An inverter bypass switching system for UPS power supply

Abstract

The invention discloses an inverter bypass switching system for a UPS power supply, which comprises a main control module, a bypass module, an inverter module, an output module and a static transfer switch; the output neutral line of the output module, the bypass neutral line of the bypass module and the inverter neutral line of the inverter module are connected; the static transfer switch comprises a bidirectional thyristor and a conversion type magnetic latching relay; the first main electrode of the bidirectional thyristor and the reset contact of the conversion type magnetic latching relay are connected to the bypass live line of the bypass module, the second main electrode of the bidirectional thyristor is connected to the inverter live line of the inverter module, and the middle contact of the conversion type magnetic latching relay is connected to the output live line of the output module; the main control module controls the on and off of the bidirectional thyristor and controls the conversion type magnetic latching relay to act and reset. The invention can improve the stability and reliability of the UPS power supply when switching between the inverter output mode and the bypass output mode, and can reduce the overall volume of the UPS power supply and improve the overall efficiency of the UPS power supply.

Description

Technical Field

[0001] The invention relates to the field of UPS power supply, in particular to an inverter bypass switching system of a UPS power supply. Background Art

[0002] Uninterruptible power supply (also known as UPS power supply) is mainly composed of rectifier, inverter, bypass unit, charging power supply, battery system, etc. Among them, the bypass unit is an important component of UPS power supply.

[0003] The current UPS power supply output mode is bypass output mode or inverter output mode, mainly in the following situations:

[0004] 1. The UPS power supply is powered on but the inverter is not turned on. At this time, the UPS power supply remains in bypass output mode;

[0005] 2. The UPS power supply is powered on, the inverter is turned on and the inverter is normal, and the UPS power supply is switched to the inverter output mode;

[0006] 3. After the UPS power supply is in normal inverter operation, if the input mains power is suddenly cut off, the UPS power supply will be inverted by the battery; when the battery power reaches the battery low voltage protection point, the UPS power supply will switch to bypass output mode;

[0007] 4. After the input mains power is cut off and the battery inverter is under-voltage protected, if the mains power is restored, the UPS power will start automatically and after judging that the inverter is normal, the UPS power will switch to the inverter output mode;

[0008] 5. When the UPS power supply has abnormal phenomena such as inverter output overload, inverter output overvoltage, inverter overtemperature, excessive ambient temperature, inverter failure, etc., the UPS power supply switches to bypass output mode;

[0009] 6. When the UPS power supply needs to be repaired, the UPS power supply must also be switched to bypass output mode in advance.

[0010] As can be seen from the above, the switching reliability, safety, switching time and overall efficiency of the UPS between the inverter output mode and the bypass output mode have a great impact on the failure rate of the UPS power supply. Therefore, it is particularly important to ensure that the switching time of the UPS power supply is short when switching between the bypass output mode and the inverter output mode, that the load disturbance is small during switching, and that the overall efficiency of the UPS power supply is improved to improve the reliability during switching.

[0011] Currently, there are two forms of switching between bypass output mode and inverter output mode for UPS power supplies on the market.

[0012] The first switching mode uses thyristor as the main switch for switching between bypass output mode and inverter output mode; the first switching mode has the characteristics of short response time and short switching time. The switching time is only the sum of the detection circuit reaction time and the thyristor conduction time, usually less than 0.5ms. However, the inherent disadvantages of the first switching mode are: the thyristor has a junction voltage drop (1~2V), so when the load current flows through the thyristor for a long time, the thyristor will consume the energy of the inverter, and the heat loss is very large. Due to the large current load, the power loss caused by the thyristor is even worse, thereby reducing the conversion efficiency of the UPS power supply; in addition, since the thyristor may work with load for a long time, the rated current of the thyristor should be greater than the output rated current of the UPS power supply when selecting the thyristor. Therefore, in the actual application of the UPS power supply, the thyristor that meets the requirements is large in size and high in cost. Moreover, due to the large power consumption of the thyristor, a radiator and a fan need to be installed for heat dissipation. The space occupied by the radiator and the fan is large, and the line connection is complicated, resulting in a relatively complex overall process design of the UPS power supply.

[0013] The second switching method uses a conversion electromagnetic relay as the main switching switch for the bypass output mode and the inverter output mode, and the bidirectional thyristor is used to compensate for the instantaneous drop of the contact air travel when the conversion electromagnetic relay is switched. Since the bidirectional thyristor has a load-carrying characteristic, the instantaneous current within 20ms can reach 10 times the rated current. Therefore, during the switching instant between the bypass output mode and the inverter output mode (the air travel of the conversion electromagnetic relay is 5~15ms), a bidirectional thyristor with a smaller size and a rated current of less than half of the rated output current of the UPS power supply can be selected, which is conducive to cost optimization. The compensation time of the second switching method is short, the bidirectional thyristor basically does not heat up, and after the conversion electromagnetic relay is switched, the contact voltage drop of the conversion electromagnetic relay is basically negligible, so it has no effect on the overall efficiency of the UPS power supply. However, the second switching method has the following disadvantages:

[0014] Since the conversion type electromagnetic relay is a normally open monostable relay, the nominal rated current of the conversion type electromagnetic relay refers to the rated current carried by the contacts when they are working, and the switching current (make-on current, break-off current) that the contacts can withstand is usually less than half of the rated current; moreover, when the conversion type electromagnetic relay switches from the normally closed state to the normally open state, the jitter of the action contacts and the reversing contacts is small due to the energization of the electromagnet; and when the conversion type electromagnetic relay switches from the normally open state to the normally closed state, only the reset spring acts at this time, so when switching with large currents, the normally closed contacts are prone to jitter, sticking, and contact material transfer; therefore, within the effective life range, the maximum switching current that the normally open contacts and the normally closed contacts can withstand are inconsistent, and the maximum switching current of the normally open contacts is different. The current is usually 5 to 10 times that of the normally closed contact. Therefore, under the same full-load operating conditions, the maximum switching current can easily shorten the life of the normally closed contacts, cause material transfer, contact adhesion, and increased contact resistance, leading to abnormal consumption, heating and other fault phenomena, seriously affecting the life and reliability of the relay; in addition, when the second switching method is switched from the conversion type electromagnetic relay to the normally open contact, the coil of the conversion type electromagnetic relay must always have a voltage maintained, at least half of the rated voltage, which will cause the coil of the conversion type electromagnetic relay to heat up and lose, increase the power burden of the auxiliary working power supply, and reduce the reliability of the entire machine circuit. In addition, the long-term power-on maintenance of the coil of the conversion type electromagnetic relay is also very likely to generate electromagnetic interference, seriously affecting the stability of the overall circuit operation.

[0015] In view of the existence of the above problems, it is necessary to study an inverter bypass switching system for a UPS power supply, which can improve the stability and reliability of the UPS power supply when switching between inverter output mode and bypass output mode, and can reduce the overall volume of the UPS power supply and improve the overall efficiency of the UPS power supply. Summary of the invention

[0016] The object of the present invention is to provide an inverter bypass switching system for a UPS power supply, which can improve the stability and reliability of the UPS power supply when switching between an inverter output mode and a bypass output mode, and can reduce the overall volume of the UPS power supply and improve the overall efficiency of the UPS power supply.

[0017] In order to achieve the above object, the solution of the present invention is:

[0018] The invention discloses an inverter bypass switching system for a UPS power supply, comprising a main control module, a bypass module, an inverter module, an output module and a static conversion switch; the bypass module has a bypass live wire and a bypass neutral wire; the inverter module has an inverter live wire and an inverter neutral wire; the output module has an output live wire and an output neutral wire, and the output neutral wire is connected to the bypass neutral wire and the inverter neutral wire; the static conversion switch comprises a bidirectional thyristor and a conversion type magnetic latching relay; the first main electrode of the bidirectional thyristor and the reset contact of the conversion type magnetic latching relay are connected to the bypass live wire, the second main electrode of the bidirectional thyristor and the action contact of the conversion type magnetic latching relay are connected to the inverter live wire, and the middle contact of the conversion type magnetic latching relay is connected to the output live wire; the main control module is connected to the inverter module, the gate of the bidirectional thyristor, and the reset coil and the action coil of the conversion type magnetic latching relay respectively, the main control module controls the operation of the inverter module, controls the on and off of the bidirectional thyristor, and controls the conversion type magnetic latching relay to act and reset.

[0019] The inverter bypass switching system of a UPS power supply also includes a first logic control circuit, a second logic control circuit, a third logic control circuit and a relay drive circuit; the main control module is connected to two control ends of the relay drive circuit through the first logic control circuit and the second logic control circuit respectively, and the relay drive circuit is connected to the reset coil and the action coil of the conversion type magnetic latching relay; the main control module is also connected to the gate of the bidirectional thyristor through the third logic control circuit.

[0020] The first logic control circuit and the second logic control circuit are connected to two control terminals of the relay drive circuit respectively through the first isolation circuit and the second isolation circuit; the third logic control circuit is connected to the gate of the bidirectional thyristor through the third isolation circuit.

[0021] The inverter bypass switching system of a UPS power supply also includes an auxiliary power module and a power-on and power-off detection module. The auxiliary power module supplies power to the main control module, the first logic control circuit, the second logic control circuit, the third logic control circuit and the relay drive circuit; the detection end of the power-on and power-off detection module is connected to the auxiliary power module, and the output end of the power-on and power-off detection module is connected to the first logic control circuit; the power-on and power-off detection module is used to detect whether the auxiliary power module is powered on normally; when the power-on and power-off detection module detects that the auxiliary power module is powered on normally, the power-on and power-off detection module inputs a reset signal to the first logic control circuit, and the first logic control circuit drives the conversion type magnetic latching relay through the relay drive circuit to reset.

[0022] The inverter bypass switching system of a UPS power supply further comprises an auxiliary power module, a power-on and power-off detection module and an energy storage module. The auxiliary power module supplies power to the main control module, the first logic control circuit, the second logic control circuit, the third logic control circuit, the relay drive circuit and the energy storage module. The energy storage module is used to supply power to the first logic control circuit, the second logic control circuit, the third logic control circuit and the relay drive circuit when the auxiliary power module is at low voltage. The detection end of the power-on and power-off detection module is connected to the auxiliary power module, and the output end of the power-on and power-off detection module is connected to the first logic control circuit and the third logic control circuit. The power-on and power-off detection module is used to detect whether the auxiliary power module is at low voltage. When the power-on and power-off detection module detects that the auxiliary power module is at low voltage, the power-on and power-off detection module inputs a reset signal to the first logic control circuit and the third logic control circuit, and the first logic control circuit drives the conversion type magnetic latching relay to reset through the relay drive circuit, and the third logic control circuit controls the bidirectional thyristor to conduct during the reset process of the conversion type magnetic latching relay.

[0023] The energy storage module adopts a capacitor.

[0024] The power supply end of the energy storage module is connected to the output end of the auxiliary power supply module through a non-return diode, the positive pole of the non-return diode is connected to the output end of the auxiliary power supply module, and the negative pole of the non-return diode is connected to the power supply end of the energy storage module. The power supply end of the energy storage module is respectively connected to the power supply ends of the first logic control circuit, the second logic control circuit, the third logic control circuit and the relay drive circuit.

[0025] The inverter module includes an AC rectifier unit, an inverter unit and a battery unit. The battery unit is connected to the DC input side of the inverter unit and the DC output side of the AC rectifier unit. The DC input side of the inverter unit is connected to the DC output side of the AC rectifier unit. The AC output side of the inverter unit is connected to the inverter live wire and the inverter neutral wire.

[0026] The inverter bypass switching system of a UPS power supply further comprises a UPS detection module, and the UPS detection module is connected to the main control module.

[0027] The inverter bypass switching system of the UPS power supply also includes a phase-locked loop, and the main control module is connected to the bypass live wire through the phase-locked loop.

[0028] After adopting the above scheme, the present invention adopts a conversion type magnetic latching relay as the main switch for switching the UPS power supply between the inverter output mode and the bypass output mode. The conversion of the switch state of the conversion type magnetic latching relay is completed by triggering a pulse electrical signal of a certain width, and the conversion type magnetic latching relay maintains the reset state and the action state after the conversion completely relying on the action of the permanent magnetic steel. In this way, under the working condition of the rated current, the life of the action contact and the reset contact of the conversion type magnetic latching relay can be the same, and when the conversion type magnetic latching relay is switched, whether the reset contact or the action contact is working, it needs to be energized instantaneously, so the jitter of the reset contact or the action contact is smaller than that of the ordinary conversion type electromagnetic relay, and the probability of the reset contact or the action contact being stuck is higher than that of the ordinary conversion type electromagnetic relay. The ordinary conversion type electromagnetic relay is greatly reduced, thereby improving the stability and reliability of the UPS power supply when switching between the inverter output mode and the bypass output mode; in addition, the conversion type magnetic latching relay only needs to energize the action coil or the reset coil when switching. After the switching action is completed, the action coil or the reset coil of the conversion type magnetic latching relay does not need to be energized to maintain. The conversion type magnetic latching relay can achieve a good contact attraction force through the action of the internal permanent magnet. Therefore, the conversion type magnetic latching relay maintains low energy consumption when maintained in the action state or the reset state, reduces line electromagnetic interference, and can improve the overall efficiency of the UPS power supply. In addition, the conversion type magnetic latching relay generates little heat and does not require an additional heat sink, which helps to reduce the overall size of the UPS power supply.

[0029] In addition, the present invention adopts a bidirectional thyristor as a compensation switch for switching the UPS power supply between the inverter output mode and the bypass output mode. The bidirectional thyristor is turned on only at the moment (5-15ms) when the conversion magnetic latching relay is switched to compensate the AC output. Based on the characteristic that the bidirectional thyristor can withstand 10 times the rated current within 20ms, the present invention can select a bidirectional thyristor with a smaller size and a rated current of less than half of the rated output current of the UPS to meet the use requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a principle block diagram of the present invention.

[0031] Description of labels:

[0032] Main control module A,

[0033] Bypass module B, bypass live line L1, bypass neutral line N1,

[0034] Inverter module C, inverter live wire L2, inverter neutral wire N2, AC rectifier unit C1, inverter unit C2, battery unit C3,

[0035] Output module D, output live wire L3, output neutral wire N3,

[0036] Static transfer switch E, bidirectional thyristor E1, conversion type magnetic latching relay E2,

[0037] a first logic control circuit F, a first isolation circuit F1,

[0038] The second logic control circuit G, the second isolation circuit G1,

[0039] The third logic control circuit H, the third isolation circuit H1,

[0040] Relay drive circuit I,

[0041] Auxiliary power module J,

[0042] Power-on and power-off detection module K,

[0043] Energy storage module M,

[0044] The anti-reverse diode P,

[0045] UPS detection module Q,

[0046] Phase-locked loop R. DETAILED DESCRIPTION

[0047] In order to further explain the technical solution of the present invention, the present invention is described in detail below through specific embodiments.

[0048] like Figure 1As shown, the present invention discloses an inverter bypass switching system of a UPS power supply, which includes a main control module A, a bypass module B, an inverter module C, an output module D and a static transfer switch E; wherein the bypass module B has a bypass live wire L1 and a bypass neutral wire N1, and the bypass live wire L1 and the bypass neutral wire N1 are used to access the bypass AC power; the inverter module C has an inverter live wire L2 and an inverter neutral wire N2; the output module D has an output live wire L3 and an output neutral wire N3, and the output live wire L3 and the output neutral wire N3 are used to connect the load, and the output neutral wire N3 is connected to the bypass neutral wire N1 and the inverter neutral wire N2; the static transfer switch E includes a bidirectional thyristor E1 and a conversion type magnetic latching relay E2; the first main electrode of the bidirectional thyristor E1 and the reset contact of the conversion type magnetic latching relay E2 are connected to the bypass live wire L1, the second main electrode of the bidirectional thyristor E1 and the action contact of the conversion type magnetic latching relay E2 are connected to the inverter live wire L2, and the middle contact of the conversion type magnetic latching relay E2 is connected to the output live wire L3; the main control module A is connected to the inverter module C, the gate of the bidirectional thyristor E1, and the reset coil and the action coil of the conversion type magnetic latching relay E2 respectively, the main control module A controls the operation of the inverter module C, the main control module A controls the on and off of the bidirectional thyristor E1, and the main control module A also controls the conversion type magnetic latching relay E2 to act and reset. Among them, the conversion type magnetic latching relay E2 serves as the main switch for the UPS power supply to switch between the inverter output mode and the bypass output mode. When the conversion type magnetic latching relay E2 is in the reset state, so that the reset contact of the conversion type magnetic latching relay E2 is connected to the middle contact, the UPS power supply is in the bypass output mode, and the bypass module B provides AC power to the output module D; when the conversion type magnetic latching relay E2 is in the action state, so that the action contact of the conversion type magnetic latching relay E2 is connected to the middle contact, the UPS power supply is in the inverter output mode, and the inverter module C provides AC power to the output module D. The bidirectional thyristor E1 serves as a compensation switch for the UPS power supply to switch between the inverter output mode and the bypass output mode. When the main control module A controls the conversion magnetic latching relay E2 to switch the switch state (that is, when the UPS power supply switches between the inverter output mode and the bypass output mode), the main control module A controls the first main electrode and the second main electrode of the bidirectional thyristor E1 to be turned on during this switching process, thereby compensating for the instantaneous power failure of the output caused by the air travel of the contacts of the magnetic latching relay during switching, so that the output of the UPS power supply has zero interruption during the switching process.

[0049] The present invention adopts a conversion type magnetic latching relay E2 as the main switch for switching between the inverter output mode and the bypass output mode of the UPS power supply. The switching state of the conversion type magnetic latching relay E2 is completed by triggering a pulse electrical signal of a certain width, and the conversion type magnetic latching relay E2 maintains the reset state and the action state after the switching is completed, which completely depends on the effect of the permanent magnetic steel. In this way, under the working condition of the rated current, the life of the action contact and the reset contact of the conversion type magnetic latching relay E2 can be the same. When the conversion type magnetic latching relay E2 is switched, whether the reset contact or the action contact is working, it needs to be energized instantaneously. In this way, the jitter of the reset contact or the action contact is smaller than that of the ordinary conversion type electromagnetic relay, and the probability of the reset contact or the action contact being stuck is lower than that of the ordinary The conversion type electromagnetic relay is greatly reduced, thereby improving the stability and reliability of the UPS power supply when switching between the inverter output mode and the bypass output mode; in addition, the conversion type magnetic latching relay E2 only needs to energize the action coil or the reset coil when switching. After the switching action is completed, the action coil or the reset coil of the conversion type magnetic latching relay E2 does not need to be energized to maintain. The conversion type magnetic latching relay E2 can achieve a good contact attraction force through the action of the internal permanent magnet. Therefore, the conversion type magnetic latching relay E2 maintains low energy consumption when maintained in the action state or the reset state, reduces line electromagnetic interference, and can improve the overall efficiency of the UPS power supply. In addition, the conversion type magnetic latching relay E2 generates little heat and does not require an additional heat sink, which helps to reduce the overall size of the UPS power supply.

[0050] In addition, the present invention adopts a bidirectional thyristor E1 as a compensation switch for switching the UPS power supply between the inverter output mode and the bypass output mode. The bidirectional thyristor E1 is turned on only at the moment (5-15ms) when the conversion magnetic latching relay E2 is switched to compensate the AC output. Based on the characteristic that the bidirectional thyristor E1 can withstand 10 times the rated current within 20ms, the present invention can select a bidirectional thyristor E1 with a smaller size and a rated current of less than half of the rated output current of the UPS to meet the use requirements.

[0051] In an embodiment of the present invention, the inverter module C includes an AC rectifier unit C1, an inverter unit C2 and a battery unit C3, the battery unit C3 is connected to the DC input side of the inverter unit C2 and the DC output side of the AC rectifier unit C1, the DC input side of the inverter unit C2 is connected to the DC output side of the AC rectifier unit C1, and the AC output side of the inverter unit C2 is connected to the inverter live wire L2 and the inverter neutral wire N2. Among them, the AC input side of the AC rectifier unit C1 is used to access the external mains. When the inverter module C performs inversion, it can be: the mains is converted into DC power through the AC rectifier unit C1, and the DC power output by the AC rectifier unit C1 is then inverted into AC power by the inverter unit C2; when the inverter module C performs inversion, it can also be: the DC power output by the battery unit C3 is inverted into AC power by the inverter unit C2. The battery unit C3 can be charged through the AC rectifier unit C1.

[0052] In an embodiment of the present invention, an inverter bypass switching system of a UPS power supply of the present invention further includes a first logic control circuit F, a second logic control circuit G, a third logic control circuit H and a relay drive circuit I; the main control module A is connected to two control ends of the relay drive circuit I through the first logic control circuit F and the second logic control circuit G respectively, the relay drive circuit I is connected to the reset coil and the action coil of the conversion type magnetic latching relay E2, and the relay drive circuit I can control the reset coil and the action coil of the conversion type magnetic latching relay E2 to control the conversion type magnetic latching relay E2 to switch; the main control module A is also connected to the gate of the bidirectional thyristor E1 through the third logic control circuit H; the first logic control circuit F, the second logic control circuit G, and the third logic control circuit H can set and time the signals received by each (such as the signal output by the main control module A and the signal output by the power-on and power-off detection module K described below) to control the conversion type magnetic latching relay E2 and the bidirectional thyristor E1 accordingly. Among them, the first logic control circuit F and the second logic control circuit G are respectively connected to the two control ends of the relay drive circuit I through the first isolation circuit F1 and the second isolation circuit G1, and the third logic control circuit H is connected to the gate of the bidirectional thyristor E1 through the third isolation circuit H1. The first isolation circuit F1, the second isolation circuit G1 and the third isolation circuit H1 can play the role of "transmitting and amplifying the control signal, and electrically isolating the low-voltage side of the control signal from the high-voltage side of the main AC circuit". The first isolation circuit F1, the second isolation circuit G1 and the third isolation circuit H1 can adopt optocoupler isolation circuits.

[0053] In an embodiment of the present invention, an inverter bypass switching system of a UPS power supply of the present invention further includes an auxiliary power module J, a power-on and power-off detection module K and an energy storage module M. The auxiliary power module J supplies power to the main control module A, the first logic control circuit F, the second logic control circuit G, the third logic control circuit H, the relay drive circuit I and the energy storage module M; the energy storage module M is used to supply power to the first logic control circuit F, the second logic control circuit G, the third logic control circuit H and the relay drive circuit I when the auxiliary power module J is at low voltage; the detection end of the power-on and power-off detection module K is connected to the auxiliary power module J, and the output end of the power-on and power-off detection module K is connected to the first logic control circuit F and the third logic control circuit H. Among them, the power-on and power-off detection module K is used to detect the state of the auxiliary power module J, and the power-on and power-off detection module K has a power-on detection function (i.e., detecting whether the auxiliary power module J is normally powered on) and a power-off detection function (i.e., detecting whether the auxiliary power module J is at low voltage). When the power-on / off detection module K detects that the auxiliary power module J is powered on normally, the power-on / off detection module K inputs a reset signal to the first logic control circuit F, and the first logic control circuit F drives the conversion type magnetic latching relay E2 to reset through the relay driving circuit I (that is, the conversion type magnetic latching relay E2 is kept in the reset state); in this way, the conversion type magnetic latching relay E2 is automatically reset when the UPS power supply is powered on, eliminating the problem of unclear switch state of the conversion type magnetic latching relay E2 caused by transportation vibration and other reasons, ensuring that the UPS power supply puts the conversion type magnetic latching relay E2 in the reset state in advance before the inverter module C does not work, so that the UPS power supply is in the bypass output mode, ensuring safe use. In addition, when the power-on and power-off detection module K detects that the auxiliary power module J is under voltage, the UPS power supply cannot perform normal inversion work. The power-on and power-off detection module K inputs a reset signal to the first logic control circuit F and the third logic control circuit H. The first logic control circuit F drives the conversion type magnetic latching relay E2 to reset through the relay drive circuit I, so that the conversion type magnetic latching relay E2 switches to the reset state. At the same time, the third logic control circuit H controls the bidirectional thyristor E1 to conduct during the reset process of the conversion type magnetic latching relay E2 to compensate, thereby putting the UPS power supply in the bypass output mode to ensure reliable use.

[0054] In an embodiment of the present invention, the power supply end of the energy storage module M is connected to the output end of the auxiliary power supply module J through a non-return diode P, the positive electrode of the non-return diode P is connected to the output end of the auxiliary power supply module J, and the negative electrode of the non-return diode P is connected to the power supply end of the energy storage module M. The power supply end of the energy storage module M is respectively connected to the power supply ends of the first logic control circuit F, the second logic control circuit G, the third logic control circuit H and the relay drive circuit I; the non-return diode P can ensure that the auxiliary power supply module J can charge the energy storage module M, and prevent the energy storage module M from discharging to other circuits other than the first logic control circuit F, the second logic control circuit G, the third logic control circuit H and the relay drive circuit I, thereby reducing unnecessary energy consumption of the energy storage module M. The energy storage module M can specifically adopt a capacitor, which can store energy, and at the same time, the capacitor can also supply power to the first logic control circuit F, the second logic control circuit G, the third logic control circuit H and the relay drive circuit I for a short time, and the cost of the capacitor is low.

[0055] In an embodiment of the present invention, an inverter bypass switching system of a UPS power supply of the present invention further includes a phase-locked loop R, and the main control module A is connected to the bypass live wire L1 through the phase-locked loop R. The main control module A controls the AC power output by the bypass module B and the AC power output by the inverter module C to have the same frequency and phase through the phase-locked loop R, so as to avoid AC output disturbance when switching between the bypass output mode and the inverter output mode, thereby avoiding adverse effects on the load. The phase-locked loop R is a circuit module commonly used in UPS power supplies, and the specific structure of the phase-locked loop R will not be described in detail here.

[0056] In an embodiment of the present invention, an inverter bypass switching system of a UPS power supply of the present invention further includes a UPS detection module Q, which is connected to the main control module A; the UPS detection module Q is used to detect various states of the UPS power supply to switch the bypass output mode and the inverter output mode accordingly; the UPS detection module Q can detect: whether the battery unit C3 is inverter undervoltage, whether the output module D outputs overvoltage, whether the output module D outputs short circuit, whether the output module D outputs overload, whether the bypass AC power connected to the bypass module B is normal, and whether the AC power connected to the inverter module C is normal. The UPS detection module Q is a circuit module commonly used in UPS power supplies, and the specific structure of the UPS detection module Q will not be elaborated here.

[0057] To facilitate understanding of the present invention, the working mode of the present invention is described in detail below.

[0058] 1. When the UPS power supply is powered on for the first time, the auxiliary power supply module J starts to work and each component module supplies power; at this time, if the auxiliary power supply module J does not work properly, the UPS power supply cannot work normally; if the auxiliary power supply module J works normally, the auxiliary power supply module J charges the energy storage module M through the non-return diode P, and the power-on and power-off detection module K detects whether the auxiliary power supply module J is powered on normally; when the power-on and power-off detection module K detects that the auxiliary power supply module J is powered on normally, the power-on and power-off detection module K inputs a reset signal to the first logic control circuit F, and the first logic control circuit F drives the conversion type magnetic latching relay E2 to reset through the relay drive circuit I (that is, the conversion type magnetic latching relay E2 is kept in the reset state), so that the output mode of the UPS power supply is the bypass output mode.

[0059] 2. The steps to switch the UPS power supply output mode from bypass output mode to inverter output mode:

[0060] First, the UPS power supply follows the user's startup inverter instruction and resets the magnetic latching relay before the inverter module C performs the inverter output, so that the UPS power supply is in bypass output mode;

[0061] Then, the main control module A collects the mains power connected to the inverter module C through the UPS detection module Q to determine whether it is normal. If the mains power is normal, the main control module A controls the inverter module C to perform inversion, so that the mains power is converted into direct current through the AC rectifier unit C1, and the direct current output by the AC rectifier unit C1 is then inverted into alternating current by the inverter unit C2; and the main control module A phase-locks the alternating current output by the inverter module C with the alternating current output by the bypass module B through the phase-locked loop R;

[0062] Finally, after waiting for a preset time (generally 3s), the main control module A controls the conversion type magnetic latching relay E2 to switch from the reset state to the action state through the second logic circuit, and in the process of switching the conversion type magnetic latching relay E2 from the reset state to the action state, the main control module A controls the first main electrode and the second main electrode of the bidirectional thyristor E1 to be turned on during this switching process through the third logic circuit, thereby compensating for the instantaneous power failure of the output caused by the air travel of the contacts of the magnetic latching relay during switching.

[0063] 3. The steps to switch the UPS power supply output mode from inverter output mode to bypass output mode:

[0064] The main control module A controls the switching type magnetic latching relay E2 to switch from the action state to the reset state through the third logic circuit, and in the process of switching the switching type magnetic latching relay E2 from the action state to the reset state, the main control module A controls the first main electrode and the second main electrode of the bidirectional thyristor E1 to be turned on during this switching process through the third logic circuit.

[0065] 4. When the UPS power supply is in the inverter output mode, if the main control module A detects through the UPS detection module Q that the AC power connected to the inverter module C is off, then at this time, the DC power output by the battery unit C3 of the inverter module C is inverted into AC power output through the inverter unit C2; thereafter, if the main control module A detects through the UPS detection module Q that the battery unit C3 is at low voltage, the main control module A controls the output mode of the UPS power supply to switch from the inverter output mode to the bypass output mode, and the inverter module C stops working; thereafter, if the main control module A detects through the UPS detection module Q that the AC power connected to the inverter module C is on, the main control module A controls the output mode of the UPS power supply to switch from the bypass output mode to the inverter output mode.

[0066] 5. When the UPS power supply is in the inverter output mode, if the main control module A detects through the UPS detection module Q that the output module D is over-voltage, the output module D is short-circuited, or the output module D is overloaded, the main control module A controls the output mode of the UPS power supply to switch from the inverter output mode to the bypass output mode, and the inverter module C stops working.

[0067] 6. When the UPS power supply is in the inverter output mode, if the main control module A detects that the auxiliary power supply module J is low voltage through the power-on and power-off detection module K, the power-on and power-off detection module K inputs a reset signal to the first logic control circuit F and the third logic control circuit H, and the first logic control circuit F drives the conversion type magnetic latching relay E2 to reset through the relay drive circuit I, so that the conversion type magnetic latching relay E2 switches to the reset state. At the same time, the third logic control circuit H controls the bidirectional thyristor E1 to conduct during the reset process of the conversion type magnetic latching relay E2 to compensate, thereby making the UPS power supply in the bypass output mode.

[0068] It should be noted that the main control module A of the present invention may include a processor and a memory; the processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc. The memory may be an internal storage unit of a UPS power supply (such as a hard disk or memory of a UPS), or an external storage device of a UPS power supply (such as a plug-in hard disk equipped on a UPS, a smart memory card (SMC), a secure digital (SD) card, a flash card, etc.). The memory is used to store computer programs and other programs and data required for the operation of the UPS power supply. The memory may also be used to temporarily store data that has been output or is to be output.

[0069] It should also be noted that the technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example. In actual applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the UPS is divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated into a processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of analog hardware circuits or digital circuits, or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of mutual distinction, and are not used to limit the scope of protection of this application. As long as the technicians in the relevant field do not deviate from the essential functions of the present invention, they should be subject to the limitations of the invention and should be included in the scope of protection of the present invention. The specific working process of the units and modules in the above-mentioned device can refer to the corresponding process in the above-mentioned method embodiment, which will not be repeated here.

[0070] The above embodiments and drawings do not limit the product form and style of the present invention. Any appropriate changes or modifications made by ordinary technicians in the relevant technical field should be deemed to be within the patent scope of the present invention.

Claims

1. An inverter bypass switching system for a UPS power supply, characterized in that: It includes a main control module, a bypass module, an inverter module, an output module, a static transfer switch, a first logic control circuit, a second logic control circuit, a third logic control circuit, a relay drive circuit, an auxiliary power supply module and a power-on and power-off detection module; The bypass module has a bypass live wire and a bypass neutral wire; The inverter module has an inverter live wire and an inverter neutral wire; The output module has an output live wire and an output neutral wire, and the output neutral wire is connected to the bypass neutral wire and the inverter neutral wire; The static transfer switch includes a bidirectional thyristor and a conversion type magnetic latching relay; the first main electrode of the bidirectional thyristor and the reset contact of the conversion type magnetic latching relay are connected to the bypass live wire, the second main electrode of the bidirectional thyristor and the action contact of the conversion type magnetic latching relay are connected to the inverter live wire, and the middle contact of the conversion type magnetic latching relay is connected to the output live wire; The main control module is connected to the inverter module, the gate of the bidirectional thyristor, and the reset coil and the action coil of the conversion type magnetic latching relay respectively. The main control module controls the operation of the inverter module, controls the on and off of the bidirectional thyristor, and controls the conversion type magnetic latching relay to act and reset. The main control module is connected to two control terminals of the relay drive circuit through the first logic control circuit and the second logic control circuit respectively, and the relay drive circuit is connected to the reset coil and the action coil of the conversion type magnetic latching relay; the main control module is also connected to the gate of the bidirectional thyristor through the third logic control circuit; The auxiliary power supply module supplies power to the main control module, the first logic control circuit, the second logic control circuit, the third logic control circuit and the relay drive circuit; The detection end of the power-on and power-off detection module is connected to the auxiliary power supply module, and the output end of the power-on and power-off detection module is connected to the first logic control circuit; The power-on and power-off detection module is used to detect whether the auxiliary power supply module is powered on normally; when the power-on and power-off detection module detects that the auxiliary power supply module is powered on normally, the power-on and power-off detection module inputs a reset signal to the first logic control circuit, and the first logic control circuit drives the conversion type magnetic latching relay through the relay drive circuit to reset.

2. The inverter bypass switching system of a UPS power supply according to claim 1, characterized in that: The first logic control circuit and the second logic control circuit are respectively connected to two control terminals of the relay drive circuit through the first isolation circuit and the second isolation circuit; The third logic control circuit is connected to the gate of the bidirectional thyristor through the third isolation circuit.

3. The inverter bypass switching system of a UPS power supply according to claim 1, characterized in that: It also includes an energy storage module, and the auxiliary power module also supplies power to the energy storage module; the energy storage module is used to supply power to the first logic control circuit, the second logic control circuit, the third logic control circuit and the relay drive circuit when the auxiliary power module is at low voltage; The power-on and power-off detection module is also used to detect whether the auxiliary power supply module is under voltage; when the power-on and power-off detection module detects that the auxiliary power supply module is under voltage, the power-on and power-off detection module inputs a reset signal to the first logic control circuit and the third logic control circuit, and the first logic control circuit drives the conversion type magnetic latching relay to reset through the relay drive circuit, and at the same time, the third logic control circuit controls the bidirectional thyristor to turn on during the reset process of the conversion type magnetic latching relay.

4. The inverter bypass switching system of a UPS power supply as claimed in claim 3, characterized in that: The energy storage module adopts a capacitor.

5. The inverter bypass switching system of a UPS power supply as claimed in claim 3, characterized in that: The power supply end of the energy storage module is connected to the output end of the auxiliary power supply module through a non-return diode, the positive pole of the non-return diode is connected to the output end of the auxiliary power supply module, and the negative pole of the non-return diode is connected to the power supply end of the energy storage module. The power supply end of the energy storage module is respectively connected to the power supply ends of the first logic control circuit, the second logic control circuit, the third logic control circuit and the relay drive circuit.

6. The inverter bypass switching system of a UPS power supply according to claim 1, characterized in that: The inverter module includes an AC rectifier unit, an inverter unit and a battery unit. The battery unit is connected to the DC input side of the inverter unit and the DC output side of the AC rectifier unit. The DC input side of the inverter unit is connected to the DC output side of the AC rectifier unit. The AC output side of the inverter unit is connected to the inverter live wire and the inverter neutral wire.

7. The inverter bypass switching system of a UPS power supply according to claim 1, characterized in that: It also includes a UPS detection module, which is connected to the main control module.

8. The inverter bypass switching system of a UPS power supply according to claim 1, characterized in that: It also includes a phase-locked loop, through which the main control module is connected to the bypass live wire.

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