of the examples described above, the functions described in this invention may be implemented in hardware, software, firmware, or any combination thereof. When implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a general purpose or special purpose computer.

The above-mentioned embodiments, objects, technical solutions and advantages of the present invention are further described in detail, it should be understood that the above-mentioned embodiments are only exemplary embodiments of the present invention, and are not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements and the like made on the basis of the technical solutions of the present invention should be included in the scope of the present invention.

Claims

1. A control circuit is applied to a UPS power supply system, the UPS power supply system comprises a UPS main circuit inversion loop, a static bypass and an external maintenance bypass, the output end of the UPS main circuit inversion loop and the output end of the static bypass are connected with a first switch, the first switch is used for conducting or disconnecting the UPS main circuit inversion loop and the static bypass, the output end of the external maintenance bypass is connected with a second switch, and the second switch is used for conducting or disconnecting the external maintenance bypass, and the control circuit comprises a first control circuit;

the first control circuit comprises a first module circuit, a normally closed contact of the second switch, a closing coil of the second switch and an electric closing button of the second switch which are connected in series;

the first module circuit comprises a normally open contact of a first switch and a normally closed contact of a first relay which are connected in series, and the normally closed contact of the first switch is connected with the normally open contact of the first switch and the normally closed contact of the first relay in parallel;

the first relay is used for representing the working state of the UPS inverter, and when the UPS inverter is started, the normally closed contact of the first relay is disconnected;

the control circuit further comprises a second control circuit, wherein the second control circuit comprises a normally open contact of the first switch, a normally open contact of the second switch, a normally open contact of the first relay and a working coil of the second relay which are connected in series;

and when the normally open contact of the second relay is closed, the UPS inverter shutdown signal is transmitted to the UPS.

2. The control circuit of claim 1, further comprising a third control circuit,

the third control circuit comprises a second module circuit and a working coil of a third relay which are connected in series;

the second module circuit comprises a normally open contact of the first switch and a normally closed contact of the second switch which are connected in series, and the normally closed contact of the first switch is connected with the normally open contact of the first switch and the normally closed contact of the second switch in parallel;

the normally open contact of the third relay is connected with the UPS control panel, and when the normally open contact of the third relay is closed, the UPS inverter starting enabling signal is transmitted to the UPS.

3. The control circuit of any of claims 1-2, wherein the UPS power supply system further comprises a dummy load test loop, wherein an output of the dummy load test loop is connected to a third switch, the third switch is configured to turn on or off the dummy load test loop, the control circuit further comprises a fourth control circuit,

the fourth control circuit comprises an electric closing button of the first switch, a normally closed contact of the third switch and a closing coil of the first switch which are connected in series, and the electric closing button of the third switch, the normally closed contact of the first switch and the closing coil of the third switch which are connected in series.

4. A control method applied to the control circuit of claim 1, the control method comprising,

when the UPS inverter is in a starting state, the first switch is in a closed state, and an electric closing button of the second switch is closed, controlling a closing coil of the second switch to be not electrified so that the external maintenance bypass keeps an open state;

when the first switch is in a breaking state or the UPS inverter is in a non-starting state and an electric closing button of the second switch is closed, controlling a closing coil of the second switch to be electrified so as to enable the external maintenance bypass to be conducted;

the control method further comprises the step of controlling a working coil of a UPS inverter shutdown signal relay to be electrified and transmitting a UPS inverter shutdown signal to the UPS to indicate the UPS to shut down the inverter under the condition that the first switch is in a closed state, the UPS inverter is in a starting state and the second switch body manual closing button is closed.

5. The control method according to claim 4, characterized by further comprising,

under the condition that the first switch is in a closed state and the second switch is in a breaking state, controlling a working coil of a UPS inversion starting enabling signal relay to be electrified and transmitting a UPS inversion starting enabling signal to the UPS;

under the condition that the first switch is in a breaking state, controlling a working coil of a starting condition signal relay of the UPS inverter to be electrified and transmitting a UPS inversion starting enabling signal to the UPS;

and under the condition that the first switch and the second switch are both in a closed state, controlling a working coil of the UPS inverter starting condition signal relay not to be electrified.

6. The control method according to any of claims 4-5, wherein the UPS power supply system further comprises a dummy load test loop, an output terminal of the dummy load test loop is connected with a third switch, the third switch is used for conducting or breaking the dummy load test loop, and the control method further comprises controlling the third switch to keep an open state when the first switch is in a closed state; and under the condition that the third switch is in a closed state, controlling the first switch to keep an open state.