Low-voltage power distribution switch and power supply device

Abstract

The present invention relates to the field of low-voltage power distribution. Particularly disclosed are a low-voltage power distribution switch and a power supply device. The power distribution switch comprises: a switch module, multiple current measurement modules, and a metering module, wherein multiple input ends of the switch module are suitable for being correspondingly connected to power supply lines of multiple phases, and the switch module is used for connecting or disconnecting the power supply lines of multiple phases; input ends of the multiple current measurement modules are correspondingly connected to multiple output ends of the switch module, output ends of the multiple current measurement modules are suitable for being correspondingly connected to the power supply lines of multiple phases, each current measurement module comprises multiple current branches and current measurement units, the multiple current branches are connected in parallel between the input ends and output ends of the corresponding current measurement modules, and the multiple current measurement units are used for measuring the current of each current branch to obtain a current measurement signal of a power supply line of a corresponding phase; and the metering module is used for determining first electric energy metering data of the power supply lines of multiple phases on the basis of multiple current measurement signals. The power distribution switch can improve the linearity and accuracy of an electric energy metering function.

Description

Low-voltage distribution switches and power supply equipment Technical Field

[0001] The present invention relates to the field of low-voltage power distribution, and in particular to a low-voltage power distribution switch and power supply equipment. Background Art

[0002] In traditional low-voltage power distribution, low-voltage distribution switches are primarily used to switch and connect power lines and provide power protection for circuits. However, with the widespread adoption of renewable energy, distribution switches are also being used to integrate renewable energy grids into the main power grid and monitor renewable energy quality. To adapt to these changing needs, the National Energy Administration has developed standards for distribution switches, detailing application scenarios and performance indicators. Energy metering is a key function of distribution switches, enabling applications such as energy billing, line loss analysis, and fault analysis. Currently, the design of a low-voltage distribution switch in related technology is as follows: Three current transformers and three voltage transformers are used, and a SAR (Successive Approximation Register) ADC is used to connect six analog signals—three current signals and three voltage signals—to each. This ADC samples the six signals in a time-sharing manner. A microcontroller then performs real-time analysis of the sampled values ​​and performs overvoltage and overcurrent protection analysis, thereby implementing corresponding power protection and energy analysis functions.

[0003] The disadvantage of the above-mentioned related technologies is that since the current variation range in the low-voltage distribution station area is large, and the variation range can reach 1 ampere to 400 amperes, this will cause the low-voltage distribution switch to easily produce transformer magnetic saturation, which in turn leads to inaccurate current measurement, thereby making the electric energy metering linearity of the low-voltage distribution switch low. For example, the distribution switch cannot achieve an electric energy metering linearity of 0.2S level.

[0004] Summary of the Invention

[0005] The present invention aims to solve, at least to a certain extent, one of the technical problems in the related art. To this end, a first object of the present invention is to provide a low-voltage power distribution switch. By providing multiple current detection modules and metering modules, each current detection module includes multiple current detection units and multiple current branches connected in parallel. When the low-voltage power distribution switch is operating normally, the multiple current branches can achieve a shunting effect to reduce the current value passing through each current branch, thereby improving the accuracy and linearity of the multiple branch current detection signals obtained by the current detection units, thereby improving the linearity and accuracy of the electric energy metering function.

[0006] A second objective of the present invention is to provide a power supply device.

[0007] To achieve the above-mentioned purpose, the first embodiment of the present invention proposes a low-voltage distribution switch, comprising: a switch module, wherein the multiple input terminals of the switch module are suitable for correspondingly connecting to a multi-phase power supply line as the voltage input terminal of the low-voltage distribution switch, and the switch module is used to connect or disconnect the multi-phase power supply line; multiple current detection modules, wherein the input terminals of the multiple current detection modules are correspondingly connected to the multiple output terminals of the switch module, and the output terminals of the multiple current detection modules are suitable for correspondingly connecting to the multi-phase power supply line as the voltage output terminals of the low-voltage distribution switch, each current detection module includes multiple current branches and current detection units, and the multiple current branches are connected in parallel between the input terminal and the output terminal of the corresponding current detection module, and the current detection unit is used to detect the current of each current branch to obtain multiple branch current detection signals, and based on the multiple branches a voltage detection module, wherein multiple input terminals of the voltage detection module are connected to multiple output terminals of the switch module and a neutral line input terminal of the low-voltage distribution switch, and the neutral line input terminal is suitable for being connected to the neutral line of the power supply line, and the voltage detection module is used to detect the voltage of each phase power supply line in the multi-phase power supply line to obtain multiple voltage detection signals; a metering module, wherein the metering module is respectively connected to the voltage detection module and the multiple current detection units, and the metering module is used to sample the multiple voltage detection signals and the multiple current detection signals, and obtain multiple first voltages according to the multiple voltage detection signals, and calculate multiple first currents according to the multiple current detection signals, and determine the first electric energy metering data of the multi-phase power supply line based on the multiple first voltages and the multiple first currents.

[0008] According to the low-voltage distribution switch of an embodiment of the present invention, by providing multiple current detection modules and metering modules, and each current detection module includes multiple current detection units and multiple current branches connected in parallel, when the low-voltage distribution switch is operating normally, the multiple current branches can achieve a shunting effect to reduce the current value passing through each current branch, thereby improving the accuracy and linearity of the multiple branch current detection signals obtained by the current detection unit, and further improving the linearity and accuracy of the electric energy metering function.

[0009] According to one embodiment of the present invention, the current detection unit includes: multiple current transformers, the input ends of the multiple current transformers are coupled and connected to the multiple current branches respectively, and each current transformer is used to detect the current of the corresponding current branch to obtain a branch current detection signal; an adder module, the input end of the adder module is connected to the output ends of the multiple current transformers, the output end of the adder module is connected to the metering module, and the adder module is used to sum the multiple branch current detection signals to obtain the current detection signal of the corresponding phase power supply line.

[0010] According to one embodiment of the present invention, the adder module includes: multiple signal buffers, the input ends of the multiple signal buffers are correspondingly connected to the output ends of the multiple current transformers, and each signal buffer is used to buffer the corresponding branch current detection signal; an adder, the multiple input ends of the adder are correspondingly connected to the output ends of the multiple signal buffers, the output end of the adder is connected to the metering module, and the adder is used to sum the buffered multiple branch current detection signals to obtain the current detection signal of the corresponding phase power supply line.

[0011] According to one embodiment of the present invention, the signal buffer includes: a first resistor, one end of the first resistor is connected to the first output end of the corresponding current transformer; a second resistor, one end of the second resistor is connected to the second output end of the corresponding current transformer; a first operational amplifier, a first input end of the first operational amplifier is connected to the other end of the first resistor, a second input end of the first operational amplifier is connected to the other end of the second resistor, and an output end of the first operational amplifier is connected to the corresponding input end of the adder; a third resistor, the third resistor is connected in series between the second input end of the first operational amplifier and ground; and a fourth resistor, the fourth resistor is connected in series between the first input end and the output end of the first operational amplifier.

[0012] According to an embodiment of the present invention, the first resistor, the second resistor, the third resistor, and the fourth resistor have the same resistance value.

[0013] According to one embodiment of the present invention, the adder includes: a plurality of fifth resistors, one end of each of the plurality of fifth resistors being connected to the output ends of the plurality of signal buffers, respectively; a second operational amplifier, a first input end of the second operational amplifier being connected to the other ends of the plurality of fifth resistors, a second input end of the second operational amplifier being grounded, and an output end of the second operational amplifier being connected to the metering module; and a sixth resistor connected in series between the first input end and the output end of the second operational amplifier.

[0014] According to an embodiment of the present invention, the fifth resistor and the sixth resistor have the same resistance value.

[0015] According to one embodiment of the present invention, the current detection module further includes: a shunt, wherein the input end of the shunt serves as the input end of the current detection module; a combiner, wherein the multiple input ends of the combiner are correspondingly connected to the multiple output ends of the shunt through multiple voltage connection lines, and the output end of the combiner serves as the output end of the current detection module; wherein, multiple current branches are formed by the shunt, the combiner and the multiple voltage connection lines, and are connected in parallel between the input end and the output end of the corresponding current detection module.

[0016] According to one embodiment of the present invention, the shunt includes a first conductive member, a voltage input line and a plurality of first voltage branch lines, one end of the voltage input line serves as an input end of the shunt, the other end of the voltage input line is connected to the input end of the first conductive member, one end of the plurality of first voltage branch lines is connected to the plurality of output ends of the first conductive member, and the other end of the plurality of first voltage branch lines serves as the plurality of output ends of the shunt, wherein the plurality of output ends of the first conductive member are located on the same side of the first conductive member, and the plurality of output ends of the first conductive member and the input end of the first conductive member are located on different sides of the first conductive member.

[0017] According to one embodiment of the present invention, the combiner includes a second conductive member, a plurality of second voltage branches and a voltage output line, one end of the plurality of second voltage branches serves as a plurality of input ends of the combiner, the other end of the plurality of second voltage branches is connected to the plurality of input ends of the second conductive member, one end of the voltage output line is connected to the output end of the second conductive member, and the other end of the voltage output line serves as the output end of the combiner, wherein the plurality of input ends of the second conductive member are located on the same side of the second conductive member, and the plurality of input ends of the second conductive member and the output end of the second conductive member are located on different sides of the second conductive member.

[0018] According to one embodiment of the present invention, multiple current transformers are divided into at least one transformer group, which includes two current transformers symmetrically arranged on both sides of the support plate and with opposite winding directions, and the winding directions of two adjacent current transformers located on the same side of the support plate are opposite.

[0019] According to one embodiment of the present invention, the low-voltage distribution switch further includes: an ADC sampling module, the ADC sampling module is connected to multiple current detection units, and the ADC sampling module is used to sample multiple current detection signals to obtain multiple current sampling signals, so as to perform power supply protection based on the multiple current sampling signals.

[0020] According to one embodiment of the present invention, the ADC sampling module is also connected to the voltage detection module, and the ADC sampling module is further used to sample multiple voltage detection signals to obtain multiple voltage sampling signals, so as to perform power supply protection based on multiple current sampling signals and multiple voltage sampling signals.

[0021] According to one embodiment of the present invention, the low-voltage distribution switch further includes: a main control module, the main control module being connected to the metering module and the ADC sampling module, wherein the main control module is configured to, when the metering module is not failed, obtain first electric energy metering data from the metering module; when the metering module is failed, obtain multiple current sampling signals and multiple voltage sampling signals from the ADC sampling module, and determine the first electric energy metering data based on the multiple current sampling signals and the multiple voltage sampling signals; the main control module is further configured to, when the ADC sampling module is not failed, obtain multiple current sampling signals and multiple voltage sampling signals from the ADC sampling module so as to perform power supply protection based on the multiple current sampling signals and the multiple voltage sampling signals; when the ADC sampling module is failed, obtain multiple first currents and multiple first voltages from the metering module so as to perform power supply protection based on the multiple first currents and multiple first voltages.

[0022] According to one embodiment of the present invention, the main control module is further configured to obtain a plurality of voltage sampling signals from the ADC sampling module and a plurality of first voltages from the metering module, and to determine whether the metering module and the ADC sampling module have failed based on the plurality of voltage sampling signals and the plurality of first voltages.

[0023] According to one embodiment of the present invention, the main control module is configured to calculate a plurality of second voltages based on a plurality of voltage sampling signals, obtain a voltage difference between each first voltage and a corresponding second voltage to obtain a plurality of voltage difference values, and determine whether the metering module and the ADC sampling module have failed based on the plurality of first voltages and the plurality of second voltages when any voltage difference value among the plurality of voltage difference values ​​is greater than or equal to a first preset voltage difference threshold.

[0024] According to one embodiment of the present invention, the main control module is configured to determine whether the metering module and the ADC sampling module have failed based on at least one of a DC component, an amplitude, a waveform distortion, a power, a power factor, a frequency, and a phase sequence corresponding to the plurality of first voltages and the plurality of second voltages.

[0025] According to one embodiment of the present invention, the main control module is configured to determine that the metering module has failed when the DC component of the first voltage is greater than a preset DC component; and to determine that the ADC sampling module has failed when the DC component of the second voltage is greater than a preset DC component.

[0026] According to one embodiment of the present invention, the main control module is configured to determine that the metering module has failed when the amplitude of the first voltage is not within a preset amplitude range; and to determine that the ADC sampling module has failed when the amplitude of the second voltage is not within the preset amplitude range.

[0027] According to one embodiment of the present invention, the main control module is configured to determine that the metering module has failed when the waveform distortion of the first voltage is greater than a first preset distortion, or when the waveform distortion of the first voltage is greater than the waveform distortion of the second voltage, and the difference between the waveform distortion of the first voltage and the waveform distortion of the second voltage is greater than a second preset distortion; and to determine that the ADC sampling module has failed when the waveform distortion of the second voltage is greater than the first preset distortion, or when the waveform distortion of the second voltage is greater than the waveform distortion of the first voltage, and the difference between the waveform distortion of the second voltage and the waveform distortion of the first voltage is greater than a second preset distortion.

[0028] According to one embodiment of the present invention, the main control module is configured to determine that the metering module has failed when the first power corresponding to the first voltage is negative; and to determine that the ADC sampling module has failed when the second power corresponding to the second voltage is negative.

[0029] According to one embodiment of the present invention, the main control module is configured to determine that the metering module has failed when a first power factor corresponding to the first voltage is less than a preset power factor; and to determine that the ADC sampling module has failed when a second power factor corresponding to the second voltage is less than a preset power factor.

[0030] According to one embodiment of the present invention, the main control module is configured to determine that the ADC sampling module has failed when the frequency difference between the frequency of the first voltage and the preset frequency is smaller than the frequency difference between the frequency of the second voltage and the preset frequency, and the frequency difference between the frequency of the second voltage and the frequency of the first voltage is larger than the preset frequency difference; and to determine that the metering module has failed when the frequency difference between the frequency of the second voltage and the preset frequency is smaller than the frequency difference between the frequency of the first voltage and the preset frequency, and the frequency difference between the frequency of the first voltage and the frequency of the second voltage is larger than the preset frequency difference.

[0031] According to one embodiment of the present invention, the main control module is configured to determine that the metering module has failed when the phase sequence of the plurality of first voltages is different from a preset phase sequence; and to determine that the ADC sampling module has failed when the phase sequence of the plurality of second voltages is different from the preset phase sequence.

[0032] According to one embodiment of the present invention, a first frequency at which the main control module obtains the multiple first currents and multiple first voltages from the metering module is lower than a second frequency at which the main control module obtains the multiple current sampling signals and the multiple voltage sampling signals from the ADC sampling module. The main control module is further configured to perform power supply protection based on the multiple first currents, the multiple first voltages, and the first frequency when the ADC sampling module fails.

[0033] According to one embodiment of the present invention, the main control module is also used to correct multiple first voltages and multiple first currents based on the ratio of the second voltage to the first voltage when each voltage difference among the multiple voltage differences is less than a first preset voltage difference threshold and greater than a second preset voltage difference threshold, wherein the second preset voltage difference threshold is less than the first preset voltage difference threshold.

[0034] According to one embodiment of the present invention, the main control module is further configured to analyze and process the first electric energy metering data to obtain second electric energy metering data.

[0035] According to one embodiment of the present invention, the low-voltage distribution switch also includes: a protection control module, which is connected to the switch module and is used to control the switch module; the main control module is also connected to the protection control module, and the main control module is also used to generate a protection signal based on multiple current sampling signals and multiple voltage sampling signals, or based on multiple first currents and multiple first voltages, and send it to the protection control module, so that the protection control module controls the switch module to disconnect based on the protection signal for power supply protection.

[0036] According to one embodiment of the present invention, the low-voltage distribution switch further includes: a status acquisition module, which is connected to the switch module and the main control module, and is used to obtain the switch status and / or power supply protection mode of the switch module and send it to the main control module.

[0037] According to one embodiment of the present invention, the low-voltage distribution switch further includes: a proxy module and an isolation module, the proxy module is connected to the metering module, the ADC sampling module, the protection control module, the status acquisition module and the isolation module, and the isolation module is connected to the main control module, wherein the proxy module is used to obtain first electric energy metering data, multiple first voltages, multiple first currents, multiple voltage sampling signals, multiple current sampling signals, and switch status and / or power supply protection mode, and send them to the main control module through the isolation module, and receive the protection signal through the isolation module and send it to the protection control module.

[0038] According to one embodiment of the present invention, the priority of the proxy module in sending data from the metering module is lower than the priority of sending data from the ADC sampling module and is higher than the priority of sending data from the status acquisition module.

[0039] According to one embodiment of the present invention, the low-voltage distribution switch also includes: a first power supply module and a second power supply module, the input end of the first power supply module is connected to multiple input ends of the switch module, the output end of the first power supply module is connected to the input end of the second power supply module, and the output end of the second power supply module is connected to the isolation module, wherein the first power supply module is used to convert the first power supply voltage provided by the multi-phase power supply line into a second power supply voltage, and the second power supply module is used to convert the second power supply voltage into a third power supply voltage and provide it to the isolation module, and power is supplied to the agent module and the main control module through the isolation module.

[0040] To achieve the above-mentioned object, a second embodiment of the present invention provides a power supply device, including the aforementioned low-voltage distribution switch.

[0041] The power supply device according to the embodiment of the present invention can implement an electric energy metering function with high linearity and accuracy through the aforementioned low-voltage power distribution switch, thereby achieving optimization of the power supply device.

[0042] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] FIG1 is a schematic structural diagram of a low-voltage power distribution switch according to an embodiment of the present invention;

[0044] FIG2 is a schematic structural diagram of a current detection unit according to an embodiment of the present invention;

[0045] FIG3 is a schematic structural diagram of an adder module according to an embodiment of the present invention;

[0046] FIG4 is a circuit diagram of a data buffer according to an embodiment of the present invention;

[0047] FIG5 is a circuit diagram of an adder according to an embodiment of the present invention;

[0048] FIG6 is a schematic structural diagram of a flow divider according to an embodiment of the present invention;

[0049] 7a and 7b are schematic diagrams showing an arrangement of multiple current transformers according to an embodiment of the present invention;

[0050] FIG8 is a schematic structural diagram of a low-voltage power distribution switch according to another embodiment of the present invention;

[0051] FIG9 is a schematic structural diagram of a low-voltage power distribution switch according to another embodiment of the present invention;

[0052] FIG10 is a schematic diagram showing the connection of a main control module in a direct communication mode according to an embodiment of the present invention;

[0053] FIG11 is a schematic structural diagram of an isolation module according to an embodiment of the present invention;

[0054] FIG12 is a schematic structural diagram of a power supply device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0055] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.

[0056] The following describes the low-voltage power distribution switch and power supply equipment proposed in the embodiments of the present invention with reference to the accompanying drawings.

[0057] FIG1 is a schematic structural diagram of a low-voltage power distribution switch according to an embodiment of the present invention. Referring to FIG1 , the low-voltage power distribution switch 100 includes a switch module 110 , a plurality of current detection modules 120 and a metering module 130 .

[0058] Among them, the multiple input ends of the switch module 110 are suitable for correspondingly connecting to the multi-phase power supply line as the voltage input end of the low-voltage distribution switch 100, and the switch module 110 is used to connect or disconnect the multi-phase power supply line; the input ends of the multiple current detection modules 120 are correspondingly connected to the multiple output ends of the switch module 110, and the output ends of the multiple current detection modules 120 are suitable for correspondingly connecting to the multi-phase power supply line as the voltage output end of the low-voltage distribution switch 100, each current detection module 120 includes multiple current branches 121 and current detection units 122, multiple current branches 121 is connected in parallel between the input end and the output end of the corresponding current detection module 120, and the current detection unit 122 is used to detect the current of each current branch 121 to obtain multiple branch current detection signals, and obtain the current detection signal of the corresponding phase power supply line based on the multiple branch current detection signals; the metering module 130 is connected to the multiple current detection units 122, and the metering module 130 is used to sample the multiple current detection signals, and calculate the multiple first currents according to the multiple current detection signals, and determine the first electric energy metering data of the multi-phase power supply line based on the multiple first currents.

[0059] Specifically, the multi-phase power supply circuit in the embodiment of the present invention may include various multi-phase power supply circuits. The following describes the low-voltage distribution switch 100 in the embodiment of the present invention using a three-phase power supply circuit as an example. Currently, the domestic three-phase power supply circuit is a three-phase four-wire system. As shown in FIG1 , the multi-phase power supply circuit includes three-phase voltage input lines ABC and a voltage neutral line (not shown). In this case, the low-voltage distribution switch 100 includes three current detection modules 120. The three-phase voltage input lines ABC are respectively connected to multiple input terminals of the switch module 110. The multi-phase power supply circuit also includes three-phase voltage output lines ABC, which are respectively connected to the output terminals of the corresponding current detection modules 120. The low-voltage distribution switch 100 can control the multi-phase power supply circuit to be turned on or off through the switch module 110. Referring to FIG1 , when the switch module 110 is turned on, the three-phase input lines ABC of the multi-phase power supply circuit can be connected to the corresponding three-phase output lines through the switch module 110 and the corresponding current detection module 120, thereby enabling the low-voltage distribution switch 100 to achieve the function of switching and connecting the power supply circuits.

[0060] Continuing with reference to FIG1 , each current detection module 120 includes multiple current branches and a current detection unit 122. As can be seen from the current characteristics, when the switch module 110 is turned on, the sum of the currents in the multiple current branches 121 in each current detection module 120 is equal to the current in the corresponding phase power supply line. Therefore, after the current detection unit 122 detects the currents in the multiple current branches 121 in a current detection module 120 and obtains multiple branch current detection signals, the current detection unit 122 can add the multiple branch current detection signals to obtain the current detection signal for the corresponding phase power supply line. Subsequently, the metering module 130 can sample these three current detection signals and determine the first current of the corresponding phase power supply line based on the multiple current detection signals, and determine the first ionization energy measurement data of the multi-phase power supply line at this time based on the three first currents. This achieves the electric energy metering function of the low-voltage distribution switch 100.

[0061] Furthermore, current transformers are commonly used in related art to measure the current of each phase of the power supply line. However, due to the large fluctuations in the current of each phase of the power supply line, when the current is too high, the transformer core can easily saturate, resulting in secondary signal distortion, which in turn reduces the accuracy of the measured data. However, if the core saturation problem is overcome, the linearity of the power supply line will deteriorate when the current is relatively low. Therefore, the current transformers in related art cannot achieve the required accuracy and linearity of 0.2S level, where 0.2 represents the current transformer's maximum ratio error of less than 0.2% and the angle error of less than 10° at 50Hz and rated current. S represents a special current transformer, which requires sufficiently high accuracy within the load range of 1%-120%. However, in the embodiments of the present invention, by providing multiple current branches 121 in each current detection module 120, the current value passing through each current branch 121 is reduced through shunting, and the current fluctuation in each current branch 121 is also relatively low, which is equivalent to expanding the measurement range of the current value. Therefore, when the current detection unit 122 of the embodiment of the present invention detects the current in the current branch 121, it will not be affected by excessive current fluctuations, so the detected branch current detection signal has greater advantages in accuracy and linearity. Therefore, the first electric energy metering data determined by the metering unit 130 of the embodiment of the present invention also has higher accuracy and linearity.

[0062] In the above embodiment, multiple current detection modules and metering modules are set up, and each current detection module includes multiple current detection units and multiple current branches connected in parallel, each current detection unit is connected in parallel with the corresponding current branch. When the low-voltage distribution switch is turned on, the current detection unit can detect the current of each current branch to obtain multiple branch current detection signals, and obtain the current detection signal of the corresponding phase power supply line based on the multiple branch current detection signals. Subsequently, the metering module can sample the multiple current detection signals and calculate multiple first currents and first electric energy metering data, thereby realizing the electric energy metering function; at the same time, the multiple current branches can achieve the effect of shunting to reduce the current value passing through each current branch, thereby improving the accuracy and linearity of the multiple branch current detection signals obtained by the current detection unit, and thereby improving the linearity and accuracy of the electric energy metering function.

[0063] Optionally, when the multi-phase power supply line is a three-phase four-wire power supply line, the metering module 130 can be implemented using chips such as ATT7022 or RN8302. The inputs of these metering chips have 3 voltage signals and 4 current signals, which are mainly used to measure the voltage effective value, current effective value, power, electric energy and other data of the low-voltage line, thereby realizing the electric energy metering function of the low-voltage distribution switch in the above-mentioned invention embodiment.

[0064] In some embodiments, as shown in Figure 2, the current detection unit 122 includes: multiple current transformers LH and an adder module 1221, wherein the input ends of the multiple current transformers LH are coupled and connected to the multiple current branches 121 respectively, and each current transformer LH is used to detect the current of the corresponding current branch 121 to obtain a branch current detection signal; the input end of the adder module 1221 is connected to the output ends of the multiple current transformers LH, and the output end of the adder module 1221 is connected to the metering module 130, and the adder module 1221 is used to sum the multiple branch current detection signals to obtain the current detection signal of the corresponding phase power supply line.

[0065] Specifically, as can be seen from the above, in each current detection module 120, the sum of the currents in the multiple current branches 121 is equal to the current of the power supply line corresponding to the phase of the current detection unit 122. Therefore, multiple current transformers LH and adder modules 1221 can be provided in the current detection unit 122, wherein each current transformer LH is coupled to multiple current branches 121, as shown in Figure 2, thereby detecting the current of the corresponding current branch 121 and outputting it to the adder module 1221, so that the adder module 1221 obtains multiple branch current detection signals. Subsequently, the adder module 1221 sums the multiple branch current detection signals to obtain the current detection signal of the corresponding phase power supply line. As a result, the current detection unit realizes the function of detecting and obtaining multiple branch current detection signals, and thereby obtaining the current detection signal of the corresponding phase power supply line.

[0066] In some embodiments, as shown in reference Figure 3, the adder module 1221 includes: multiple signal buffers BUF and an adder ADD, wherein the input ends of the multiple signal buffers BUF are correspondingly connected to the output ends of multiple current transformers LH, and each signal buffer BUF is used to buffer the corresponding branch current detection signal; the multiple input ends of the adder ADD are correspondingly connected to the output ends of the multiple signal buffers BUF, the output end of the adder ADD is connected to the metering module 130, and the adder ADD is used to sum the buffered multiple branch current detection signals to obtain the current detection signal of the corresponding phase power supply line.

[0067] Specifically, as shown in FIG3 , multiple signal buffers BUF are disposed between corresponding current transformers LH and the input terminals of adders ADD. The signal buffers BUF are capable of buffering the branch current detection signals output by the corresponding current transformers LH and then inputting them into the adders ADD, enabling the adders ADD to obtain multiple branch current detection signals. The adders ADD are primarily configured to sum the multiple buffered branch current detection signals to obtain the current detection signals for the corresponding phase power supply lines, thereby fulfilling the corresponding function of adder module 1221. Simultaneously, the signal buffers BUF are capable of suppressing common-mode signals on the secondary output conductive wiring harness of the current transformers LH, thereby improving the common-mode rejection ratio and reducing distortion of the branch current detection signals during transmission. The signal buffers BUF also provide signal isolation, preventing the current at the adder ADD terminals from affecting the normal operation of the current transformers LH, thereby improving the accuracy of the ultimately determined current detection signals.

[0068] Further, referring to Figure 4, the signal buffer BUF includes: a first resistor R1, a second resistor R2, a first operational amplifier U1, a third resistor R3 and a fourth resistor R4, wherein one end of the first resistor R1 is connected to the first output end of the corresponding current transformer LH; one end of the second resistor R2 is connected to the second output end of the corresponding current transformer LH; the first input end of the first operational amplifier U1 is connected to the other end of the first resistor R1, the second input end of the first operational amplifier U1 is connected to the other end of the second resistor R2, and the output end of the first operational amplifier U1 is connected to the corresponding input end of the adder ADD; the third resistor R3 is connected in series between the second input end of the first operational amplifier U1 and ground; and the fourth resistor R4 is connected in series between the first input end and the output end of the first operational amplifier U1.

[0069] Furthermore, the first resistor R1 , the second resistor R2 , the third resistor R3 and the fourth resistor R4 have the same resistance value.

[0070] Specifically, the current transformer LH primarily measures the current in the corresponding current branch based on the principle of electromagnetic induction. The two output terminals of the secondary winding of the current transformer are the first and second output terminals of the current transformer LH. Referring to FIG4 , the first and second output terminals of the current transformer LH are connected to one end of a first resistor R1 and a second resistor R2, respectively, to input the detected branch current detection signal to the signal buffer BUF. In this case, the current transformer LH can be equivalent to a load resistor RCT. The first to fourth resistors (R1-R4) in the signal buffer BUF and the first operational amplifier U1 form a differential amplifier circuit that can differentially amplify the branch current detection signal input by the current transformer LH. The amplification factor depends on the resistance values ​​of the first to fourth resistors R1 to R4. Furthermore, since the signal buffer in this embodiment of the present invention does not need to perform signal amplification, the resistance values ​​of the first to fourth resistors can be the same. In this case, the amplification factor of the signal buffer BUF is 1, thereby achieving the signal buffer's function of improving the common-mode rejection ratio and achieving circuit isolation. As a specific embodiment, the first operational amplifier U1 may use an OP1177 chip, and the resistance values ​​of the first resistor to the fourth resistor may be 100KΩ. In this case, the signal buffer BUF also has the function of increasing the input impedance of the adder module 1221.

[0071] In some embodiments, as shown in FIG5 , the adder ADD includes: a plurality of fifth resistors R5 , one end of each of the plurality of fifth resistors R5 being connected to the output ends of the plurality of signal buffers BUF; a second operational amplifier U2 , a first input end of the second operational amplifier U2 being connected to the other ends of the plurality of fifth resistors R5 , a second input end of the second operational amplifier U2 being grounded GND, and an output end of the second operational amplifier U2 being connected to the metering module 130 ; and a sixth resistor R6 , the sixth resistor R6 being connected in series between the first input end and the output end of the second operational amplifier U2 .

[0072] Furthermore, the fifth resistor R5 and the sixth resistor R6 have the same resistance.

[0073] Specifically, as shown in FIG5 , the second operational amplifier U2, the fifth resistor R5, and the sixth resistor R6 form a closed-loop amplification circuit. Since the output terminals of multiple signal buffers BUF are connected in parallel to the first input terminal of the second operational amplifier U2 via the multiple fifth resistors R5, the second operational amplifier U2 can add and amplify multiple branch current detection signals. The amplification factor is determined by the resistance values ​​of the sixth resistor R6 and the fifth resistor R5. The fifth and sixth resistors can have the same resistance value. For example, the fifth and sixth resistors can have a resistance value of 1 kΩ, resulting in an amplification factor of 1 for the closed-loop amplification circuit. The adder ADD can add the multiple branch current detection signals to obtain the current detection signal for the corresponding phase power supply line. Furthermore, the second operational amplifier U2 in the adder ADD also improves output drive capability. The specific principles will not be elaborated here.

[0074] Optionally, the second operational amplifier U2 may be an OP1177 chip, which has the advantages of low noise, high precision, and low power consumption, thereby enabling optimization of the adder ADD.

[0075] In some embodiments, as shown in reference Figure 6, the current detection module 120 also includes: a shunt 123 and a combiner 124, the input end of the shunt 123 serves as the input end of the current detection module 120; multiple input ends of the combiner 124 are correspondingly connected to multiple output ends of the shunt 123 through multiple voltage connection lines, and the output end of the combiner 124 serves as the output end of the current detection module 120; wherein, multiple current branches 121 are formed by the shunt 123, the combiner 124 and the multiple voltage connection lines, and are connected in parallel between the input end and the output end of the corresponding current detection module 120.

[0076] Furthermore, the shunt 123 includes a first conductive member CP1, a voltage input line VIN and a plurality of first voltage branch lines DF1, one end of the voltage input line VIN serves as an input end of the shunt 123, the other end of the voltage input line VIN is connected to the input end of the first conductive member CP1, one end of the plurality of first voltage branch lines DF1 is connected to the plurality of output ends of the first conductive member CP1, and the other end of the plurality of first voltage branch lines DF1 serves as the plurality of output ends of the shunt 123, wherein the plurality of output ends of the first conductive member CP1 are located on the same side of the first conductive member CP1, and the plurality of output ends of the first conductive member CP1 and the input end of the first conductive member CP1 are located on different sides of the first conductive member CP1.

[0077] Furthermore, the combiner 124 includes a second conductive part CP2, a plurality of second voltage branches DF2 and a voltage output line VOUT, one end of the plurality of second voltage branches DF2 serves as a plurality of input ends of the combiner 124, the other end of the plurality of second voltage branches DF2 is connected to the plurality of input ends of the second conductive part CP2, one end of the voltage output line VOUT is connected to the output end of the second conductive part CP2, and the other end of the voltage output line VOUT serves as the output end of the combiner 124, wherein the plurality of input ends of the second conductive part CP2 are located on the same side of the second conductive part CP2, and the plurality of input ends of the second conductive part CP2 and the output end of the second conductive part CP2 are located on different sides of the second conductive part CP2.

[0078] Specifically, referring to FIG6 , the first conductive member CP1 and the second conductive member CP2 can be implemented using metal terminals with good electrical conductivity. The single-phase power supply line is connected to the first conductive member CP1 via the voltage input line VIN. The first conductive member CP1 shunts the current of the voltage input line VIN to multiple first voltage branches DF1, wherein the other ends of the multiple first voltage branches DF1 serve as multiple output ends of the shunt 123 and are connected to the corresponding multiple second voltage branches DF2 via multiple voltage connection lines. Therefore, the shunted current can be transmitted to the multiple second voltage branches DF2 of the second conductive member CP2; subsequently, the second conductive member CP2 merges the currents on the multiple second voltage branches DF2 and outputs them to the single-phase power supply line via the output end of the second conductive member CP2 and the voltage output line VOUT. In the above process, the current shunt 121 is composed of the first voltage branch DF1, the voltage connection line, and the second voltage branch DF2. As a result, the shunt 123, the combiner 124, and the multiple voltage connection lines achieve the function of forming multiple current branches.

[0079] Optionally, as shown in reference Figure 6, a current transformer row can be used to realize the coupling connection between the current transformer LH and the corresponding current branch 121, wherein the current transformer row contains multiple current transformers LH with the same structure, the same material, and the same parameter indicators, so as to ensure that the secondary signals of the current transformer LH are the same; at the same time, the material, length, thickness, and impedance of the conductors of each first voltage branch DF1 and the corresponding second voltage branch DF2 can be made the same to ensure that the voltage and current on each current branch are the same.

[0080] Optionally, multiple current transformers LH are divided into at least one transformer group, which includes two current transformers LH symmetrically arranged on both sides of the support plate and with opposite winding directions, and the winding directions of two adjacent current transformers LH located on the same side of the support plate are opposite.

[0081] Specifically, there is usually a common-mode interference signal in the current signal of the multiple current branches 121, and this interference signal will affect the current signal value measured by the current transformer LH, resulting in inaccurate measurement. Therefore, the multiple current transformers LH can be set to an even number, and at least one transformer group can be divided into two groups of two, and the transformer group includes two current transformers symmetrically arranged on both sides of the support plate and with opposite winding directions. In a transformer group, since the windings of the two current transformers are wound in opposite ways, they can cancel each other out the common-mode interference signals flowing through the corresponding voltage divider. At the same time, the winding directions of the two adjacent current transformers LH on the same side of the support plate are also opposite, so the two adjacent current transformers LH can also cancel out the common-mode interference signals flowing through the corresponding voltage branch, thereby improving the accuracy of the current signal values ​​measured by the multiple current transformers LH.

[0082] As a specific example, when the multiple current transformers LH include eight current transformers LH, these current transformers LH can be divided into four transformer groups, with the specific arrangement shown in Figures 7a and 7b. Figure 7a shows the winding arrangement of the four current transformers LH on one side of the support plate; Figure 7b shows the winding arrangement of the four current transformers LH on the other side of the support plate. a1 and b1 form one transformer group, and subsequent groupings are similar. This arrangement can reduce common-mode interference signals on multiple voltage branches, thereby improving the measurement accuracy of the current transformers.

[0083] The following uses a single-phase voltage shunt 123 as an example to illustrate the current signal processing process. Assuming that the current signal value flowing through the voltage input line of the shunt 123 is DL, and the shunt 123 outputs a total of n voltage branches, the following formula (1) can be obtained: DL = DL1 + DL2 + ... DLn (1)

[0084] Among them, DL1, DL2...DLn are the current signal values ​​flowing through each voltage branch DF1. At this time, the current signal collected by the first current transformer LH is DL1, and the secondary signal of the current transformer LH can be obtained by the following formula (2): DL1K=K1*DL1 (2)

[0085] Where DL1K is the secondary signal of the first current transformer LH, and K1 is the transformation ratio of the current transformer LH. Similarly, the secondary signal DL2K of the second current transformer LH can be equal to K2*DL2, where K2 is the transformation ratio of the second current transformer LH, and DL2 is the current signal collected by the second current transformer LH. The secondary signals of the remaining current transformers LH are similar. At this time, the output signal of the adder module 1221 can be obtained by the following formula (3): DLKJ=J*(DL1K+DL2K+…DLnK) (3)

[0086] Wherein, DLKJ is the output signal of the adder module 1221, DL1K, DL2K...DLnK are the secondary signals of n current transformers LH, and J is the linear proportional value of the adder ADD. The signal DLKJ is input to the metering module 130. At this time, if the current transformers LH of the same model and the same processing batch are selected, then the transformation ratios of these current transformers LH are the same. Then, according to the above formulas (1) and (3), the following formula (4) can be obtained: DLKJ = J*(DL1K+DL2K+...DKLn) = J*K1*(DL1+DL2+...DLn) = J*K1*DL (4)

[0087] DLKJ is the output signal of adder module 1221, K1 is the transformation ratio of current transformer LH, J is the linear scaling value of adder ADD, and DL is the current signal value flowing through the shunt voltage input line. The transformation ratio of current transformer LH and the linear scaling value of adder ADD are fixed and constrained by circuit component characteristics. Their values ​​can be measured during the calibration process during production and stored in metering module 130. Therefore, the signal DLKJ input to the metering module is linearly related to the current signal DL, allowing metering module 130 to measure the actual current value DL on the single-phase power supply line.

[0088] In some embodiments, as shown in Figure 8, the low-voltage distribution switch 100 also includes: an ADC sampling module 140, the ADC sampling module 140 is connected to multiple current detection units 122, and the ADC sampling module 140 is used to sample multiple current detection signals to obtain multiple current sampling signals, so as to perform power supply protection based on multiple current sampling signals.

[0089] Furthermore, the low-voltage distribution switch 100 also includes: a voltage detection module 150, multiple input ends of the voltage detection module 150 are connected to multiple output ends of the switch module 110 and the neutral line input end of the low-voltage distribution switch 100, the neutral line input end is suitable for being connected to the neutral line of the power supply line, and the voltage detection module 150 is used to detect the voltage of each phase power supply line in the multi-phase power supply line to obtain multiple voltage detection signals; the metering module 130 is also connected to the voltage detection module 150, and the metering module 130 is also used to sample multiple voltage detection signals, and calculate multiple first voltages based on the multiple voltage detection signals, and determine first electric energy metering data based on multiple first currents and multiple first voltages; the ADC sampling module 140 is also connected to the voltage detection module 150, and the ADC sampling module 140 is also used to sample multiple voltage detection signals to obtain multiple voltage sampling signals, so as to perform power supply protection based on multiple current sampling signals and multiple voltage sampling signals.

[0090] Specifically, the voltage detection module 150 can be a voltage detection device such as a three-phase voltage transformer. As shown in FIG8 , the voltage detection module 150 is connected to the multiple output terminals of the switch module 110 and the neutral line input terminal of the low-voltage distribution switch 100 to detect the voltage of each phase of the multi-phase power supply line and obtain multiple voltage detection signals. At this time, the metering module 130 can sample the multiple voltage detection signals to obtain multiple first voltages, where the first voltage refers to the voltage value of each phase of the power supply line. Subsequently, the metering module 130 can calculate the corresponding first electric energy metering data based on the determined multiple first currents and first voltages, thereby implementing the electric energy metering function.

[0091] Continuing with FIG8 , the ADC sampling module 140 can be connected to multiple current detection units 122 and voltage detection modules 150 to sample multiple current detection signals and multiple voltage detection signals to obtain multiple current sampling signals and multiple voltage sampling signals. These sampling signals can provide data support for power supply protection of the low-voltage distribution switch 100, thereby improving the safety of the low-voltage distribution switch 100. Power supply protection can include overvoltage protection, overcurrent protection, islanding protection, etc. The specific protection principles will not be elaborated here.

[0092] Optionally, the ADC sampling module 140 may use an AD7606 chip, which has a 16-bit encoding bit and a sampling rate of up to 100k, and can meet various sampling requirements of the ADC sampling module implemented in the present invention.

[0093] In some embodiments, the low-voltage distribution switch 100 further includes: a main control module 160, the main control module 160 being connected to the metering module 130 and the ADC sampling module 140, wherein the main control module 160 is configured to, when the metering module 130 is not failed, obtain first electric energy metering data from the metering module 130; when the metering module 130 is failed, obtain multiple current sampling signals and multiple voltage sampling signals from the ADC sampling module 140, and determine the first electric energy metering data based on the multiple current sampling signals and the multiple voltage sampling signals; the main control module 160 is further configured to, when the ADC sampling module 140 is not failed, obtain multiple current sampling signals and multiple voltage sampling signals from the ADC sampling module 140 so as to perform power supply protection based on the multiple current sampling signals and the multiple voltage sampling signals; when the ADC sampling module 140 is failed, obtain multiple first currents and multiple first voltages from the metering module 130 so as to perform power supply protection based on the multiple first currents and multiple first voltages.

[0094] Specifically, as shown in FIG8 , when both the metering module 130 and the ADC sampling module 140 are functioning normally, the main control module 160 obtains first electric energy metering data from the metering module 130 to implement the electric energy metering function, and obtains multiple current sampling signals and multiple voltage sampling signals from the ADC sampling module 140, and analyzes the multiple current sampling signals and multiple voltage sampling signals to perform power supply protection for the low-voltage distribution switch 100. When the metering module 130 fails, the main control module 160 can obtain multiple current sampling signals and multiple voltage sampling signals from the ADC sampling module 140 and determine the first electric energy metering data based on the multiple current sampling signals and multiple voltage sampling signals. When the ADC sampling module 140 fails, the main control module 160 can obtain multiple first currents and multiple first voltages from the metering module 130 to perform power supply protection based on the multiple first currents and multiple first voltages.

[0095] In the aforementioned embodiment, when the ADC module 140 fails, the power supply protection function of the low-voltage power distribution switch 100 fails. When the metering module 130 fails, the electric energy metering function of the low-voltage power distribution switch 100 fails, thereby posing a safety hazard or functional failure to the low-voltage power distribution switch 100. In the embodiment of the present invention, when either the metering module 130 or the ADC sampling module 140 fails, the main control module 160 can implement both the electric energy metering and power supply protection functions based on the voltage and current signals collected by the normal modules. This prevents maintenance personnel from losing a function of the low-voltage power supply switch 100 when they arrive at the site for repair or replacement, thereby preventing the low-voltage power supply switch 100 from posing a safety hazard due to the loss of a function. Therefore, the low-voltage power distribution switch of the embodiment of the present invention has a higher reliability.

[0096] Therefore, by setting up a main control module in the low-voltage distribution switch, when one of the metering module or the ADC sampling module fails, the main control module can enable the normal module to simultaneously realize the power metering and power supply protection functions, so that the metering module and the ADC sampling module can back up each other, thereby effectively improving the reliability of the low-voltage distribution switch.

[0097] In some embodiments, the main control module 160 is further configured to obtain a plurality of voltage sampling signals from the ADC sampling module 140 and a plurality of first voltages from the metering module 130, and to determine whether the metering module 130 and the ADC sampling module 140 have failed based on the plurality of voltage sampling signals and the plurality of first voltages.

[0098] Furthermore, the main control module 160 is configured to calculate a plurality of second voltages based on the plurality of voltage sampling signals, obtain a voltage difference between each first voltage and the corresponding second voltage to obtain a plurality of voltage difference values, and determine whether the metering module 130 and the ADC sampling module 140 have failed based on the plurality of first voltages and the plurality of second voltages when any voltage difference value among the plurality of voltage difference values ​​is greater than or equal to a first preset voltage difference threshold.

[0099] Specifically, the first preset voltage difference threshold represents the maximum voltage difference between the metering module 130 and the ADC sampling module 140 due to measurement error. For example, the first preset voltage difference threshold may be 2%. When both the metering module 130 and the ADC sampling module 140 are operating normally, the multiple second voltages calculated by the main control module 160 based on the voltage sampling signals should be the same as or have a small difference from the corresponding first voltage. Therefore, the main control module 160 can obtain multiple voltage differences between each first voltage and the corresponding second voltage. If any of the multiple voltage differences is greater than or equal to the first preset voltage difference threshold, it determines that at least one of the metering module 130 and the ADC sampling module 140 has failed. In this case, the multiple voltage sampling signals and the multiple first voltages can be further analyzed to determine whether the metering module 130 and the ADC sampling module 140 have failed, enabling the main control module to implement a mutual backup function for the metering module and the ADC sampling module.

[0100] In some embodiments, the main control module 160 is configured to determine whether the metering module 130 and the ADC sampling module 140 have failed based on at least one of a DC component, an amplitude, a waveform distortion, a power, a power factor, a frequency, and a phase sequence corresponding to the plurality of first voltages and the plurality of second voltages.

[0101] Specifically, when it is determined that at least one of the metering module 130 and the ADC sampling module 140 has failed, the main control module 160 can determine the source of the failure, that is, by judging whether the multiple first voltages and the multiple second voltages meet preset requirements in terms of DC component, amplitude, waveform distortion, power, power factor, frequency and phase sequence, to determine whether the metering module 130 and the ADC sampling module 140 have failed, so that the main control module can enable normal modules to simultaneously realize the power metering and power supply protection functions.

[0102] Furthermore, the main control module 160 is configured to determine that the metering module 130 is inoperative when the DC component of the first voltage is greater than a preset DC component; and to determine that the ADC sampling module 140 is inoperative when the DC component of the second voltage is greater than a preset DC component.

[0103] Specifically, the preset DC component is used to distinguish whether the DC component in the first and second currents is zero. Since the first and second voltages are normally AC signals, their DC component should be zero. Therefore, if the DC component of the first voltage is greater than the preset DC component, metering module 130 is determined to be faulty; and if the DC component of the second voltage is greater than the preset DC component, ADC sampling module 140 is determined to be faulty. This allows for the determination of faults in both the metering module and the ADC sampling module based on the DC components of the first and second voltages.

[0104] Furthermore, the main control module 160 is configured to determine that the metering module 130 is invalid when the amplitude of the first voltage is not within the preset amplitude range; and to determine that the ADC sampling module 140 is invalid when the amplitude of the second voltage is not within the preset amplitude range.

[0105] Specifically, the preset amplitude range is determined based on the normal effective voltage range of the multi-phase power supply line. For example, when the multi-phase power supply line is a 220V three-phase AC power supply, the preset amplitude range is 120V to 320V. Therefore, when the amplitude of the first voltage or the amplitude of the second voltage is not within the preset amplitude range, it can be determined that the corresponding metering module or ADC sampling module has failed, thereby implementing the function of determining whether the metering module and ADC sampling module have failed based on the amplitudes of the first voltage and the second voltage.

[0106] Furthermore, the main control module 160 is configured to determine that the metering module 130 has failed when the waveform distortion of the first voltage is greater than a first preset distortion, or when the waveform distortion of the first voltage is greater than the waveform distortion of the second voltage, and the difference between the waveform distortion of the first voltage and the waveform distortion of the second voltage is greater than a second preset distortion; and to determine that the ADC sampling module 140 has failed when the waveform distortion of the second voltage is greater than the first preset distortion, or when the waveform distortion of the second voltage is greater than the waveform distortion of the first voltage, and the difference between the waveform distortion of the second voltage and the waveform distortion of the first voltage is greater than a second preset distortion.

[0107] Specifically, the first preset distortion level is the maximum possible distortion level of the first and second voltages, taking into account factors such as line transmission loss and noise interference. For example, the first preset distortion level can be 40%. When metering module 130 and ADC sampling module 140 are functioning properly, the waveform distortion levels of the first and second voltages should be less than the first preset distortion level. Therefore, if the waveform distortion level of the first voltage exceeds the first preset distortion level, metering module 130 can be determined to be faulty; and if the waveform distortion level of the second voltage exceeds the first preset distortion level, ADC sampling module 140 can be determined to be faulty.

[0108] The second preset distortion factor represents the maximum possible difference in distortion between the first and second voltages after accounting for sampling errors. For example, the second preset distortion factor can be 10%. Since metering module 130 and ADC sampling module 140 operate in the same sampling environment, the waveform distortions of the first and second voltages should be similar. That is, the difference between their waveform distortions should be less than the second preset distortion factor. If the difference between the waveform distortions exceeds the second preset distortion factor, the module corresponding to the voltage with the greater waveform distortion can be determined to be faulty. Therefore, when the waveform distortion of the first voltage is greater than the waveform distortion of the second voltage, and the difference between the waveform distortions of the first and second voltages is greater than the second preset distortion factor, metering module 130 can be determined to be faulty. Alternatively, when the waveform distortion of the second voltage is greater than the waveform distortion of the first voltage, and the difference between the waveform distortions of the second voltage and the first voltage is greater than the second preset distortion factor, ADC sampling module 140 can be determined to be faulty. This enables the determination of faults in both the metering module and the ADC sampling module based on the waveforms of the first and second voltages.

[0109] Furthermore, the main control module 160 is configured to determine that the metering module 130 is invalid when the first power corresponding to the first voltage is negative; and to determine that the ADC sampling module 140 is invalid when the second power corresponding to the second voltage is negative.

[0110] Specifically, since the voltage and current are in the same direction during normal power supply, the power calculated from the first voltage and the second voltage is also a positive number. Therefore, when the first power corresponding to the first voltage is negative, it means that the first voltage and the corresponding first current are opposite, and the metering module 130 can be determined to be faulty. Similarly, when the second power corresponding to the second voltage is negative, the ADC sampling module 140 can be determined to be faulty. In this way, the function of determining whether the metering module and the ADC sampling module are faulty based on the power corresponding to the first voltage and the second voltage is realized.

[0111] In some embodiments, the main control module 160 is configured to determine that the metering module 130 has failed when the first power factor corresponding to the first voltage is less than a preset power factor; and to determine that the ADC sampling module 140 has failed when the second power factor corresponding to the second voltage is less than a preset power factor.

[0112] Specifically, the preset power factor refers to the lowest value of the power factor of the first voltage and the second voltage when the low-voltage distribution switch 100 is normal. For example, the preset power factor can be 0.6. Therefore, when the first power factor corresponding to the first voltage or the second power factor corresponding to the second voltage is less than the preset power factor, it can be determined that the corresponding metering module 130 or ADC sampling module 140 has failed. In this way, the function of determining whether the metering module and the ADC sampling module have failed based on the first power factor corresponding to the first voltage and the second voltage is realized.

[0113] Furthermore, the main control module 160 is configured to determine that the ADC sampling module 140 has failed when the frequency difference between the frequency of the first voltage and the preset frequency is smaller than the frequency difference between the frequency of the second voltage and the preset frequency, and the frequency difference between the frequency of the second voltage and the frequency of the first voltage is larger than the preset frequency difference; and to determine that the metering module 130 has failed when the frequency difference between the frequency of the second voltage and the preset frequency is smaller than the frequency difference between the frequency of the first voltage and the preset frequency, and the frequency difference between the frequency of the first voltage and the frequency of the second voltage is larger than the preset frequency difference.

[0114] Specifically, the preset frequency refers to the operating frequency of the multi-phase power supply line. For example, the preset frequency may be 50 Hz. The preset frequency difference refers to the maximum possible frequency difference between the first voltage or the second voltage frequency due to measurement error. For example, when the frequency measurement accuracy is 0.01 Hz, the preset frequency difference may be 0.5 Hz. When the metering module 130 or the ADC sampling module 140 is functioning properly, the first voltage or the second voltage frequency should be close to the preset frequency, and the difference between the first voltage frequency and the second voltage frequency should be less than the preset frequency difference. Therefore, when the frequency difference between the frequency of the first voltage and the preset frequency is less than the frequency difference between the frequency of the second voltage and the preset frequency, it means that the frequency of the first voltage is closer to the preset frequency. At this time, if the frequency difference between the frequency of the second voltage and the frequency of the first voltage is greater than the preset frequency difference, it means that the ADC sampling module 140 corresponding to the second voltage has a sampling error problem. At this time, it can be determined that the ADC sampling module 140 has failed. Similarly, when the frequency difference between the frequency of the second voltage and the preset frequency is less than the frequency difference between the frequency of the first voltage and the preset frequency, it means that the frequency of the second voltage is closer to the preset frequency. At this time, if the frequency difference between the frequency of the first voltage and the frequency of the second voltage is greater than the preset frequency difference, it can be determined that the metering module 130 has failed. In this way, the function of determining whether the metering module and the ADC sampling module have failed based on the first voltage and the second voltage frequencies is realized.

[0115] Furthermore, the main control module 160 is configured to determine that the metering module 130 is inoperative when the phase sequence of the plurality of first voltages is different from the preset phase sequence; and to determine that the ADC sampling module 140 is inoperative when the phase sequence of the plurality of second voltages is different from the preset phase sequence.

[0116] Specifically, the preset phase sequence refers to the phase sequence of a multi-phase power supply circuit. For example, when the multi-phase power supply circuit is a three-phase 220V power supply, the phase sequence of phases A, B, and C should be such that the voltage of phase A leads the voltage of phase B by 120 degrees, and the voltage of phase B leads the voltage of phase C by 120 degrees. Therefore, when the phase sequence determined by the multiple first voltages differs from the preset phase sequence, it indicates that the metering module 130 has failed. Similarly, when the phase sequence determined by the multiple second voltages differs from the preset phase sequence, it indicates that the metering module 130 has failed. This implements the function of determining whether the metering module and ADC sampling module have failed based on the corresponding phase sequence of the first and second voltages.

[0117] Optionally, when it is determined that there is a failed module in the metering module 130 and the ADC sampling module 140, and the above-mentioned DC component, amplitude, waveform distortion, power, power factor, frequency, and phase sequence methods cannot determine which of the metering module 130 and the ADC sampling module 140 has failed, the metering module 130 can be directly determined to have failed, because a large amount of empirical data shows that the metering module 130 is more likely to fail.

[0118] In some embodiments, a first frequency at which the main control module 160 obtains the multiple first currents and multiple first voltages from the metering module 130 is lower than a second frequency at which the main control module 160 obtains the multiple current sampling signals and the multiple voltage sampling signals from the ADC sampling module 140. The main control module 160 is further configured to perform power supply protection based on the multiple first currents, the multiple first voltages, and the first frequency when the ADC sampling module 140 fails.

[0119] Specifically, since the metering module 130 is primarily used for electric energy metering and has lower real-time requirements than the power supply protection function, the first frequency at which the main control module 160 obtains the multiple first currents and multiple first voltages from the metering module 130 may be lower than the second frequency at which the main control module 160 obtains the multiple current sampling signals and multiple voltage sampling signals from the ADC sampling module 140. For example, the period corresponding to the first frequency is typically greater than 0.8 seconds, while the period corresponding to the second frequency is typically in the millisecond range. Therefore, when the ADC sampling module 140 fails, when the main control module 160 uses the multiple first voltages and first currents from the metering module 130 to perform power supply protection, such as overvoltage protection, it is necessary to wait until the first voltage is greater than the overvoltage threshold and persists for a predetermined period of time before determining that the multi-phase power supply line is overvoltage. Since overvoltage protection requires the high sampling frequency of the ADC sampling module 140, when the main control module 160 performs power supply protection, it is necessary to simultaneously consider the first frequency to implement the power supply protection function, thereby improving the power supply protection function for the multi-phase power supply line.

[0120] Taking overvoltage protection as an example, assuming the period corresponding to the first frequency is 1s, when the preset duration of the overvoltage protection is less than 1s, the main control module 160 will perform overvoltage protection on the multi-phase power supply line when it detects that the first voltage is higher than the preset voltage threshold, thereby ensuring the safety of the multi-phase power supply line. If the preset duration of the overvoltage protection is greater than 1s, the main control module 160 will not perform overvoltage protection on the multi-phase power supply line again until it detects that the first voltage is higher than the preset voltage threshold for the preset duration, thereby avoiding erroneous overvoltage protection.

[0121] Optionally, when the metering module fails, the main control module 160 needs to calculate the corresponding active power and reactive power based on the multiple voltage sampling signals and current sampling signals sampled by the ADC sampling module 140, and determine the corresponding sampling time based on the second frequency; then, the active power is accumulated according to the sampling time to obtain the active electric energy, and the reactive power is accumulated according to the sampling time to obtain the reactive electric energy, thereby realizing the electric energy metering function through the ADC sampling module.

[0122] In some embodiments, the main control module 160 is also used to correct multiple first voltages and multiple first currents based on the ratio of the second voltage to the first voltage when each voltage difference in the multiple voltage differences is less than a first preset voltage difference threshold and greater than a second preset voltage difference threshold, wherein the second preset voltage difference threshold is less than the first preset voltage difference threshold.

[0123] Specifically, the first preset voltage difference threshold is used to determine whether there is an excessive error between metering module 130 and ADC sampling module 140; the second preset voltage difference threshold is used to determine whether there is an error between the first voltage and the second voltage. Therefore, the second preset voltage difference threshold is smaller than the first preset voltage difference threshold. For example, the first preset voltage difference threshold may be 2%, and the second preset voltage difference threshold may be 0.5%. When each voltage difference between the plurality of first voltages and the corresponding second voltage is smaller than the first preset voltage difference threshold and larger than the second preset voltage difference threshold, it indicates that metering module 130 and ADC sampling module 140 are both operating normally, but with some error. Furthermore, because the temperature coefficient of the signal processing channel of ADC sampling module 140 is relatively small, the sampling error of ADC sampling module 140 is also relatively small, resulting in more accurate sampled data. Therefore, at this time, multiple first voltages and multiple first currents can be corrected based on the ratio of the second voltage to the first voltage, that is, the sampled first voltage and first current are multiplied by the ratio of the second voltage to the first voltage as the final first voltage and first current, and the final first voltage and first current are used for electric energy measurement. This method can improve the accuracy of the first voltage and first current sampled by the metering chip, thereby effectively improving the accuracy of the electric energy metering function.

[0124] In some embodiments, the main control module 160 is further configured to analyze and process the first electric energy metering data to obtain second electric energy metering data.

[0125] Specifically, the second electric energy metering data includes data such as accumulated electric energy, time-divided electric energy, and daily settled electric energy. After the metering module 130 determines the first electric energy metering data, the main control module 160 can also obtain the second electric energy metering data based on the first electric energy metering data for subsequent statistical analysis of the electric energy metering data, including electric energy accumulation, freezing, and four-quadrant analysis, thereby improving the convenience of the electric energy metering function.

[0126] In some embodiments, as shown in Figure 8, the low-voltage distribution switch 100 also includes: a protection control module 170, which is connected to the switch module 110 and is used to control the switch module 110; the main control module 160 is also connected to the protection control module 170, and the main control module 160 is also used to generate a protection signal based on multiple current sampling signals and multiple voltage sampling signals, or based on multiple first currents and multiple first voltages, and send it to the protection control module 170, so that the protection control module 170 controls the switch module 110 to disconnect based on the protection signal for power supply protection.

[0127] Specifically, when the main control module 160 determines that the multi-phase power supply line is in a dangerous power supply condition such as overvoltage or overcurrent based on the sampling data of the ADC sampling module 140 or the metering module 130, the main control module 160 generates a protection signal and sends it to the protection control module 170. Subsequently, the protection control module 170 controls the switch module 110 to disconnect, thereby achieving power supply protection for the multi-phase power supply line.

[0128] In some embodiments, as shown in Figure 8, the low-voltage distribution switch 100 also includes: a status acquisition module 180, the status acquisition module 180 is connected to the switch module 110 and the main control module 160, and the status acquisition module 180 is used to obtain the switch status and / or power supply protection mode of the switch module 110 and send it to the main control module 160.

[0129] Specifically, the status acquisition module 180 is used to obtain various status change signals of the low-voltage distribution switch 100 and send them to the main control module 160 so that the main control module 160 can control the low-voltage distribution switch, where the status change signal may include the on / off status of the switch module 110, the manual and automatic status of the power supply protection module, etc.

[0130] In some embodiments, as shown in reference Figure 9, the low-voltage distribution switch 100 also includes: an agent module 190 and an isolation module 1100, the agent module 190 is connected to the metering module 130, the ADC sampling module 140, the protection control module 170, the status acquisition module 180 and the isolation module 1100, and the isolation module 1100 is connected to the main control module 160, wherein the agent module 190 is used to obtain first electric energy metering data, multiple first voltages, multiple first currents, multiple voltage sampling signals, multiple current sampling signals, and switch status and / or power supply protection mode, and send them to the main control module 160 through the isolation module 1100, and receive the protection signal through the isolation module and send it to the protection control module.

[0131] Specifically, as shown in FIG9 , in a low-voltage power distribution switch 100 , the data acquisition and calculation functions within the metering module 130, ADC sampling module 140, protection control module 170, and status acquisition module 180 are simple, regular, and real-time. Therefore, a low-frequency clock can be used to improve electromagnetic interference immunity. Furthermore, these modules need to carry high voltages, large currents, or strong electromagnetic fields, and can be installed close to sampling devices to improve data communication reliability. These modules can be divided into a primary section, and operators must implement isolation measures when accessing these modules. In the low-voltage power distribution switch 100 , the main control module 160 is the computing core and must perform complex computational analysis tasks. Therefore, the operating clock frequency is relatively high. Furthermore, the main control module 160 also handles data management and storage, placing high security requirements on the main control module 160. Furthermore, the main control module 160 is typically powered by a low voltage and can be plugged and unplugged while powered on, thus dividing the main control module 160 into a secondary section. From the above, it can be seen that the working environment requirements and operator contact safety requirements of the primary and secondary parts in the low-voltage distribution switch 100 are inconsistent. Therefore, an isolation module 1100 can be set between the two parts to simultaneously meet the working environment requirements of both and protect the operating safety of personnel, as shown in Figure 10.

[0132] For example, the NSiP8842 chip (hereinafter referred to as the NS chip) shown in FIG11 can be used as the isolation module 1100 to implement the isolation function of the high-frequency operation part and the low-frequency operation part. The NS chip is a digital isolation chip with an integrated isolated DC / DC power supply, a communication rate of up to 150 Mbps, a built-in isolation transformer, and an isolation voltage of up to 4500 volts, which can meet the isolated communication requirements of the embodiment of the present invention. Referring to FIG11, pins 1 and 7 of the NS chip are the first DC power supply VDD1, which is used to power the primary part of the NS chip, and pins 2 and 8 are the first ground terminal GND1 corresponding to the first DC power supply VDD1; pins 4 and 5 are the transmitting port TXD1 and the receiving port RXD1 of the primary part; pins 10 and 16 are the second preset power supply VDD2, which is used to power the secondary part, and the second preset power supply VDD2 can be coupled from the first preset power supply VDD1; pins 9 and 15 are the second ground terminal GND2 corresponding to the second preset power supply VDD2; pins 12 and 13 are the transmitting port TXD2 and the receiving port RXD2 of the secondary part, respectively. As can be seen, the NS can achieve the isolation function of two communication lines. However, in the embodiment of the present invention, as shown in Figure 10, the metering module 130 and the ADC sampling module 140 need to communicate with the main control module 160 via an SPI (serial peripheral interface) interface. Each SPI interface requires four communication lines for communication. At the same time, the protection control module 170 and the status acquisition module 180 require a total of four GPIO (general purpose input ouput) ports to communicate with the main control module 160. Therefore, if the main control module 160 directly communicates with the low-frequency operating modules such as the metering module 130 through the isolation module 1100, at least 12 communication lines are required, and therefore six NS chips are required to achieve the isolation function. This will result in high cost and multiple wiring harnesses for the low-voltage distribution switch 100, which is not conducive to the design of the isolation structure. Therefore, referring to Figure 9, the low-voltage distribution switch 100 of an embodiment of the present invention also includes an agent module 190, which is connected to the metering module 130 and the ADC sampling module 140 through the SPI interface, and is connected to the protection control module 170 and the status acquisition module 180 through the GPIO port.At the same time, the proxy module 190 is also connected to the main control module 160 via the isolation module 1100. Since most of the partially collected first power metering data, multiple first voltages, multiple first currents, multiple voltage sampling signals, multiple current sampling signals, and switch status and / or power protection mode data do not require high real-time communication, low-speed communication can meet these requirements. Therefore, the low-speed communication data of these parallel interfaces can be packaged into high-speed serial data and transmitted via UART (universal asynchronous receiver transmitter) communication to save interfaces. For example, the proxy module 190 can communicate with the main control module 160 via two communication lines via UART communication. In this case, the proxy module 190 only needs two communication lines to meet all the communication needs of the main control module 160. Therefore, only one NS chip can be used as the isolation module 1100, as shown in Figure 11. As shown in reference figure 11, the proxy module 190 and the isolation module 1100 at this time can not only realize the isolated communication function of the primary part and the secondary part, but also ensure the integrity of the communication data, thereby reducing the setting of isolation devices in the isolation module and reducing the cost and design difficulty of the isolation structure.

[0133] Therefore, by setting up a proxy module and an isolation module in the low-voltage distribution switch, the isolation communication function of the internal primary and secondary parts can be realized, while saving the setting of isolation devices, which is beneficial to the design of the electrical isolation structure and improving the safety of operators.

[0134] Furthermore, the priority of the proxy module in sending the data of the metering module 130 is lower than the priority of sending the data of the ADC sampling module 140 and higher than the priority of sending the data of the status acquisition module.

[0135] Specifically, the proxy module's transmission priority for data from the metering module 130, the ADC sampling module 140, and the status acquisition module can be determined based on the data's real-time requirements and impact on safety. Data from the ADC sampling module 140 is primarily used to provide power protection to the multi-phase power supply line for the main control module 160, placing high demands on real-time performance and safety. Therefore, data from the ADC sampling module 140 has the highest priority. Furthermore, data from the metering module 130 is also used to protect the multi-phase power supply line in the event of a failure of the ADC sampling module 140. Therefore, data from the metering module 130 has a lower priority than data from the metering module 130, but a higher priority than data from the status acquisition module 180. Finally, data from the status acquisition module 180 primarily includes switch status and / or power protection mode data. These data do not require high real-time performance and have little impact on the safety of the multi-phase power supply line. Therefore, data from the status acquisition module 180 can be sent with the lowest priority.

[0136] As a specific example, when the multi-phase power supply line is a three-phase four-wire 220V power supply, the main control module 160 and the agent module 190 can communicate in the following manner:

[0137] In proxy module 190, the proxy module 190 periodically and continuously reads the sampled data from ADC module 130 via the SPI interface. Within each power frequency cycle of the multi-phase power supply line, the voltage / current signals are uniformly sampled at 128 points, at a sampling frequency of 6400 Hz. Within each sampling cycle, whenever the 64th point (approximately 10 milliseconds) is sampled, the proxy module 190 transmits the sampled voltage and current signals (hereinafter referred to as sampled data) to main control module 160. Furthermore, the proxy module 190 communicates with the metering module 130 at one-second intervals to obtain the first voltage and first current sampled by the metering module 130 (hereinafter referred to as metering data). Furthermore, when the proxy module 190 is not transmitting sampled data, the metering data is transmitted to the main control module. Finally, when the low-voltage distribution switch 100 changes state, the state change data is first buffered. If the proxy module 190 is not sending data, it sends the state change data. If the proxy module 190 is sending data, it sends the state change data to the main control module 160 after completing the data transmission. Furthermore, each of the aforementioned data transmissions cannot be interrupted during transmission to ensure reliable data transmission.

[0138] In the main control module 160, every time it receives 64 samples of data, it caches them and calculates the current RMS voltage, current, and frequency based on these samples and the previous set of 64 samples. It then performs overvoltage, overcurrent, and overfrequency analysis. If an overvoltage or overcurrent fault is detected, the main control module 160 issues a control command to the proxy module 190. Upon receiving the control command, the proxy module 190 immediately activates the protection control module 170 to perform the corresponding action, thereby implementing power supply protection for the multi-phase power supply line. Furthermore, when the main control module 160 receives a set of metering data, it performs an energy statistical analysis, including energy accumulation, freezing, and four-quadrant analysis.

[0139] In the communication method of the embodiment of the present invention, the communication rate between the agent module 190 and the main control module 160 can be set to 2 Mbps. In this case, the communication time for every 64 samples is 64*16*6 / 2M≈3 milliseconds (64 represents the number of samples, 16 represents that each signal in each sample is 16 bits, 6 represents that each sample includes three voltage signals and three current signals, and 2M represents the current communication rate). As can be seen from the above, the agent module 190 of the embodiment of the present invention transmits sample data every 10 milliseconds. Therefore, after each sample data transmission, the agent module 190 has 7 milliseconds of idle time for transmitting metering data or state change data. Assuming that the metering data includes eight types of data, namely, forward active electric energy value, reverse active electric energy value, forward reactive electric energy value, reverse reactive electric energy value, voltage value, current value, active power and reactive power, the communication time of the metering data is: 8*24*3 / 2M=0.576 milliseconds (8 represents 8 quantities of data per phase, 24 means that each quantity is 24 bits, 3 represents three-phase voltage, and 2M represents the current communication rate). Similarly, assuming that the state change data includes the change source identifier, the change state, and the change time, wherein the change source identifier and the change state each require 1 byte, and the change time requires 4 bytes, then the communication time of the state change data is 6*8 / 2M=0.024 milliseconds (6 means that the state change data includes 6 bytes, 8 means that each byte includes 8 bits, and 2M means the current communication rate). It can be seen that 7 milliseconds is sufficient to send the above-mentioned metering data and state change data. At the same time, if the state of the low-voltage distribution switch 100 changes when sending the sampling data, the proxy module 190 will send the state change data to the main control module 180 after a maximum delay of 3 milliseconds. This time will not cause a control error of the low-voltage distribution switch 100.

[0140] In addition, in the communication method of the embodiment of the present invention, the clock of the proxy module 190 is set by the main control module 160 to ensure the accuracy of the time stamp of the sampled data, metering data, and state change data. The specific method is as follows: a microsecond timer is started in the proxy module 190, and the main control module 160 sends a clock setting frame (carrying the time T of the main control module). The proxy module 190 records the time value T1 of the microsecond timer at the beginning of the frame when it receives the frame, and records the time value T2 of the microsecond timer at the end of the frame when it receives the frame. Then, the proxy module sets its own clock in the manner of T+T2-T1. The main control module 160 can set the clock of the proxy module once every 1 second and set it at 0.5 seconds per second, thereby ensuring that the clocks of the main control module and the proxy module are synchronized, avoiding the misalignment of the second value or the second value when the time is carried, thereby improving the reliability of the low-voltage distribution switch.

[0141] In some embodiments, as shown in FIG9 , the low-voltage power distribution switch 100 further includes a first power module 1110 and a second power module 1120. The input end of the first power module 1110 is connected to multiple input ends of the switch module 110, the output end of the first power module 1110 is connected to the input end of the second power module 1120, and the output end of the second power module 1120 is connected to the isolation module 1100. The first power module 1110 is configured to convert a first power supply voltage provided by a multi-phase power supply line into a second power supply voltage, and the second power module 1120 is configured to convert the second power supply voltage into a third power supply voltage and provide it to the isolation module 1100. Power is then supplied to the proxy module 190 and the main control module 160 via the isolation module 1100.

[0142] Specifically, the first power module 1110 can be a rectifier and step-down circuit, primarily configured to convert alternating current (AC) at a first supply voltage on a multi-phase power supply line into direct current (DC) at a second supply voltage, and then provide the DC power to the second power module 1120. The second power module 1120 can be a step-down circuit, primarily configured to step down the second supply voltage to a third supply voltage of a preset voltage value, thereby powering the isolation module 1100 and, through the isolation module 1100, powering the proxy module 190 and the main control module 160. For example, when the isolation module 1100 includes the aforementioned NS chip, the preset voltage value is 5V. In this case, the first power module 1110 and the second power module 1120 can provide a stable 5V DC power supply to the isolation module.

[0143] Optionally, as shown in FIG9 , the low-voltage distribution switch 100 may further include a human-computer interaction module 1130 and a communication module 1140, wherein the human-computer interaction module 1130 can provide a human-computer interaction service for the user so that the user can conveniently perform parameter debugging, configuration, detection and other functions on the main control module 160; the communication module 1140 can enable the main control module 160 to have remote communication capabilities, so that the user can exchange data with the main control module 160 through remote communication, and the main control module 160 can also implement an online upgrade function through the communication module 1140, thereby further optimizing the low-voltage distribution switch 100. In the above embodiment, the main control module 160, the protection control module 170, the status acquisition module 180, the agent module 190, the human-computer interaction module 1130 and the communication module 1140 can respectively be one or more processors, controllers or chips with a communication interface capable of implementing a communication protocol, and if necessary, can also include a memory and related interfaces, a system transmission bus, etc.; the processor, controller or chip executes program-related code to implement the corresponding function. Alternatively, an alternative solution is for the main control module 160, protection control module 170, status acquisition module 180, agent module 190, human-computer interaction module 1130, and communication module 1140 to share an integrated chip or a processor, controller, memory, or other device. The shared processor, controller, or chip executes program-related code to implement corresponding functions.

[0144] In summary, according to the low-voltage distribution switch of the embodiment of the present invention, by providing multiple current detection modules and metering modules, and each current detection module includes multiple current detection units and multiple current branches connected in parallel, when the low-voltage distribution switch is working normally, the multiple current branches of each current detection module can achieve the effect of shunting, thereby improving the accuracy and linearity of the multiple branch current detection signals obtained by the current detection unit, thereby improving the linearity and accuracy of the electric energy metering function; at the same time, by providing a voltage sampling module, an ADC sampling module and a main control module in the low-voltage distribution switch, the main control module can obtain A The DC sampling module and metering module sample the voltage and current of the power supply line through the current detection module and the voltage detection module and perform corresponding analysis, thereby realizing the mutual backup and mutual correction functions of the power supply protection and electric energy metering functions, and improving the accuracy and reliability of the power supply protection and electric energy metering functions; in addition, by setting the proxy module and the isolation module in the low-voltage distribution switch and reasonably dividing the functional modules, the electrical isolation and data interaction of the primary and secondary parts are achieved with a simple isolation structure, thereby saving the cost of the low-voltage power supply switch, ensuring the safety of personnel operation, and realizing comprehensive optimization of the low-voltage distribution switch.

[0145] Corresponding to the above embodiment, an embodiment of the present invention further provides a power supply device. Referring to FIG. 12 , the power supply device 1000 includes the aforementioned low-voltage distribution switch 100 .

[0146] The power supply equipment according to the embodiment of the present invention can realize the electric energy metering function with high linearity and accuracy through the aforementioned low-voltage distribution switch, and can also realize the mutual backup and mutual correction functions of power supply protection and electric energy metering functions. In addition, it can also realize the isolated communication function of the low-voltage part and the high-voltage part, thereby realizing the optimization of the power supply equipment.

[0147] It should be noted that the logic and / or steps represented in the flowcharts or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing the logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (e.g., a computer-based system, a system including a processor, or other system that can fetch and execute instructions from an instruction execution system, apparatus, or device). For purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport a program for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (non-exhaustive list) of computer-readable media include the following: an electrical connection with one or more wires (electronic device), a portable computer disk cartridge (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and programmable read-only memory (EPROM or flash memory), fiber optic devices, and portable compact disc read-only memory (CDROM). Furthermore, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing it in another suitable manner if necessary, and then storing it in a computer memory.

[0148] It should be understood that various parts of the present invention can be implemented using hardware, software, firmware, or a combination thereof. In the above-described embodiments, multiple steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented using hardware, as in another embodiment, any one of the following technologies known in the art or a combination thereof can be used: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application-specific integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0149] Throughout this specification, references to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0150] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0151] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediate medium; internal communication between two components, or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0152] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A low voltage power distribution switch, characterized in that: include: A switch module, wherein the multiple input terminals of the switch module are suitable for correspondingly connecting to multi-phase power supply lines as voltage input terminals of the low-voltage power distribution switch, and the switch module is used to connect or disconnect the multi-phase power supply lines; A plurality of current detection modules, wherein the input ends of the plurality of current detection modules are correspondingly connected to the plurality of output ends of the switch module, and the output ends of the plurality of current detection modules are suitable for correspondingly connecting to the multi-phase power supply lines as the voltage outlet ends of the low-voltage power distribution switch, and each of the current detection modules comprises a plurality of current branches and a current detection unit, and the plurality of current branches are connected in parallel between the input end and the output end of the corresponding current detection module, and the current detection unit is used to detect the current of each current branch to obtain a plurality of branch current detection signals, and obtain the current detection signal of the corresponding phase power supply line based on the plurality of branch current detection signals; A voltage detection module, wherein multiple input terminals of the voltage detection module are connected to multiple output terminals of the switch module and a neutral line inlet terminal of the low-voltage power distribution switch, the neutral line inlet terminal is suitable for being connected to a neutral line of a power supply line, and the voltage detection module is used to detect the voltage of each phase of the multi-phase power supply line to obtain multiple voltage detection signals; A metering module, wherein the metering module is respectively connected to the voltage detection module and the plurality of current detection units, and is used to sample the plurality of voltage detection signals and the plurality of current detection signals, and obtain a plurality of first voltages according to the plurality of voltage detection signals, and calculate a plurality of first currents according to the plurality of current detection signals, and determine first electric energy metering data of the multi-phase power supply line based on the plurality of first voltages and the plurality of first currents.

2. The low-voltage power distribution switch according to claim 1, characterized in that: The current detection unit comprises: A plurality of current transformers, wherein input ends of the plurality of current transformers are coupled and connected correspondingly to the plurality of current branches, and each of the current transformers is used to detect the current of the corresponding current branch to obtain the branch current detection signal; An adder module, wherein the input end of the adder module is connected to the output ends of the multiple current transformers, the output end of the adder module is connected to the metering module, and the adder module is used to sum the multiple branch current detection signals to obtain the current detection signal of the corresponding phase power supply line.

3. The low-voltage power distribution switch according to claim 2, characterized in that: The adder module comprises: A plurality of signal buffers, wherein input ends of the plurality of signal buffers are correspondingly connected to output ends of the plurality of current transformers, and each of the signal buffers is used to buffer a corresponding branch current detection signal; An adder, wherein the multiple input ends of the adder are correspondingly connected to the output ends of the multiple signal buffers, the output end of the adder is connected to the metering module, and the adder is used to sum the buffered multiple branch current detection signals to obtain the current detection signal of the corresponding phase power supply line.

4. The low-voltage power distribution switch according to claim 3, characterized in that: The signal buffer comprises: a first resistor, one end of which is connected to a first output end of a corresponding current transformer; a second resistor, one end of which is connected to a second output end of the corresponding current transformer; a first operational amplifier, wherein a first input terminal of the first operational amplifier is connected to the other end of the first resistor, a second input terminal of the first operational amplifier is connected to the other end of the second resistor, and an output terminal of the first operational amplifier is connected to a corresponding input terminal of the adder; a third resistor, the third resistor being connected in series between the second input terminal of the first operational amplifier and ground; A fourth resistor is connected in series between the first input terminal and the output terminal of the first operational amplifier.

5. The low-voltage power distribution switch according to claim 4, characterized in that: The first resistor, the second resistor, the third resistor and the fourth resistor have the same resistance value.

6. The low-voltage power distribution switch according to any one of claims 3 to 5, characterized in that: The adder comprises: a plurality of fifth resistors, one end of each of the plurality of fifth resistors being connected to the output ends of each of the plurality of signal buffers; a second operational amplifier, wherein a first input terminal of the second operational amplifier is connected to the other end of the plurality of fifth resistors, a second input terminal of the second operational amplifier is grounded, and an output terminal of the second operational amplifier is connected to the metering module; A sixth resistor is connected in series between the first input terminal and the output terminal of the second operational amplifier.

7. The low-voltage power distribution switch according to claim 6, characterized in that: The fifth resistor and the sixth resistor have the same resistance value.

8. The low-voltage power distribution switch according to claim 1, characterized in that: The current detection module also includes: A shunt, wherein an input end of the shunt serves as an input end of the current detection module; A combiner, wherein the multiple input ends of the combiner are correspondingly connected to the multiple output ends of the diverter through multiple voltage connection lines, and the output end of the combiner serves as the output end of the current detection module; Wherein, a plurality of current branches are formed by the current divider, the current combiner and a plurality of the voltage connection lines, and are connected in parallel between the input end and the output end of the corresponding current detection module.

9. The low-voltage power distribution switch according to claim 8, characterized in that: The shunt includes a first conductive member, a voltage input line and a plurality of first voltage branch lines, wherein one end of the voltage input line serves as an input end of the shunt, the other end of the voltage input line is connected to the input end of the first conductive member, one end of the plurality of first voltage branch lines is connected to a plurality of output ends of the first conductive member, and the other end of the plurality of first voltage branch lines serves as a plurality of output ends of the shunt, wherein the plurality of output ends of the first conductive member are located on the same side of the first conductive member, and the plurality of output ends of the first conductive member and the input end of the first conductive member are located on different sides of the first conductive member.

10. The low-voltage power distribution switch according to claim 8 or 9, characterized in that: The combiner includes a second conductive member, a plurality of second voltage branches and a voltage output line, wherein one end of the plurality of second voltage branches serves as a plurality of input ends of the combiner, the other end of the plurality of second voltage branches is connected to a plurality of input ends of the second conductive member, one end of the voltage output line is connected to an output end of the second conductive member, and the other end of the voltage output line serves as an output end of the combiner, wherein the plurality of input ends of the second conductive member are located on the same side of the second conductive member, and the plurality of input ends of the second conductive member and the output end of the second conductive member are located on different sides of the second conductive member.

11. The low voltage power distribution switch according to claim 2, characterized in that: The multiple current transformers are divided into at least one transformer group, which includes two current transformers symmetrically arranged on both sides of the support plate and with opposite winding directions, and the winding directions of two adjacent current transformers located on the same side of the support plate are opposite.

12. The low voltage power distribution switch according to claim 1, characterized in that: The low-voltage power distribution switch also includes: an ADC sampling module, which is connected to the multiple current detection units and is used to sample the multiple current detection signals to obtain multiple current sampling signals, so as to perform power supply protection based on the multiple current sampling signals.

13. The low voltage power distribution switch according to claim 12, characterized in that: The ADC sampling module is also connected to the voltage detection module, and the ADC sampling module is also used to sample multiple voltage detection signals to obtain multiple voltage sampling signals, so as to perform power supply protection based on multiple current sampling signals and multiple voltage sampling signals.

14. The low-voltage power distribution switch according to claim 13, characterized in that: The low-voltage power distribution switch further includes: a main control module, which is connected to the metering module and the ADC sampling module, wherein: The main control module is used to, when the metering module is not invalid, obtain the first electric energy metering data from the metering module; when the metering module is invalid, obtain a plurality of the current sampling signals and a plurality of the voltage sampling signals from the ADC sampling module, and determine the first electric energy metering data based on the plurality of the current sampling signals and the plurality of the voltage sampling signals; The main control module is further used to, when the ADC sampling module is not failed, obtain a plurality of the current sampling signals and a plurality of the voltage sampling signals from the ADC sampling module, so as to perform power supply protection based on the plurality of the current sampling signals and the plurality of the voltage sampling signals; and when the ADC sampling module fails, obtain a plurality of the first currents and a plurality of the first voltages from the metering module, so as to perform power supply protection based on the plurality of the first currents and the plurality of the first voltages.

15. The low voltage power distribution switch according to claim 14, characterized in that: The main control module is further used to obtain a plurality of the voltage sampling signals from the ADC sampling module, and to obtain a plurality of the first voltages from the metering module, and to determine whether the metering module and the ADC sampling module are failed based on the plurality of the voltage sampling signals and the plurality of the first voltages.

16. The low voltage power distribution switch according to claim 15, characterized in that: The main control module is used to calculate a plurality of second voltages according to the plurality of voltage sampling signals, obtain a voltage difference between each of the first voltages and a corresponding second voltage to obtain a plurality of voltage difference values, and determine whether the metering module and the ADC sampling module are failed based on the plurality of first voltages and the plurality of second voltages when any voltage difference value among the plurality of voltage difference values ​​is greater than or equal to a first preset voltage difference threshold.

17. The low-voltage power distribution switch according to claim 16, characterized in that: The main control module is used to determine whether the metering module and the ADC sampling module are failed based on at least one of the DC components, amplitudes, waveform distortion, power, power factor, frequency and phase sequence corresponding to the first voltages and the second voltages.

18. The low-voltage power distribution switch according to claim 17, characterized in that: The main control module is used to determine that the metering module is invalid when the DC component of the first voltage is greater than a preset DC component; and to determine that the ADC sampling module is invalid when the DC component of the second voltage is greater than the preset DC component.

19. The low-voltage power distribution switch according to claim 17, characterized in that: The main control module is used to determine that the metering module is invalid when the amplitude of the first voltage is not within a preset amplitude range; and to determine that the ADC sampling module is invalid when the amplitude of the second voltage is not within the preset amplitude range.

20. The low voltage power distribution switch according to claim 17, characterized in that: The main control module is used to determine that the metering module is invalid when the waveform distortion of the first voltage is greater than a first preset distortion, or the waveform distortion of the first voltage is greater than the waveform distortion of the second voltage, and the difference between the waveform distortion of the first voltage and the waveform distortion of the second voltage is greater than a second preset distortion; and determine that the ADC sampling module is invalid when the waveform distortion of the second voltage is greater than the first preset distortion, or the waveform distortion of the second voltage is greater than the waveform distortion of the first voltage, and the difference between the waveform distortion of the second voltage and the waveform distortion of the first voltage is greater than the second preset distortion.

21. The low-voltage power distribution switch according to claim 17, characterized in that: The main control module is used to determine that the metering module is invalid when the first power corresponding to the first voltage is negative; and to determine that the ADC sampling module is invalid when the second power corresponding to the second voltage is negative.

22. The low voltage power distribution switch according to claim 17, characterized in that: The main control module is used to determine that the metering module has failed when a first power factor corresponding to the first voltage is less than a preset power factor; and to determine that the ADC sampling module has failed when a second power factor corresponding to the second voltage is less than the preset power factor.

23. The low voltage power distribution switch according to claim 17, characterized in that: The main control module is used to determine that the ADC sampling module has failed when the frequency difference between the frequency of the first voltage and the preset frequency is smaller than the frequency difference between the frequency of the second voltage and the preset frequency, and the frequency difference between the frequency of the second voltage and the frequency of the first voltage is larger than the preset frequency difference; and determine that the metering module has failed when the frequency difference between the frequency of the second voltage and the preset frequency is smaller than the frequency difference between the frequency of the first voltage and the preset frequency, and the frequency difference between the frequency of the first voltage and the frequency of the second voltage is larger than the preset frequency difference.

24. The low voltage power distribution switch according to claim 17, characterized in that: The main control module is used to determine that the metering module is invalid when the phase sequence of the plurality of first voltages is different from the preset phase sequence; and to determine that the ADC sampling module is invalid when the phase sequence of the plurality of second voltages is different from the preset phase sequence.

25. The low voltage power distribution switch according to claim 14, characterized in that: The first frequency at which the main control module obtains the first currents and the first voltages from the metering module is less than the second frequency at which the main control module obtains the current sampling signals and the voltage sampling signals from the ADC sampling module, wherein: The main control module is further configured to perform power supply protection based on a plurality of the first currents, a plurality of the first voltages, and the first frequency when the ADC sampling module fails.

26. The low-voltage power distribution switch according to claim 16, characterized in that: The main control module is also used to correct multiple first voltages and multiple first currents based on the ratio of the second voltage to the first voltage when each of the multiple voltage difference values ​​is less than the first preset voltage difference threshold and greater than a second preset voltage difference threshold, wherein the second preset voltage difference threshold is less than the first preset voltage difference threshold.

27. The low voltage power distribution switch according to claim 14, characterized in that: The main control module is further used to analyze and process the first electric energy metering data to obtain second electric energy metering data.

28. The low voltage power distribution switch according to claim 14, characterized in that: The low voltage power distribution switch also includes: A protection control module, the protection control module is connected to the switch module and is used to control the switch module; The main control module is also connected to the protection control module, and the main control module is also used to generate a protection signal and send it to the protection control module based on multiple current sampling signals and multiple voltage sampling signals, or based on multiple first currents and multiple first voltages, so that the protection control module controls the switch module to disconnect based on the protection signal for power supply protection.

29. The low-voltage power distribution switch according to claim 28, characterized in that: The low-voltage power distribution switch also includes: a state acquisition module, which is connected to the switch module and the main control module, and is used to acquire the switch state and / or power supply protection mode of the switch module and send it to the main control module.

30. The low voltage power distribution switch according to claim 29, characterized in that: The low-voltage distribution switch also includes: a proxy module and an isolation module, the proxy module is connected to the metering module, the ADC sampling module, the protection control module, the state acquisition module and the isolation module, and the isolation module is connected to the main control module, wherein the proxy module is used to obtain the first electric energy metering data, multiple first voltages, multiple first currents, multiple voltage sampling signals, multiple current sampling signals, and the switch state and / or power supply protection mode, and send them to the main control module through the isolation module, and receive the protection signal through the isolation module and send it to the protection control module.

31. The low voltage power distribution switch according to claim 30, characterized in that: The priority of the proxy module sending the data of the metering module is lower than the priority of sending the data of the ADC sampling module and is higher than the priority of sending the data of the status acquisition module.

32. The low voltage power distribution switch according to claim 30, characterized in that: The low-voltage power distribution switch also includes: a first power supply module and a second power supply module, wherein the input end of the first power supply module is connected to multiple input ends of the switch module, the output end of the first power supply module is connected to the input end of the second power supply module, and the output end of the second power supply module is connected to the isolation module, wherein the first power supply module is used to convert the first power supply voltage provided by the multi-phase power supply line into a second power supply voltage, and the second power supply module is used to convert the second power supply voltage into a third power supply voltage and provide it to the isolation module, and the proxy module and the main control module are powered by the isolation module.

33. A power supply device, characterized in that: Comprising a low-voltage power distribution switch according to any one of claims 1-32.

Images