Uninterruptible power supply

Abstract

The utility model provides an uninterruptible power supply. The uninterruptible power supply comprises a Hall sensor, a rectifier, an inverter and a bypass module, the first end of the Hall sensor is connected with an alternating-current power grid, the second end of the Hall sensor is connected with the input end of the rectifier and the first end of the bypass module, the output end of the rectifier is connected with the input end of the inverter, and the output end of the inverter and the second end of the bypass module are connected with a load; the Hall sensor is used for collecting a first sampling current flowing from the bypass module to the alternating current power grid when the uninterruptible power supply provides active power for the load through the bypass module and provides reactive power for the load through the inverter, and is also used for providing active power for the load through the rectifier and the inverter when the uninterruptible power supply provides reactive power for the load through the rectifier and the inverter; and when reactive power is provided for the load through the inverter, a second sampling current input into the rectifier is collected. According to the invention, circuit devices can be saved, the circuit structure is simple, and the applicability is high.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electronic power, and particularly relates to an uninterruptible power supply. BACKGROUND

[0002] An uninterruptible power supply (UPS) is a power supply containing an energy storage device, which is mainly used to provide uninterrupted power supply for devices with high requirements for power supply stability. The UPS usually includes a rectifier (REC), an inverter (INV), a direct-current power supply and a bypass module. The UPS can process the alternating current energy input by the alternating current grid and supply power to the load. Among them, the UPS can filter and transform the alternating current energy input by the alternating current grid to provide pure and high-stability power to the load. It can be understood that the UPS can supply power to the load through the main path branch of the rectifier and the inverter, and can also supply power to the load through the bypass path branch of the bypass module. When the alternating current grid output is interrupted or power failure occurs, the UPS can also supply the direct current energy stored in the direct current power supply to the load to maintain normal operation of the load and protect the load from damage.

[0003] In the prior art, because the UPS can switch different branches to supply power to the load according to the voltage or current of the alternating current energy input by the alternating current grid or the demand of the load, in this process, multiple current sensors are often needed to adjust the output of the rectifier or the inverter and other devices through the size of the current flowing through the load through different branches, thus leading to the problems of multiple circuit devices, complex circuit structure, poor stability and poor adaptability of the UPS in the prior art. Practical new type content

[0004] The present application provides an uninterruptible power supply, which can realize current collection when the uninterruptible power supply provides active power to the load through different paths by multiplexing the Hall sensor, can save the circuit devices included in the uninterruptible power supply, can reduce the complexity of the circuit structure of the uninterruptible power supply, can improve the circuit stability of the uninterruptible power supply, and has high adaptability.

[0005] The application provides an uninterrupted power supply, which comprises a Hall sensor, a rectifier, an inverter and a bypass module, a first end of the Hall sensor is connected with an AC power grid, a second end of the Hall sensor is connected with an input end of the rectifier and a first end of the bypass module, an output end of the rectifier is connected with an input end of the inverter, and an output end of the inverter and a second end of the bypass module are connected with a load. The Hall sensor is used to collect a first sampling current flowing from the bypass module to the AC power grid when the uninterrupted power supply provides active power to the load through the bypass module and provides reactive power to the load through the inverter, and the first sampling current is used for driving control of the inverter. The Hall sensor is also used to collect a second sampling current input to the rectifier when the uninterrupted power supply provides active power to the load through the rectifier and the inverter and provides reactive power to the load through the inverter, and the second sampling current is used for driving control of the rectifier. In the application, the same Hall sensor can be used to collect the first sampling current for driving control of the inverter when the uninterrupted power supply provides active power to the load through the bypass module and provides reactive power to the load through the inverter, and can also be used to collect the second sampling current for driving control of the inverter when the uninterrupted power supply provides active power to the load through the rectifier and the inverter and provides reactive power to the load through the inverter. The current collection when the uninterrupted power supply provides active power to the load through different paths can be realized by multiplexing the Hall sensor, the circuit devices included in the uninterrupted power supply can be saved, the complexity of the circuit structure of the uninterrupted power supply can be reduced, the circuit stability of the uninterrupted power supply can be improved, and the applicability is high.

[0006] In a possible implementation, the uninterrupted power supply further comprises a control module, which is used to control the bypass module to provide active power to the load and control the inverter to provide reactive power to the load when the input of the AC power grid is normal, acquire the first sampling current from the Hall sensor, and adjust the DC component output by the inverter based on the first sampling current to realize driving control of the inverter. In the application, the control module can control the bypass module and the inverter to work to provide active power to the load through the bypass module and provide reactive power to the load through the inverter, and can also realize driving control of the inverter based on the first sampling current acquired from the Hall sensor, so that the DC component output by the inverter can be effectively inhibited, the power supply quality of the load can be improved, and the quality of the AC power grid can be improved.

[0007] In a possible implementation, the control module is further configured to, when detecting that the input of the AC power grid is abnormal, control the bypass module to be disconnected, control the rectifier and the inverter to provide active power to the load, and control the inverter to provide reactive power to the load, and obtain a second sampling current from the Hall sensor, and adjust the input current of the rectifier based on the second sampling current to achieve drive control of the rectifier. In this application, the control module can control the rectifier and the inverter to work to provide active power to the load through the rectifier and the inverter and provide reactive power to the load through the inverter, and can also achieve drive control of the rectifier based on the second sampling current obtained from the Hall sensor, thereby improving the waveform of the input current of the rectifier and improving the reliability of power supply.

[0008] In a possible implementation, the uninterruptible power supply further includes a current transformer; a first end of the current transformer is connected to an output end of the inverter, and a second end of the current transformer is connected to the load. The current transformer is configured to collect the output current of the inverter when the uninterruptible power supply provides active power to the load through the bypass module and provides reactive power to the load through the inverter. At this time, the control module is configured to obtain the output current from the current transformer and perform harmonic compensation on the load based on the output current and the first sampling current. In this application, the current transformer can collect the output current of the inverter in real time, the control module can obtain the output current of the inverter from the current transformer in real time, and the load can be compensated for harmonics according to the output current of the inverter, thereby ensuring the stability and safety of the operation of the uninterruptible power supply and improving the applicability.

[0009] In a possible implementation, the control module includes a direct current component adjustment unit, a harmonic compensation unit, and a modulation signal generation unit. The direct current component adjustment unit is configured to output a direct current suppression signal to the modulation signal generation unit based on the first sampling current when detecting that the first sampling current has a direct current component; the direct current suppression signal is used to suppress the output direct current of the inverter. The harmonic compensation unit is configured to output a harmonic compensation signal to the modulation signal generation unit based on the output current and the first sampling current; the harmonic compensation signal is used to compensate for harmonics of the load. The modulation signal generation unit is configured to generate a target modulation signal based on the direct current suppression signal and the harmonic compensation signal; the target modulation signal is used to suppress the direct current component of the output of the inverter and compensate for harmonics of the load. In this application, when the first sampling current has a direct current component, the target modulation signal used to drive the inverter to work can be generated through the joint action of the direct current component adjustment unit, the harmonic compensation unit, and the modulation signal generation unit, which can effectively suppress the direct current component of the output of the inverter and compensate for harmonics of the load, thereby canceling the harmonic component in the load current, achieving high power quality power supply to the load, and improving the quality of the AC power grid and reducing power loss.

[0010] In a possible implementation, the bypass module comprises a static input switch. The static input switch is configured to control the bypass module to turn on or turn off the connection between the AC power grid and the load. In this application, the static input switch can be used to control the bypass module to turn on, so that the UPS can quickly switch between the power supply through the bypass branch and the power supply through the main branch, the conversion time is extremely short, the response speed is fast, and the continuous power supply output of the UPS to the load can be ensured.

[0011] In a possible implementation, the UPS further comprises a filter module, which is connected between the AC power grid and the rectifier. The filter module is configured to filter the AC power input from the AC power grid. In this application, the filter module filters the AC power input from the AC power grid, so that the harmonic interference of the AC power grid can be filtered out to provide pure power to the load, thereby improving the reliability of the circuit.

[0012] In a possible implementation, the UPS further comprises a DC power supply. When the UPS provides active power to the load through the bypass module and provides reactive power to the load through the inverter, the DC power supply supplies power to the inverter, so that the stable output of the UPS can be ensured, and the reliability of the UPS is enhanced.

[0013] In a possible implementation, the DC power supply comprises a battery and a DC converter. The output end of the battery is connected to the input end of the DC converter, and the output end of the DC converter is connected to the output end of the rectifier and the input end of the inverter. The DC converter is configured to convert the power provided by the battery into target power to supply power to the inverter when the UPS provides active power to the load through the bypass module and provides reactive power to the load through the inverter. The energy of the target power is based on the demand of the inverter.

[0014] In a possible implementation, the rectifier is further configured to obtain AC power from the AC power grid and convert the AC power into DC power through the DC converter to charge the battery when the rectifier provides active power to the load. The stability of the battery can be ensured, so that the power supply stability of the UPS can be improved, and the structure is simple and adaptable. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 FIG. 1 is a structural schematic diagram of a UPS provided by the present application;

[0016] Figure 2 FIG. 2 is another structural schematic diagram of the UPS provided by the present application;

[0017] Figure 3 FIG. 3 is another structural schematic diagram of the UPS provided by the present application;

[0018] Figure 4is a schematic diagram of power flow of the UPS provided by the present application working in the main path mode;

[0019] Figure 5 is a schematic diagram of power flow of the UPS provided by the present application working in the bypass mode;

[0020] Figure 6 is a schematic diagram of power flow of the UPS provided by the present application working in the VI mode;

[0021] Figure 7 is another schematic diagram of the UPS provided by the present application;

[0022] Figure 8 is a schematic diagram of the control module provided by the present application;

[0023] Figure 9 is another schematic diagram of the UPS provided by the present application. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application, and are not used to limit the present application.

[0025] Referring to Figure 1 , Figure 1 is a schematic diagram of the UPS provided by the present application. As shown in Figure 1As shown, the UPS includes a rectifier, an inverter, a DC power supply and a bypass module. The input end of the rectifier and the first end of the bypass module are connected to an AC power grid, the output end of the rectifier is connected to the input end of the inverter and the DC power supply, and the output end of the inverter and the second end of the bypass module are connected to a load. Among them, the main path branch of the UPS includes the rectifier and the inverter, and the rectifier can convert the AC power input by the AC power grid into DC power, and then the inverter converts the DC power into AC output to the load. The bypass branch of the UPS includes the bypass module, and the UPS can supply power to the load through the bypass module. Correspondingly, the common working modes of the UPS include a main path mode and a bypass mode. In the main path mode, the UPS can supply power to the load through the main path branch, that is, through the joint action of the rectifier and the inverter to supply power to the load, and when the inverter fails or the inverter is overloaded, it can be switched from the main path mode to the bypass mode, that is, through the bypass module to supply power to the load. It should be understood that the cooperation of the main path mode and the bypass mode can ensure uninterrupted output of electric energy to provide continuous and uninterrupted electric energy to the load. However, the system efficiency of the UPS in this mode is low and the loss is high. In order to improve the system efficiency of the UPS, a voltage independent (VI) mode is introduced, and the UPS works in the bypass mode first, at this time, the inverter can also perform harmonic and reactive power compensation on the load. When the input of the AC power grid is abnormal, the UPS switches to the main path mode.

[0026] In order to ensure the power supply quality of the UPS to the load in different working modes, it is often necessary to collect the current flowing through different branches to adjust the output of the rectifier or the inverter and other devices. Referring to Figure 2 , Figure 2 is another structural schematic diagram of the UPS provided by the present application. As shown in Figure 2 , hall sensors (HCT) such as HCT1 and HCT2 can be arranged at the input end of the rectifier and the output end of the inverter, and current transformers (CT) such as CT1 can also be arranged at the load side.

[0027] When the UPS works in the main path mode, the input current of the rectifier can be collected through the HCT1 to control the input waveform of the rectifier to be the same as the voltage waveform of the AC power grid based on the input current of the rectifier, so that a better power factor can be obtained. The CT1 can be used to sample the output current of the UPS working in the main path mode or the bypass mode, and based on the current collected by the CT1, abnormalities existing in the output current of the UPS can be found in time, and then the output current of the UPS can be adjusted to meet the power supply demand of the load.

[0028] In some possible embodiments, when the UPS works in the VI mode, since the CT1 cannot collect the direct current component on the inverter output current, not only the input current of the rectifier needs to be collected through the HCT1, but also the direct current component of the inverter output current needs to be collected through the HCT2, so as to suppress the output direct current component of the inverter, and further suppress the output direct current component of the inverter to achieve compensation for the load. It should be understood that the additional HCT2 causes the circuit devices of the UPS to be more, the circuit structure to be more complex, the stability to be poor, and the cost to be increased, and is not conducive to miniaturization.

[0029] The application relates to an uninterruptible power supply (UPS), which realizes current collection when the UPS provides active power to a load through different paths by multiplexing Hall sensors, saves circuit devices included in the UPS, reduces the complexity of a circuit structure of the UPS, improves the circuit stability of the UPS, and has high applicability.

[0030] Referring to Figure 3 , Figure 3 is another structural schematic diagram of the UPS provided by the application. As shown in Figure 3 , the UPS includes an HCT1, a rectifier, an inverter, and a bypass module. A first end of the HCT1 is connected to an AC power grid, a second end of the HCT1 is connected to an input end of the rectifier and a first end of the bypass module, an output end of the rectifier is connected to an input end of the inverter, and an output end of the inverter and a second end of the bypass module are connected to a load. The AC power grid can be a mains power, that is, a power frequency alternating current, for example, a single-phase alternating current or a three-phase 380V, 50 hertz (HZ) alternating current. The three phases of the three-phase alternating current are respectively referred to as an A phase, a B phase, and a C phase. For convenience of description, a single-phase alternating current is taken as an example in the following detailed description. The load can consume power supplied from the AC power grid. Exemplarily, the load can be electrical equipment in a factory, and the load can also be a server, a processor, a memory, and the like in a data center. The application is not limited thereto.

[0031] The HCT1 can collect a first sampling current flowing from the bypass module to the AC power grid when the UPS provides active power to the load through the bypass module and provides reactive power to the load through the inverter, and the first sampling current is used for driving control of the inverter. The HCT1 can also collect a second sampling current input to the rectifier when the UPS provides active power to the load through the rectifier and the inverter and provides reactive power to the load through the inverter, and the second sampling current is used for driving control of the rectifier.

[0032] Referring to Figure 4 , Figure 4 is a power flow schematic diagram of the UPS working in the main path mode provided by the application. As shown in Figure 4As shown, the rectifier can convert the alternating current energy input by the alternating current power grid into direct current energy, and the inverter can convert the direct current energy into alternating current output to the load, so as to realize that when the UPS works in the main path mode, the alternating current power grid supplies power to the load through the main path branch, that is, the UPS supplies active power to the load through the rectifier and the inverter, and supplies reactive power to the load through the inverter.

[0033] As shown in Figure 3 , the UPS can further include a direct current power supply, which can include a battery and a direct current converter, the output end of the battery being connected to the input end of the direct current converter, and the output end of the direct current converter (direct current to direct current, DC-DC converter) being connected to the output end of the rectifier and the input end of the inverter. Among them, the direct current converter can adopt a bidirectional boost / buck topology, and when the UPS works in the main path mode, the direct current converter can perform direct current conversion processing on the direct current energy output by the rectifier and output to the battery to charge the battery. Exemplarily, the battery can include a lithium iron phosphate battery (LiFePO4, LPF), a valve regulated lead acid battery (VRLA) and the like.

[0034] In some possible embodiments, when the UPS works in the main path mode, that is, when active power is supplied to the load through the rectifier and the inverter, and reactive power is supplied to the load through the inverter, at this time, the rectifier can obtain alternating current energy from the alternating current power grid and convert it into direct current through the direct current converter to charge the battery. Specifically, the rectifier can obtain active power from the alternating current power grid, and the direct current converter can perform direct current conversion on the direct current energy output by the rectifier to charge the battery, so as to ensure the stability of the battery capacity, thereby improving the power supply stability of the UPS, and the structure is simple and has strong adaptability. Optionally, when the alternating current power grid output is interrupted or power failure occurs, the UPS can also supply the direct current energy stored in the battery to the load through the direct current inverter, so as to maintain the normal work of the load and protect the load from being damaged.

[0035] Referring to Figure 5 , Figure 5 is a schematic diagram of power flow when the UPS works in the bypass mode. As shown in Figure 5 , when the inverter fails or is overloaded, the UPS can switch from the main path mode to the bypass mode, and the alternating current power grid can supply power to the load through the bypass branch, that is, through the bypass module. Among them, the bypass module can be used to control the connection or disconnection of the alternating current power grid and the load.

[0036] In some possible embodiments, the bypass module can comprise a static input switch. The static input switch can be connected in series between the AC power supply and the load, and can be used to control the bypass module to turn on or turn off the connection between the AC power grid and the load. Optionally, the bypass module can further comprise a bypass input switch arranged between the AC power grid and the static switch. In the preferred embodiment of the present application, the bypass input switch can be a bidirectional power switching device, for example, a circuit breaker, a contactor or a power tube. It can be understood that the static input switch can be used to control the bypass module to turn on, so that the UPS can quickly switch between the power supply through the bypass branch and the power supply through the main branch, the conversion time is extremely short, the response speed is fast, and the continuous power output of the UPS to the load can be ensured.

[0037] It can be seen that the cooperation of the UPS through the main branch mode and the bypass mode can ensure uninterrupted output of electric energy. In order to improve the system efficiency of the UPS, the VI mode is introduced, and the power flow diagram when the UPS works in the VI mode can be seen from Figure 6 When the UPS works in the VI mode, the UPS will preferentially supply power to the load through the bypass branch. At this time, the UPS supplies active power to the load through the bypass module, and supplies reactive power to the load through the inverter.

[0038] In some possible embodiments, as shown in Figure 6 When the DC power supply supplies power to the inverter when the UPS supplies active power to the load through the bypass module and supplies reactive power to the load through the inverter, the DC converter can convert the electric energy provided by the battery into target electric energy to supply power to the inverter, and the energy size of the target electric energy is based on the demand of the inverter. Among them, the DC converter can perform DC conversion processing on the electric energy provided by the battery to step up or step down the electric energy provided by the battery, so that the target electric energy obtained after stepping up or stepping down meets the working demand of the inverter, and the stable output of the UPS can be ensured, and the reliability of the UPS is enhanced.

[0039] It should be understood that the system efficiency of the UPS in the VI mode is higher than that of the UPS in the main branch mode, and when the UPS works in the VI mode, not only can the inverter supply reactive power to the load, but also can compensate the harmonics of the load through the inverter, so that the input current of the UPS meets the grid specification. When the mains is abnormal, the UPS can switch from the VI mode to the main branch mode to work, so as to ensure the continuous power output of the UPS to the load.

[0040] The rectifier and the inverter can be any known rectifier and inverter. Preferably, the rectifier and the inverter can also be bidirectional converters, such as two-level bidirectional converters, three-level bidirectional converters or multi-level bidirectional converters, where the multi-level bidirectional converter refers to a four-level or above bidirectional converter. The rectifier and the inverter each include a plurality of switching elements, so that the AC power input from the AC grid can be converted from AC to DC by controlling the on-off of different switching elements through pulse width modulation signals, and the power factor can be corrected (PFC) to obtain a high power factor and a low total harmonic current distortion (THDi), thereby improving the harmonic current on the AC grid side, and having the advantages of high power supply reliability and good input current waveform.

[0041] Please also refer to Figure 6 When the UPS works in the VI mode and the input of the AC grid is normal, that is, the UPS provides active power to the load through the bypass module and provides reactive power to the load through the inverter, if there is a bias voltage on the output voltage of the inverter, a DC component will be generated on the output current of the inverter, and the DC component will flow from the bypass module to the AC grid. It can be understood that the DC component injected into the AC grid will cause corrosion of the grid cable, generate a high primary current peak, and even burn out the input fuse, cause power failure, and even increase the harmonic component, so it is necessary to control the DC component on the output current of the inverter to ensure the power supply quality.

[0042] As shown in Figure 6 Since the HCT1 is arranged before the connection point of the bypass module and the rectifier, when the UPS works in the VI mode, the HCT1 can collect the input current of the bypass module, that is, the first sampling current. Since the DC component on the output current of the inverter will flow from the bypass module to the AC grid, the first sampling current collected by the HCT1 contains the DC component on the output current of the inverter. According to Kirchhoff's current law (KCL), the DC component of the first sampling current is equal to the difference between the DC component of the inverter output current and the DC component of the load current, and the DC component of the load current is relatively small and can be ignored. At this time, it can be determined that the DC component in the first sampling current is the DC component generated on the output current of the inverter, and the first sampling current can be filtered to obtain the DC component flowing from the bypass module to the AC grid. In addition, the DC component in the first sampling current can be controlled, and the drive of the inverter can be controlled to make the DC component on the output current of the inverter within a reasonable range, thereby improving the power supply quality of the load and protecting the AC grid from pollution.

[0043] When the UPS works in the VI mode and the input of the AC power grid is abnormal, the bypass module can be controlled to disconnect the AC power grid from the load, so that the UPS switches to the main path mode to work, that is, the UPS provides active power to the load through the rectifier and the inverter, and provides reactive power to the load through the inverter. At this time, as shown in FIG. 1, the HCT1 can collect the second sampling current of the input rectifier, that is, the input current of the rectifier. The input current of the rectifier can be used for driving control of the rectifier, for example, the waveform quality and unit power factor of the input current of the rectifier are controlled through the current inner loop, so that the input current of the rectifier meets the power supply demand of the load. The specific implementation manner is known to those skilled in the art, and will not be described in detail here. Figure 4

[0044] It can be understood that the UPS provided by the application can realize current collection when providing active power to the load through different paths by using only one HCT1. When the UPS works in the VI mode, that is, the UPS provides active power to the load through the bypass module and provides reactive power to the load through the inverter, the HCT1 can collect the first sampling current for driving control of the inverter. When the UPS works in the main path mode, that is, the UPS provides active power to the load through the rectifier and the inverter, and provides reactive power to the load through the inverter, the HCT1 can collect the second sampling current for driving control of the inverter. The circuit devices included in the UPS are saved, the hardware cost and the occupied space are reduced, the complexity of the circuit structure of the UPS is reduced, the circuit stability is improved, and the applicability is high.

[0045] Referring to Figure 7 , Figure 7 is another structural schematic diagram of the UPS provided by the application. As shown in FIG. 2, the UPS further includes a control module. The control module can control the bypass module to provide active power to the load and control the inverter to provide reactive power to the load when the input of the AC power grid is normal, and obtain the first sampling current from the HCT1, and adjust the direct current component output by the inverter based on the first sampling current to realize driving control of the inverter. Figure 7

[0046] ​​In some possible embodiments, the control module can collect operating parameters of the AC power input from the AC power grid, such as voltage and frequency of the AC power input from the AC power grid, and can also collect operating parameters of the UPS and the load, such as voltage, current, battery capacity, charging and discharging state, working mode, and load rate of the load, and the like. The voltage can be the input voltage or the output voltage of each circuit, for example, the input voltage or the output voltage of the rectifier. The working mode includes the main path mode, the bypass mode, and the VI mode. When the load is an air conditioning device, the operating parameters can include the working state of the compressor, the fan state, the heater state, the humidifier state, the air speed, the temperature, and / or the humidity set by the air conditioning device, and the like. When the load is a core device, the operating parameters can include the power-on or power-off of the core device, and the like. Optionally, when the DC power source includes a battery and a DC converter, the control module can also collect the battery capacity, the charging and discharging state, and the like. It should be understood that the operating parameters collected by the control module can be determined according to the actual application scenario, which is not limited herein. The control module can also control the working state of the UPS according to the operating parameters, for example, the control module can issue control commands to the circuits of each part of the UPS, so that each part of the circuit in the system operates according to the corresponding control command.

[0047] In some possible embodiments, the control module can set the working mode of the UPS according to the operating parameters. For example, if the control module detects that the voltage of the AC power input from the AC power grid is within a preset voltage range, and the load rate is within a preset load rate range, the control module can control the UPS to work in the VI mode, that is, the control module controls the bypass module to connect the AC power grid and the load, so as to control the bypass module to provide active power to the load, and controls the inverter to provide reactive power to the load. The preset voltage range can be determined according to the voltage specified by the UPS. For example, if the voltage specified by the UPS is 220V, the preset voltage range is ±10%, and the preset load rate range is greater than 10%, when the voltage of the AC power input from the AC power grid is between 210V and 230V, and the load rate is greater than 10%, the control module can control the UPS to work in the VI mode. Otherwise, the control module can control the UPS to work in the main path mode, that is, the control module controls the rectifier and the inverter to provide active power to the load and controls the inverter to provide reactive power to the load.

[0048] Optionally, the control module can also detect the capacity of the inverter (such as overload, reactive power, and active power). When the control module detects that the inverter is overloaded or fails, the control module can control the UPS to work in the bypass mode, that is, the control module controls the bypass module to connect the AC power grid and the load, so as to supply power to the load through the bypass module. For example, Figure 6As shown, when the working mode of the UPS is the VI mode, the control module can further obtain the first sampling current from the HCT1, and adjust the DC component of the output of the inverter based on the first sampling current to achieve the drive control of the inverter.

[0049] It can be understood that the control module can control the bypass module and the inverter to work to provide the active power to the load through the bypass module and provide the reactive power to the load through the inverter, and can also achieve the drive control of the inverter based on the first sampling current obtained from the HCT1, so as to effectively suppress the DC component of the output of the inverter, improve the power supply quality of the load, and improve the quality of the AC power grid.

[0050] In some possible embodiments, when the control module detects that the input of the AC power grid is abnormal, the control module can control the bypass module to disconnect the AC power grid from the load, control the rectifier and the inverter to provide the active power to the load and control the inverter to provide the reactive power to the load, and obtain the second sampling current from the HCT1, and adjust the input current of the rectifier based on the second sampling current to achieve the drive control of the rectifier. Wherein, the control module can detect whether the input of the AC power grid is abnormal, for example, when the control module detects that the voltage of the AC power energy input by the AC power grid is not within a preset voltage range and / or the frequency is not within a preset frequency range, it can be determined that the input of the AC power grid is abnormal. Wherein, the preset frequency range can be determined according to the frequency specified by the UPS. For example, if the voltage specified by the UPS is 220V and the frequency is 50Hz, the preset voltage range is ±10%, and the preset frequency range is ±2Hz, when the voltage of the AC power energy input by the AC power grid is not between 210V and 230V and / or the frequency of the AC power energy input by the AC power grid is not between 48Hz and 52Hz, it can be determined that the input of the AC power grid is abnormal. At this time, the control module can control the UPS to work in the main path mode, that is, control the rectifier and the inverter to provide the active power to the load, and control the inverter to provide the reactive power to the load. For example, Figure 4 As shown, when the working mode of the UPS is the main path mode, the control module can further obtain the second sampling current from the HCT1, and adjust the input current of the rectifier based on the second sampling current to achieve the drive control of the rectifier.

[0051] It can be understood that the control module can control the rectifier and the inverter to work to provide the active power to the load through the rectifier and the inverter and provide the reactive power to the load through the inverter, and can also achieve the drive control of the rectifier based on the second sampling current obtained from the HCT1, so as to achieve the improvement of the waveform of the input current of the rectifier, and further improve the power supply reliability.

[0052] In another embodiment, the skilled in the art can preset the priority of the working mode, for example, if the priority of the VI mode is higher than that of the main path mode, the UPS preferentially works in the VI mode, and when the VI mode appears abnormal, such as abnormal mains, the UPS works in the main path mode. It can be seen that the skilled in the art can select the working mode of the UPS according to the specific circuit to meet the power supply demand of the load.

[0053] In some possible implementations, as shown in Figure 2 the UPS further includes a CT2, a first end of the CT2 is connected to the output end of the inverter, and a second end of the CT2 is connected to the load. Wherein, the CT2 can collect the output current of the inverter when the UPS provides active power to the load through the bypass module and provides reactive power to the load through the inverter. At this time, the control module can obtain the output current from the CT2, and perform harmonic compensation on the load based on the output current and the first sampling current. It can be understood that the CT2 can collect the output current of the inverter in real time, the control module can obtain the output current of the inverter from the CT2 in real time, and perform harmonic compensation on the load according to the output current of the inverter, thereby ensuring the working stability and safety of the UPS, and having strong applicability.

[0054] In some possible implementations, referring to Figure 8 , Figure 8 is a structural schematic diagram of the control module provided by the present application. As shown in Figure 8 the control module includes a direct current component adjusting unit, a harmonic compensation unit and a modulation signal generating unit. Wherein, the direct current component adjusting unit is configured to output a direct current suppression signal to the modulation signal generating unit based on the first sampling current when it is detected that the first sampling current has a direct current component; the direct current suppression signal is used to suppress the output direct current of the inverter. The harmonic compensation unit is configured to output a harmonic compensation signal to the modulation signal generating unit based on the output current and the first sampling current; the harmonic compensation signal is used to perform harmonic compensation on the load. The modulation signal generating unit is configured to generate a target modulation signal based on the direct current suppression signal and the harmonic compensation signal; the target modulation signal is used to suppress the direct current component of the output of the inverter and perform harmonic compensation on the load.

[0055] In a specific implementation, when the UPS provides active power to the load through the bypass module and provides reactive power to the load through the inverter, i.e., the UPS works in VI mode, the DC component adjusting unit can receive the first sampled current and filter the first sampled current to obtain a DC component of the first sampled current. The DC component adjusting unit can also perform negative feedback adjustment based on a difference between a given value of the DC component and the DC component of the first sampled current to reduce the DC component of the first sampled current and output a DC suppression signal to the modulation signal generating unit. The given value of the DC component can be pre-set, for example, the given value of the DC component can be 0. In this case, the negative feedback adjustment can effectively reduce the DC component of the first sampled current, thereby suppressing the DC component of the inverter output current and improving the reliability of the circuit. As an example, the negative feedback adjustment can be proportional-integral-differential (PID) adjustment.

[0056] The harmonic compensation unit can receive the output current of the inverter and decompose the harmonic and reactive components from the output current of the inverter, and then output a harmonic compensation signal to the modulation signal generating unit based on a difference between the harmonic and reactive components and the first sampled current. The harmonic compensation signal can be used to offset the harmonic component in the load current and provide reactive power to the load, suppress the harmonic content in the UPS, and achieve high-quality power supply to the load.

[0057] Further, the modulation signal generating unit can take the inverse of the DC suppression signal and the harmonic compensation signal and sum them up to generate a target modulation signal to suppress the DC component of the output of the inverter and perform harmonic compensation for the load. It can be understood that when the first sampled current has a DC component, the target modulation signal for driving the inverter to work can be generated through the joint action of the DC component adjusting unit, the harmonic compensation unit, and the modulation signal generating unit, which can effectively suppress the DC component of the output of the inverter and perform harmonic compensation for the load, thereby offsetting the harmonic component in the load current, achieving high power quality power supply to the load, and also improving the quality of the AC power grid and reducing power loss.

[0058] In some possible implementations, as Figures 3 to 7Any of the illustrated, the UPS further comprises a filter module, the filter module is connected between the AC power grid and the rectifier. Among them, the filter module can be used for filtering the AC power input by the AC power grid, and then outputting the filtered AC power to the rectifier. Among them, the filter module can be an electromagnetic interference circuit (electromagnetic interference, EMI). It should be understood that the EMI circuit filters the AC power input by the AC power grid, which can filter out the harmonic interference of the AC power grid; in addition, the EMI circuit can also prevent the electromagnetic harmonic generated by the rear circuit from affecting the control UPS, so as to provide pure power to the load, thereby improving the reliability of the circuit. The AC power grid can be single-phase or three-phase AC power, and correspondingly, the output of the EMI can also be single-phase or three-phase AC power.

[0059] In this application, the UPS can adopt a single-phase structure or a multi-phase structure. When the UPS adopts a single-phase structure, the AC power grid is single-phase AC power, at this time, the connection mode and specific implementation of the rectifier, the inverter, the bypass module, the HCT1 and the CT2 can be referred to Figures 3 to 8 The connection mode of the rectifier, the inverter, the bypass module, the HCT1 and the CT2 and the corresponding specific implementation in any of the illustrated are not described here. The HCT1 can collect the first sampling current flowing from the bypass module to the AC power grid when the UPS provides active power to the load through the bypass module and provides reactive power to the load through the inverter, and can also collect the second sampling current input to the rectifier when the UPS provides active power to the load through the rectifier and the inverter and provides reactive power to the load through the inverter. The CT2 can collect the output current of the inverter when the UPS provides active power to the load through the bypass module and provides reactive power to the load through the inverter. Among them, the rectifier, the inverter, the bypass module, the HCT1 and the CT2 can be single-phase devices or multi-phase devices, which are not limited here.

[0060] In another embodiment, when the UPS adopts a multi-phase structure, the rectifier, the inverter, and the bypass module can be single-phase devices or multi-phase devices, which are not limited here. Optionally, when the rectifier, the inverter, and the bypass module are single-phase devices, the number of rectifiers, inverters, and bypass modules corresponds to the number of phases of the UPS, that is, each phase of the UPS is connected with a rectifier, an inverter, and a bypass module. For example, the UPS can adopt a three-phase four-wire structure, the AC power grid is three-phase 380V, 50 hertz (hertz, HZ) AC power, and the three phases of the three-phase AC power are called A phase, B phase and C phase. At this time, the A phase, the B phase and the C phase are connected with the rectifier, the inverter and the bypass module, and the number of rectifiers, inverters and bypass modules corresponds to the number of phases.

[0061] For example, refer to Figure 9 ,Figure 9 is another structural schematic diagram of the UPS provided by the present application. As shown in Figure 9 The UPS shown adopts a three-phase four-wire structure, and the AC power grid is an AC power of three-phase 380V and 50 Hertz (HZ). The three phases of the three-phase AC power are respectively referred to as A phase, B phase and C phase. When the rectifier, the inverter and the bypass module are multi-phase devices, the rectifier, the inverter and the bypass module can be three-phase devices, that is, the A phase, the B phase and the C phase are in one-to-one correspondence with each phase of the rectifier, the inverter and the bypass module. When the UPS adopts the three-phase four-wire structure, the HCT1 connected by each phase of the A phase, the B phase and the C phase of the AC power grid can be the same Hall sensor or different Hall sensors, and the CT2 connected by each phase can be the same current transformer or different current transformers. The specific determination can be made according to the actual application scene, and is not limited here.

[0062] It should be understood that the HCT1 can collect the first sampling current flowing from the bypass module to the AC power grid on each phase when the UPS provides active power to the load through the bypass module and provides reactive power to the load through the inverter, and can also collect the second sampling current input to the rectifier on each phase when the UPS provides active power to the load through the rectifier and the inverter and provides reactive power to the load through the inverter. The CT2 can collect the output current of the inverter on each phase when the UPS provides active power to the load through the bypass module and provides reactive power to the load through the inverter. For details, please refer to Figures 3 to 8 The corresponding embodiments are not described in detail here.

[0063] It can be understood that the current collection when the UPS provides active power to the load through different paths can be realized by multiplexing the HCT1, which can save the circuit devices included in the UPS, reduce the hardware cost and the occupied space, and also can reduce the complexity of the circuit structure of the UPS, improve the circuit stability of the UPS, and has high applicability.

[0064] It can be understood that the terms used in the specification of the application are only for the purpose of describing the specific embodiments and are not intended to limit the application. It can be understood that the terms "first", "second" and the like used in the application can be used herein to describe various information or data, but these elements are not limited by these terms. These terms are only used to distinguish the first information from another information. In several embodiments provided in the application, it should be understood that the disclosed circuit structure can be implemented in other ways. For example, the circuit embodiments described above are only schematic, for example, the division of the modules is only a logical function division, and actual implementation can have another division manner, for example, a plurality of modules can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the displayed or discussed elements can be indirect coupling or communication connection through some interfaces, devices or modules, which can be electrical, mechanical or other forms. The modules described as separate components can be or can not be physically separated, and the components shown as modules can be or can not be physical units. Part or all of the modules can be selected according to actual needs to implement the embodiments of the application. In addition, the functional modules in each embodiment of the application can be integrated in one processing unit, or each module can be physically present separately, or two or more modules can be integrated in one unit. The unit formed by the above modules can be realized in the form of hardware, or in the form of hardware plus software function unit.

Claims

1. An uninterruptible power supply, characterized by The uninterrupted power supply comprises a Hall sensor, a rectifier, an inverter and a bypass module; a first end of the Hall sensor is connected to an AC power grid, a second end of the Hall sensor is connected to an input end of the rectifier and a first end of the bypass module, an output end of the rectifier is connected to an input end of the inverter, an output end of the inverter and a second end of the bypass module are connected to a load; The Hall sensor is configured to collect a first sampling current flowing from the bypass module to the AC power grid when the uninterrupted power supply provides active power to the load through the bypass module and provides reactive power to the load through the inverter, and the first sampling current is used for drive control of the inverter; The Hall sensor is further configured to collect a second sampling current input to the rectifier when the uninterrupted power supply provides active power to the load through the rectifier and the inverter and provides reactive power to the load through the inverter, and the second sampling current is used for drive control of the rectifier.

2. The uninterruptible power supply of claim 1, wherein, The uninterrupted power supply further comprises a control module; The control module is configured to control the bypass module to provide active power to the load and control the inverter to provide reactive power to the load when input of the AC power grid is normal, acquire the first sampling current from the Hall sensor, and adjust a DC component output by the inverter based on the first sampling current to realize drive control of the inverter.

3. The uninterruptible power supply of claim 2, wherein, The control module is further configured to control the bypass module to be disconnected, control the rectifier and the inverter to provide active power to the load and control the inverter to provide reactive power to the load when input of the AC power grid is detected to be abnormal, acquire the second sampling current from the Hall sensor, and adjust an input current of the rectifier based on the second sampling current to realize drive control of the rectifier.

4. The uninterruptible power supply of claim 2, wherein, The uninterrupted power supply further comprises a current transformer; a first end of the current transformer is connected to an output end of the inverter, and a second end of the current transformer is connected to the load; The current transformer is configured to collect an output current of the inverter when the uninterrupted power supply provides active power to the load through the bypass module and provides reactive power to the load through the inverter; The control module is further configured to acquire the output current from the current transformer and perform harmonic compensation on the load based on the output current and the first sampling current.

5. The uninterruptible power supply of claim 4, wherein, The control module comprises a DC component adjusting unit, a harmonic compensation unit and a modulation signal generating unit; The DC component adjusting unit is configured to output a DC suppression signal to the modulation signal generating unit based on the first sampling current when it is detected that the first sampling current has a DC component; The DC suppression signal is used to suppress output DC of the inverter; The harmonic compensation unit is configured to output a harmonic compensation signal to the modulation signal generating unit based on the output inductive current and the first sampling current; and the harmonic compensation signal is used to perform harmonic compensation on the load. The modulation signal generation unit is configured to generate a target modulation signal based on the DC suppression signal and the harmonic compensation signal. The target modulation signal is configured to suppress the DC component of the output of the inverter and compensate for harmonics of the load.

6. The uninterruptible power supply of any of claims 1 to 5, wherein, The bypass module comprises a static input switch. The static input switch is configured to control the bypass module to turn on or turn off the connection between the AC power grid and the load.

7. The uninterruptible power supply of any of claims 1 to 5, wherein, The uninterruptible power supply further comprises a filter module connected between the AC power grid and the rectifier. The filter module is configured to filter the AC power input from the AC power grid.

8. The uninterruptible power supply of any one of claims 1 to 5, further comprising a DC power source configured to supply power to the inverter when the uninterruptible power supply supplies active power to the load through the bypass module and supplies reactive power to the load through the inverter.

9. The uninterruptible power supply of claim 8, wherein, The DC power source comprises a battery and a DC converter, wherein an output of the battery is connected to an input of the DC converter, and an output of the DC converter is connected to an output of the rectifier and an input of the inverter. The DC converter is configured to convert power provided by the battery into target power to supply power to the inverter when the uninterruptible power supply supplies active power to the load through the bypass module and supplies reactive power to the load through the inverter, wherein an energy amount of the target power is based on a demand of the inverter.

10. The uninterruptible power supply of claim 9, wherein, The rectifier is further configured to obtain AC power from the AC power grid and convert the AC power into DC power through the DC converter to charge the battery when the rectifier supplies active power to the load.

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