CN112763820A - Undervoltage coil detection device and power distribution cabinet detection system - Google Patents
Undervoltage coil detection device and power distribution cabinet detection system Download PDFInfo
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- G—PHYSICS
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- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R27/00—Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
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Abstract
The application relates to an undervoltage coil detection device and a power distribution cabinet detection system. The device includes: the low-frequency voltage measuring circuit comprises a low-frequency voltage generating module, a protective impedance and a measuring loop, wherein the input end of the low-frequency voltage generating module is connected with a power supply end, the first output end of the low-frequency voltage generating module is connected with one end of the protective impedance, and the other end of the protective impedance is connected with the second output end of the low-frequency voltage generating module through an undervoltage coil and the measuring loop; working voltage is connected between a first connecting terminal of the undervoltage coil and a second connecting terminal of the undervoltage coil; the low-frequency voltage generation module is used for carrying out variable-frequency voltage reduction processing on the working voltage and then inputting the working voltage to the protection impedance; the low-frequency alternating voltage is input to a first connecting terminal of the undervoltage coil through the protection impedance; the metering loop is used for calculating a resistance value between the first wiring terminal and the second wiring terminal according to the voltage on the first wiring terminal and determining whether an undervoltage coil exists in the line to be tested. The device can realize the electrified detection of the undervoltage coil.
Description
Technical Field
The application relates to the technical field of under-voltage coil detection, in particular to an under-voltage coil detection device and a power distribution cabinet detection system.
Background
The undervoltage coil is used for realizing undervoltage protection, can be used in cooperation with devices for controlling the on-off of circuits such as a circuit breaker and the like, and when the voltage in the circuit to be tested is lower than the preset voltage, the magnetic field suction force generated in the undervoltage coil is insufficient, so that the circuit breaker cannot be closed, and the power supply of the downstream is cut off to protect the downstream electrical appliances. However, most of the undervoltage states in the line to be tested are instantaneous, and the undervoltage coil in the line to be tested also cuts off the power supply of the downstream under the instantaneous undervoltage state, and frequent power failure can cause the damage of the downstream electrical appliance, so that the line to be tested needs to be detected whether the undervoltage coil exists or not.
At present, whether the line to be detected has the detection of an undervoltage coil or not needs to be subjected to power failure detection, but the power failure detection process is complicated, and the normal operation of an electric appliance is influenced.
Disclosure of Invention
In view of the above, it is necessary to provide an undervoltage coil detection device and a power distribution cabinet detection system for solving the above technical problems.
A first aspect of an embodiment of the present application provides an undervoltage coil detection device, including: the low-frequency voltage measuring circuit comprises a low-frequency voltage generating module, a protective impedance and a metering loop, wherein the input end of the low-frequency voltage generating module is connected with a power supply end, the first output end of the low-frequency voltage generating module is connected with one end of the protective impedance, the other end of the protective impedance is connected with a first wiring terminal of an undervoltage coil in a circuit to be measured, and a second wiring terminal of the undervoltage coil is connected with the second output end of the low-frequency voltage generating module through the metering loop; working voltage is connected between a first connecting terminal of the undervoltage coil and a second connecting terminal of the undervoltage coil;
the low-frequency voltage generation module is used for carrying out variable-frequency voltage reduction processing on the working voltage to obtain low-frequency alternating-current voltage and then inputting the low-frequency alternating-current voltage to the protection impedance; the low-frequency alternating voltage is input to a first connecting terminal of the undervoltage coil through the protection impedance;
and the metering loop is used for calculating the resistance value between the first wiring terminal and the second wiring terminal according to the voltage on the second wiring terminal and determining whether the undervoltage coil exists in the circuit to be tested according to the resistance value.
In one embodiment, the low-frequency voltage generating module includes an inverting unit and a low-frequency transforming unit; the power supply end is connected with the low-frequency transformation unit through the inversion unit, the first output end of the low-frequency transformation unit is connected with one end of the protective impedance, and the second output end of the low-frequency transformation unit is connected with the metering loop;
the inversion unit is used for inverting the direct-current voltage into alternating-current voltage and supplying power to the low-frequency transformation unit through the inverted alternating-current voltage;
the low-frequency voltage transformation unit is used for transforming the alternating voltage into low-frequency alternating voltage, inputting the low-frequency alternating voltage into the protection impedance, and supplying power to the protection impedance through the low-frequency alternating voltage.
In one embodiment, the power source terminal is an ac power source, and the low-frequency voltage generating module further includes: the voltage regulating and transforming unit and the rectifying unit are connected with the voltage regulating and transforming unit;
the power supply end is connected with the inversion unit through the voltage regulating and transforming unit and the rectification unit;
the voltage regulating and transforming unit is used for regulating the alternating voltage connected into the voltage regulating and transforming unit to obtain regulated alternating voltage and supplying power to the rectifying unit through the regulated alternating voltage; the regulated alternating voltage is less than the alternating voltage connected to the voltage regulating and transforming unit;
the rectifying unit is used for rectifying the adjusted alternating voltage to obtain direct voltage and supplying direct current to the inverting unit.
In one embodiment, the low-frequency voltage generating module further includes a filtering unit; the rectification unit is connected with the inversion unit through the filtering unit;
the filtering unit is used for filtering the direct-current voltage output by the rectifying unit to obtain the filtered direct-current voltage and supplying direct-current power to the inverting unit.
In one embodiment, the line to be tested is a line to be tested on a power distribution cabinet, the power distribution cabinet comprises a plurality of switches, and each switch is correspondingly connected with two wiring terminals of the undervoltage coil;
the input end of the voltage regulating and transforming unit is connected with the voltage output end of the power distribution cabinet.
In one embodiment, one switch of the power distribution cabinet corresponds to one undervoltage coil detection device.
In one embodiment, the protection impedance includes a first resistor and an inductor, the first resistor is electrically connected to the inductor, and the first output terminal of the low-frequency voltage generation module is connected to the first connection terminal of the under-voltage coil through the first resistor and the inductor.
In one embodiment, the metering loop includes a second resistor, a rectifier bridge and an ammeter; the rectifier bridge is connected in parallel with the second resistor after being connected in series with the ammeter, and a second wiring terminal of the undervoltage coil is connected with a second output end of the low-frequency voltage generation module through the second resistor.
In one embodiment, the frequency of the low-frequency ac voltage is any value between 0.1 HZ and 0.4 HZ.
A second aspect of the embodiment of the present application provides a power distribution cabinet detection system, which includes a power distribution cabinet and an under-voltage coil detection device provided in the embodiment of the present application, wherein a plurality of switches and two connection terminals of an under-voltage coil correspondingly connected to each switch are arranged on the power distribution cabinet, and each switch corresponds to one under-voltage coil detection device;
the undervoltage coil detection device is respectively connected with the voltage output end of the power distribution cabinet and two wiring terminals of the undervoltage coil.
Above-mentioned under-voltage coil detection device and switch board detecting system, this detection device includes: the low-frequency voltage measuring circuit comprises a low-frequency voltage generating module, a protective impedance and a metering loop, wherein the input end of the low-frequency voltage generating module is connected with a power supply end, the first output end of the low-frequency voltage generating module is connected with one end of the protective impedance, the other end of the protective impedance is connected with a first wiring terminal of an undervoltage coil in a circuit to be measured, and a second wiring terminal of the undervoltage coil is connected with the second output end of the low-frequency voltage generating module through the metering loop; and working voltage is connected between the first wiring terminal of the undervoltage coil and the second wiring terminal of the undervoltage coil. In the embodiment of the application, based on the connection relationship between the low-frequency voltage generation module and the protection impedance, the low-frequency voltage generation module can perform variable-frequency voltage reduction processing on the working voltage and input the obtained low-frequency alternating voltage to the first wiring terminal of the undervoltage coil through the protection impedance; because the protection impedance has higher impedance characteristic to the high-frequency working voltage, but presents the characteristic of low impedance and high conduction to the low-frequency alternating voltage, thereby the protection impedance can carry out isolation protection to the original working voltage on the undervoltage coil, and simultaneously can insert the low-frequency alternating voltage into the undervoltage coil, and then the metering loop can calculate the resistance value between the first connecting terminal and the second connecting terminal according to the voltage on the first connecting terminal under the condition that the undervoltage coil normally works to determine whether the undervoltage coil exists in the line to be measured. The method of the embodiment can not only realize the live-line detection of the undervoltage coil on the line to be detected, but also avoid the conflict with the high-frequency working voltage of the undervoltage coil, and the low-frequency voltage generation module outputs the low-frequency alternating voltage which can not generate magnetic bias on the undervoltage coil, can also prevent the current from flowing backwards, can not cause extra load for the original circuit, and ensures the normal operation of the line to be detected.
Drawings
FIG. 1 is a schematic structural diagram of an undervoltage coil detection device according to an embodiment;
FIG. 2 is a schematic structural diagram of an undervoltage coil detection device in another embodiment;
FIG. 3 is a schematic structural diagram of an undervoltage coil detection device in another embodiment;
FIG. 4 is a schematic diagram of a protective impedance;
FIG. 5 is a schematic diagram of a metering circuit;
FIG. 6 is a schematic structural diagram of an undervoltage coil detection device according to another embodiment;
fig. 7 is a schematic structural diagram of a power distribution cabinet detection system in one embodiment.
Description of reference numerals:
11. a low frequency voltage generation module; 101. An inversion unit; 102. A low-frequency voltage transformation unit;
103. a voltage regulating and transforming unit; 104. A rectifying unit; 105. A filtering unit;
12. a protection impedance; 121. A first resistor; 122. An inductance;
131. a first connection terminal; 132. A second connection terminal;
14. a metering circuit; 141. A second resistor; 142. A rectifier bridge;
143. an ammeter; 15. A power distribution cabinet; 16. And (4) switching.
Detailed Description
In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.
The undervoltage coil is used for realizing undervoltage protection, can be used in cooperation with devices for controlling the on-off of circuits such as a circuit breaker and the like, and when the voltage in the circuit to be tested is lower than the preset voltage, the magnetic field suction force generated in the undervoltage coil is insufficient, so that the circuit breaker cannot be closed, and the power supply of the downstream is cut off to protect the downstream electrical appliances. However, most of the undervoltage states in the line to be tested are instantaneous, and the undervoltage coil in the line to be tested also cuts off the power supply of the downstream under the instantaneous undervoltage state, and frequent power failure can cause the damage of the downstream electrical appliance, so that the line to be tested needs to be detected whether the undervoltage coil exists or not.
At present, whether the line to be detected has the detection of an undervoltage coil or not needs to be subjected to power failure detection, but the power failure detection process is complicated, and the normal operation of an electric appliance is influenced. A need has arisen for a means of undervoltage coil detection without a power outage.
Fig. 1 is a schematic structural diagram of an undervoltage coil detection device provided in an embodiment of the present application, and as shown in fig. 1, the undervoltage coil detection device includes a low-frequency voltage generation module 11, a protection impedance 12, and a measurement loop 14, an input end of the low-frequency voltage generation module 11 is connected to a power supply end, a first output end of the low-frequency voltage generation module 11 is connected to one end of the protection impedance 12, another end of the protection impedance 12 is connected to a first connection terminal 131 of an undervoltage coil in a line to be detected, and a second connection terminal 132 of the undervoltage coil is connected to a second output end of the low-frequency voltage generation module 11 through the measurement loop 14; the operating voltage is connected between the first connection terminal 131 of the undervoltage coil and the second connection terminal 132 of the undervoltage coil.
The low-frequency voltage generation module 11 is configured to perform variable-frequency voltage reduction processing on a working voltage to obtain a low-frequency alternating-current voltage, and then input the low-frequency alternating-current voltage to the protection impedance 12; the low-frequency alternating voltage is input to a first connection terminal 131 of the undervoltage coil through a protection impedance 12; and the metering loop 14 is used for calculating a resistance value between the first connection terminal 131 and the second connection terminal 132 according to the voltage on the second connection terminal 131, and determining whether an undervoltage coil exists in the line to be tested according to the resistance value.
Specifically, the input end of the low-frequency voltage generating module 11 in the embodiment of the present application is connected to a power supply end, the power supply output by the power supply end may be an ac power supply or a dc power supply, the low-frequency voltage generating module 11 is configured to convert a dc voltage or an ac voltage output by the power supply end into a low-frequency ac voltage, and a form of the low-frequency voltage generating module 11 is not specifically limited herein. Optionally, the frequency of the low-frequency ac voltage generated by the low-frequency voltage generation module 11 is any value between 0.1 HZ and 0.4 HZ. The frequency of the low-frequency alternating voltage is one hundredth of the working frequency of the undervoltage coil, the difference between the frequency of the low-frequency alternating voltage and the working frequency of the undervoltage coil is hundreds of times, and the low-frequency alternating voltage is a sine wave, so that the low-frequency alternating voltage can be prevented from colliding with the high-frequency working voltage of the undervoltage coil and can not generate magnetic biasing on the undervoltage coil.
The protection impedance 12 in the undervoltage coil detection device has a higher impedance characteristic to the high-frequency working voltage, but presents a characteristic of low impedance and high conduction to the low-frequency alternating-current voltage, so that the protection impedance 12 can isolate and protect the original working voltage on the undervoltage coil, and simultaneously can connect the low-frequency alternating-current voltage generated by the low-frequency voltage generation module 11 into the first wiring terminal 131 of the undervoltage coil.
Optionally, fig. 4 is a schematic structural diagram of the protection impedance provided in the embodiment of the present application, and as shown in fig. 4, the protection impedance 12 includes a first resistor 121 and an inductor 122, the first resistor 121 is electrically connected to the inductor 122, and a first output terminal of the low-frequency voltage generating module 11 is connected to a first connection terminal 131 of the undervoltage coil through the first resistor 121 and the inductor 122. The first resistor 121 may also include one resistor and one sliding rheostat, or may also include two resistors, three resistors, four resistors, and the like, where the resistors may be connected in parallel, may be connected in series, may also be connected in series after being connected in parallel, or may be connected in parallel after being connected in series, where the first resistor 121 is not specifically limited; the inductor 122 is a physical quantity for measuring the electromagnetic induction capability of the coil, and is mainly divided into a magnetic core inductor 122 and an air core inductor 122, the inductor 122 has a characteristic of preventing alternating current from passing through and allowing direct current to pass through smoothly, and the higher the frequency of the alternating current is, the larger the impedance of the coil on the inductor 122 is, that is, the larger the impedance of the high-frequency alternating current passing through the inductor 122 is, because of the characteristic of the inductor 122 in the protection impedance 12, the protection impedance 12 can perform isolation protection on the original working voltage on the under-voltage coil, and simultaneously, the low-frequency alternating voltage generated by the low-frequency voltage generation module 11 can be connected to the first connection terminal 131 of the under-voltage coil. The inductors 122 provided in this embodiment may be magnetic core or iron core inductors, magnetic core adjustable inductors, sliding adjustable inductors, series mutual inductance adjustable inductors, and the like, the number of the inductors 122 is at least one, and may also be multiple, the multiple inductors 122 may be connected in series, or in parallel after being connected in parallel, and the coils on the inductors 122 may be single-layer coils, honeycomb-type coils, iron powder core coils, copper core coils, and the like. The representation of the inductor 122 is not particularly limited.
Optionally, the protection impedance 12 may include only an inductor; or, the inductance and the capacitance are connected in series; or the inductor and the capacitor are connected in parallel; the inductance and capacitance resistors are connected in series; the lc resistors are connected in parallel to form various combinations, so long as the protection impedance 12 can isolate the working voltage and input the low-frequency ac voltage to the first connection terminal 131 of the under-voltage coil, and the specific form of the protection impedance 12 is not limited herein.
In addition, the measurement circuit 14 may detect a performance parameter of the under-voltage coil, and calculate a resistance value between the first connection terminal 131 and the second connection terminal 132 of the under-voltage coil according to the detected characteristic parameter, so as to determine whether the under-voltage coil exists in the line to be measured according to a calculation result. Optionally, fig. 5 is a schematic structural diagram of a metering loop according to another embodiment of the present disclosure, and as shown in fig. 5, the metering loop 14 includes a second resistor 141, a rectifier bridge 142, and an ammeter 143; the rectifier bridge 142 is connected in series with the ammeter 143 and then connected in parallel to the second resistor 141, and the second connection terminal 132 of the undervoltage coil is connected to the second output terminal of the low-frequency voltage generating module 11 through the second resistor 141. The metering loop 14 is provided with an ammeter 143, which can measure the current between two terminals of the undervoltage coil through the ammeter 143, and because the low-frequency voltage generating module 11 generates the low-frequency alternating voltage with the preset voltage value, the resistance values of the two terminals of the undervoltage coil can be calculated according to ohm's law, and if the resistance value is infinite, it can be judged that there is no undervoltage coil between the two connection terminals; if the resistance value is estimated, an undervoltage coil is judged to be arranged between the two connecting terminals.
Optionally, the metering circuit 14 may also include only an ammeter 143 or a multimeter, as long as the parameters that can determine whether there is an undervoltage coil can be detected, and the specific form of the metering circuit 14 is not specifically limited herein.
In addition, in this embodiment, the first connection terminal 131 of the under-voltage coil and the second connection terminal 132 of the under-voltage coil are reserved in the circuit to be tested, and a working voltage is connected between the first connection terminal 131 of the under-voltage coil and the second connection terminal 132 of the under-voltage coil, where the working voltage may be a working voltage provided by a power supply terminal, and when the working voltage is connected between two connection terminals of the under-voltage coil, it indicates that the under-voltage coil is in a working state at this time. Optionally, the line to be tested in this embodiment may be a line on a power distribution cabinet, or may also be a line in other power distribution networks, and this embodiment does not limit the specific form of the line to be tested, as long as the line realizes protection of an electrical appliance through an undervoltage coil.
The embodiment of the application provides an under-voltage coil detection device, this detection device includes: the low-frequency voltage measuring circuit comprises a low-frequency voltage generating module, a protective impedance and a metering loop, wherein the input end of the low-frequency voltage generating module is connected with a power supply end, the first output end of the low-frequency voltage generating module is connected with one end of the protective impedance, the other end of the protective impedance is connected with a first wiring terminal of an undervoltage coil in a circuit to be measured, and a second wiring terminal of the undervoltage coil is connected with the second output end of the low-frequency voltage generating module through the metering loop; and working voltage is connected between the first wiring terminal of the undervoltage coil and the second wiring terminal of the undervoltage coil. In the embodiment of the application, based on the connection relationship between the low-frequency voltage generation module and the protection impedance, the low-frequency voltage generation module can perform variable-frequency voltage reduction processing on the working voltage and input the obtained low-frequency alternating voltage to the first wiring terminal of the undervoltage coil through the protection impedance; because the protection impedance has higher impedance characteristic to the high-frequency working voltage, but presents the characteristic of low impedance and high conduction to the low-frequency alternating voltage, thereby the protection impedance can carry out isolation protection to the original working voltage on the undervoltage coil, and simultaneously can insert the low-frequency alternating voltage into the undervoltage coil, and then the metering loop can calculate the resistance value between the first connecting terminal and the second connecting terminal according to the voltage on the first connecting terminal under the condition that the undervoltage coil normally works to determine whether the undervoltage coil exists in the line to be measured. The method of the embodiment can not only realize the live-line detection of the undervoltage coil on the line to be detected, but also avoid the conflict with the high-frequency working voltage of the undervoltage coil, and the low-frequency alternating voltage output by the low-frequency voltage generating module is alternating voltage which cannot bias the undervoltage coil, and can also prevent the current from flowing backwards, which cannot cause extra load for the original loop, thereby ensuring the normal operation of the line to be detected.
Fig. 2 is a schematic structural diagram of an under-voltage coil detection device according to another embodiment of the present application, and as shown in fig. 2, when the power supply terminal is a dc power supply, that is, the power supply terminal provides a dc voltage for the under-voltage coil detection device, the low-frequency voltage generation module 11 includes an inverter unit 101 and a low-frequency transformer unit 102. The power supply end is connected with the low-frequency transformation unit 102 through the inversion unit 101, a first output end of the low-frequency transformation unit 102 is connected with one end of the protective impedance 12, and a second output end of the low-frequency transformation unit 102 is connected with the metering loop 14; the inversion unit 101 is configured to invert the dc voltage into an ac voltage, and supply power to the low-frequency transformation unit 102 through the inverted ac voltage; the low-frequency transforming unit 102 is configured to transform the ac voltage into a low-frequency ac voltage, input the low-frequency ac voltage to the protection impedance 12, and supply power to the protection impedance 12 through the low-frequency ac voltage.
Specifically, the dc power may be a dc power provided by a power supply terminal, and based on the above description of the protection impedance 12, the inductor 122 has a characteristic of blocking ac power and allowing dc power to pass through, so that the dc voltage may affect the normal operation of the under-voltage coil. An object of the under-voltage coil detection device that this application embodiment provided is exactly that do not influence under-voltage coil's normal work when detecting, realize electrified detection to under-voltage coil, so in order not to influence under-voltage coil's normal work, need insert inverter unit 101 with above-mentioned DC power supply, through inverter unit 101 contravariant, become alternating voltage with the direct voltage of this DC power supply output contrary, alternating voltage is the sine wave, flow into under-voltage coil after, can not make under-voltage coil produce asymmetric excitation and influence under-voltage coil's normal work. However, since the inverter unit 101 itself can only output the ac voltage with a fixed voltage value, which may not meet the detection requirement, the ac voltage flowing out from the inverter unit 101 needs to be transformed, the process of transforming the ac voltage is performed by the low frequency transforming unit 102, and the low frequency transforming unit 102 adjusts the voltage value of the inverted ac voltage to the low frequency ac voltage with the preset voltage value and outputs the low frequency ac voltage. If the voltage value of the ac voltage output from inverter unit 101 can satisfy the detection requirement, low-frequency transformer unit 102 does not need to adjust the ac voltage inverted from inverter unit 101. The low frequency transforming unit 102 does not have a function of adjusting a voltage value, but also has a function of isolating the protection impedance 12 and the metering loop 14, so as to prevent the current from flowing backwards to cause an additional load to the original loop. Optionally, the inverting unit 101 may be an inverter, and the low-frequency transforming unit 102 is a low-frequency transformer; optionally, the inverter may be composed of an inverter bridge, control logic, and a filter circuit. Alternatively, the low frequency transformer may be an R-type transformer.
The undervoltage coil detection device that this application embodiment provided, under the power is DC power supply's the condition, through inverter unit and low frequency unit generation low frequency alternating voltage, this low frequency alternating voltage's frequency is several hundredths of undervoltage coil operating voltage frequency, can not produce the interference to undervoltage coil's operating voltage, simultaneously, because the low frequency alternating voltage who produces is the sine wave, so can not make undervoltage coil produce asymmetric excitation and influence its normal work. Meanwhile, the low-frequency voltage transformation unit can adjust the voltage value of the inverted alternating voltage to the low-frequency alternating voltage required by detection, and can also isolate and protect impedance and measure a loop to prevent the current from flowing backwards to cause extra load on the original loop. And a reliable condition is provided for realizing the live detection of the undervoltage coil.
Fig. 3 is a schematic structural diagram of an undervoltage coil detection device according to another embodiment of the present application, and as shown in fig. 3, when a power supply end in this embodiment may be an ac power supply, that is, when the power supply end provides an ac voltage for the undervoltage coil detection device, the low-frequency voltage generation module 11 may further include, in addition to the inverter unit 101 and the low-frequency transformer unit 102: a voltage regulating and transforming unit 103 and a rectifying unit 104 connected to the voltage regulating and transforming unit 103; the power supply end is connected with the inverter unit 101 through the voltage regulating and transforming unit 103 and the rectifying unit 104; the voltage regulating and transforming unit 103 is used for regulating the alternating voltage connected to the voltage regulating and transforming unit 103 to obtain a regulated alternating voltage, and supplying power to the rectifying unit 104 through the regulated alternating voltage; the regulated alternating voltage is less than the alternating voltage connected to the voltage regulating and transforming unit 103; the rectifying unit 104 is configured to rectify the adjusted ac voltage to obtain a dc voltage, and to supply dc power to the inverting unit 101.
Specifically, the ac power supply may be an ac power supply outputted from a power supply terminal, and since the voltage value and the frequency of the ac voltage outputted from the ac power supply are generally high, it is necessary to perform a step-down process on the ac voltage by the voltage regulating and transforming unit 103, that is, to reduce the voltage value of the ac voltage and then reduce the frequency of the ac voltage, and since the frequency of the ac voltage cannot be directly reduced, it is necessary to convert the ac voltage into a dc voltage by first rectifying the ac voltage by the rectifying unit 104, and then perform a frequency conversion process on the dc voltage, thereby obtaining a low-frequency dc voltage. Finally, a low-frequency alternating voltage is obtained through the combined action of the inverter unit 101 and the low-frequency transformer unit 102, so as to detect the undervoltage coil.
Optionally, with continued reference to fig. 3, the low-frequency voltage generating module 11 may further include a filtering unit 105; the rectifying unit 104 is connected with the inverting unit 101 through the filtering unit 105; the filtering unit 105 can filter the low-frequency dc voltage output by the rectifying unit 104 to obtain a filtered dc voltage, so as to ensure the quality of the dc voltage input to the inverting unit 101, and can supply dc power to the inverting unit 101. Optionally, the voltage regulating and transforming unit 103 is a voltage regulating transformer, the rectifying unit 104 is a rectifier, and the filtering unit 105 is a filter.
The undervoltage coil detection device that this application embodiment provided can be under the alternating voltage's that the power end provided the condition, handle alternating voltage into direct current voltage through pressure regulating vary voltage unit and rectifier unit, and filter low frequency direct current voltage through the filter unit, guaranteed the quality of input contravariant unit direct current voltage, above-mentioned contravariant unit and low frequency vary voltage unit of reunion, generate corresponding low frequency alternating voltage, can satisfy and carry out the electrified demand that detects to undervoltage coil under different voltages.
Fig. 6 is a schematic structural diagram of another undervoltage coil detection device according to an embodiment of the present application, where the undervoltage coil detection device is applied to a power distribution cabinet, as shown in fig. 6, the line to be detected is a line to be detected on a power distribution cabinet 15, the power distribution cabinet 15 includes a plurality of switches 16, and each switch 16 is correspondingly connected to two connection terminals of an undervoltage coil; the input end of the voltage regulating and transforming unit 103 is connected to the voltage output end of the power distribution cabinet 15.
Particularly, the power distribution cabinet 15 is a final-stage device of a power distribution system, and the power distribution cabinet 15, the lighting power distribution cabinet 15 and the metering cabinet are separated from each other. Including a plurality of switches 16 on the switch board 15, every switch 16 corresponds two binding post of connecting undervoltage coil, and two binding post of undervoltage coil reserve the terminal for switch board 15, that is to say, even binding post's inside does not have undervoltage coil, still can reserve binding post in the position of installation undervoltage coil on switch board 15. The switch board 15 distributes the power of a certain circuit of the previous stage of distribution equipment to the nearby load, which may be a household appliance, for example, through the switch 16 and the undervoltage coil.
Because the most under-voltage state of switch board 15 output voltage is instantaneous, if be provided with under-voltage coil in switch board 15, under-voltage coil is under the state of instantaneous undervoltage, can cut off the power supply of low reaches, frequent outage can cause the damage of next grade electrical apparatus, so just produced the demand of dismantling under-voltage coil in switch board 15, but under-voltage coil in switch board 15 is in a state by the parcel, it goes to confirm whether there is under-voltage coil in the binding post to reserve with the naked eye to have a method, so whether need exist under-voltage coil in the circuit that awaits measuring to switch board 15 and detect.
The undervoltage coil in the line to be tested of the power distribution cabinet 15 may be detected by the undervoltage coil detection device, and optionally, the input end of the undervoltage coil detection device may be connected to the voltage output end of the power distribution cabinet 15. The input end of the undervoltage coil detection device is different along with the different types of the power supply ends. When the power source end is a dc power source, the input end of the undervoltage coil detection device may be the inverter unit 101, and when the power source end is an ac power source, the input end of the undervoltage coil detection device may be the voltage regulating transformer unit 103.
The voltage output end of the power distribution cabinet 15 provides a power supply for the undervoltage coil detection device, and simultaneously provides a working voltage for each switch 16, so that the power distribution cabinet 15 transmits the working voltage to the next stage through the switches 16 and the undervoltage coil to supply power to the next stage of electrical appliances and the like, and the next stage of electrical appliances and the like can work normally; meanwhile, the low-frequency voltage generation module 11 of the undervoltage coil detection device performs frequency conversion and voltage reduction processing on the working voltage to obtain a low-frequency alternating voltage, and inputs the low-frequency alternating voltage to the first connection terminal 131 of the undervoltage coil through the protection impedance 12, so that finally, the metering loop 14 can calculate a resistance value between the first connection terminal 131 and the second connection terminal 132 according to the voltage on the first connection terminal 131, and determine whether the undervoltage coil exists in the line to be detected according to the resistance value. Optionally, a switch 16 of the power distribution cabinet 15 corresponds to an undervoltage coil detection device, that is, a plurality of undervoltage coil detection devices can be arranged on the power distribution cabinet 15, and how many undervoltage coils reserve terminals, and how many undervoltage coil detection devices can be arranged, so that all undervoltage coils on the power distribution cabinet 15 can be detected at one time, and the detection is targeted, and the detection result is more accurate.
The undervoltage coil detection device that this application embodiment provided, based on the above-mentioned description to the device, can be under the switch board can normally work the condition, detect the undervoltage coil in the circuit that awaits measuring of switch board, and can not influence undervoltage coil's normal work, under the condition that detects out to have undervoltage coil in the circuit that awaits measuring, can be when can cutting off the power supply and carry out disposable demolising to the undervoltage coil that needs demolish, avoid many times outage, cause the damage for next stage electrical apparatus.
Fig. 7 is a schematic structural diagram of a power distribution cabinet detection system according to an embodiment of the present application, where the system includes a power distribution cabinet 15 and the undervoltage coil detection device, the power distribution cabinet 15 is provided with a plurality of switches 16, and two connection terminals of an undervoltage coil correspondingly connected to each switch 16, and each switch 16 corresponds to one undervoltage coil detection device; the undervoltage coil detection device is connected with the voltage output end of the power distribution cabinet 15 and two wiring terminals of the undervoltage coil respectively.
Specifically, 15 detecting system of switch board can detect the under-voltage coil in switch board 15 through above-mentioned under-voltage coil detection device, refer to above-mentioned description to the reason that under-voltage coil detected in switch board 15, do not describe herein repeatedly. The voltage output end of the power distribution cabinet 15 provides voltage for the undervoltage coil detection device, the voltage can be alternating current voltage or direct current voltage, the direct current voltage or the alternating current voltage is processed by the low-frequency voltage generation module 11 in the undervoltage coil detection device to generate a low-frequency alternating current voltage, the frequency of the low-frequency alternating current voltage is different from the working voltage of the undervoltage coil by several hundred times, and the low-frequency alternating current voltage does not affect the normal work of the undervoltage coil, meanwhile, the low-frequency alternating current voltage is input to the first connection terminal 131 of the undervoltage coil through the protection impedance 12 in the undervoltage coil detection device, the protection impedance 12 has the characteristic of isolating the high-frequency alternating current voltage and conducting the low-frequency alternating current voltage, and the low-frequency alternating current voltage is sine wave, and does not produce asymmetrical excitation to the undervoltage coil, and avoids affecting the normal work of the undervoltage coil, thereby realizing that under the, and detecting the electrification of the undervoltage coil.
The power distribution cabinet detection system that this application embodiment provided corresponds for every switch and is provided with corresponding under-voltage coil detection device, under the normal condition of working of power distribution cabinet, realization that can be accurate detects under-voltage coil's electrified problem of having a power failure to detect the normal operating that influences electrical apparatus has been solved.
The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.
Claims (10)
1. An undervoltage coil detection device, comprising: the low-frequency voltage measuring circuit comprises a low-frequency voltage generating module, a protective impedance and a metering loop, wherein the input end of the low-frequency voltage generating module is connected with a power supply end, the first output end of the low-frequency voltage generating module is connected with one end of the protective impedance, the other end of the protective impedance is connected with a first wiring terminal of an undervoltage coil in a circuit to be measured, and a second wiring terminal of the undervoltage coil is connected with the second output end of the low-frequency voltage generating module through the metering loop; working voltage is connected between a first connecting terminal of the undervoltage coil and a second connecting terminal of the undervoltage coil;
the low-frequency voltage generation module is used for carrying out frequency conversion voltage reduction processing on the working voltage to obtain a low-frequency alternating voltage and then inputting the low-frequency alternating voltage to the protection impedance; the low-frequency alternating voltage is input to a first wiring terminal of the undervoltage coil through the protection impedance;
and the metering loop is used for calculating a resistance value between the first wiring terminal and the second wiring terminal according to the voltage on the second wiring terminal and determining whether the undervoltage coil exists in the line to be tested according to the resistance value.
2. The detection device according to claim 1, wherein the low-frequency voltage generation module comprises an inversion unit and a low-frequency transformation unit; the power supply end is connected with the low-frequency transformation unit through the inversion unit, a first output end of the low-frequency transformation unit is connected with one end of the protective impedance, and a second output end of the low-frequency transformation unit is connected with the metering loop;
the inversion unit is used for inverting the direct-current voltage into alternating-current voltage and supplying power to the low-frequency transformation unit through the inverted alternating-current voltage;
the low-frequency voltage transformation unit is used for transforming the alternating voltage into the low-frequency alternating voltage, inputting the low-frequency alternating voltage into the protection impedance, and supplying power to the protection impedance through the low-frequency alternating voltage.
3. The detecting device according to claim 2, wherein the power source terminal is an ac power source, and the low-frequency voltage generating module further comprises: the voltage regulating and transforming unit and the rectifying unit are connected with the voltage regulating and transforming unit;
the power supply end is connected with the inversion unit through the voltage regulating and transforming unit and the rectification unit;
the voltage regulating and transforming unit is used for regulating the alternating voltage connected into the voltage regulating and transforming unit to obtain regulated alternating voltage and supplying power to the rectifying unit through the regulated alternating voltage; the regulated alternating voltage is less than the alternating voltage connected to the voltage regulating and transforming unit;
the rectification unit is used for rectifying the adjusted alternating voltage to obtain the direct voltage and supplying direct current to the inversion unit.
4. The detection apparatus according to claim 3, wherein the low frequency voltage generation module further comprises a filtering unit; the rectifying unit is connected with the inverting unit through the filtering unit;
the filtering unit is used for filtering the direct-current voltage output by the rectifying unit to obtain the filtered direct-current voltage, and the direct-current voltage is used for supplying direct-current power to the inverting unit.
5. The detection device according to claim 4, wherein the line to be detected is a line to be detected on a power distribution cabinet, the power distribution cabinet comprises a plurality of switches, and each switch is correspondingly connected with two connection terminals of the undervoltage coil;
and the input end of the voltage regulating and transforming unit is connected with the voltage output end of the power distribution cabinet.
6. The detection device according to claim 5, wherein a switch of the power distribution cabinet corresponds to an undervoltage coil detection device.
7. The detection device as claimed in claim 6, wherein the protection impedance includes a first resistor and an inductor, the first resistor is electrically connected to the inductor, and the first output terminal of the low-frequency voltage generation module is connected to the first connection terminal of the undervoltage coil through the first resistor and the inductor.
8. The sensing device of claim 7, wherein the metering loop comprises a second resistor, a rectifier bridge, and an ammeter; the rectifier bridge is connected in parallel with the ammeter after being connected in series on the second resistor, and a second wiring terminal of the undervoltage coil is connected with a second output end of the low-frequency voltage generation module through the second resistor.
9. The detection device according to any one of claims 2 to 8, wherein the frequency of the low frequency alternating voltage is any value between 0.1 and 0.4 HZ.
10. A switch board detecting system, its characterized in that includes: the power distribution cabinet and the undervoltage coil detection device as claimed in any one of claims 1 to 9, wherein a plurality of switches and two connection terminals of the undervoltage coil correspondingly connected with each switch are arranged on the power distribution cabinet, and each switch corresponds to one undervoltage coil detection device;
the undervoltage coil detection device is respectively connected with the voltage output end of the power distribution cabinet and two wiring terminals of the undervoltage coil.
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| CN202011527518.2A CN112763820B (en) | 2020-12-22 | 2020-12-22 | Undervoltage coil detection device and power distribution cabinet detection system |
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| JP2005269797A (en) * | 2004-03-19 | 2005-09-29 | Matsushita Electric Ind Co Ltd | Dc power supply device |
| CN103944139A (en) * | 2014-04-02 | 2014-07-23 | 江苏永明电气有限公司 | No-voltage delayer of undervoltage coil of circuit breaker |
| CN204696702U (en) * | 2015-06-30 | 2015-10-07 | 山东盛唐新能源电力有限公司 | Grid-connected distribution box |
| CN106443317A (en) * | 2016-10-17 | 2017-02-22 | 国网浙江省电力公司嘉兴供电公司 | Transformer copper-clad aluminum winding detector and detection method |
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2020
- 2020-12-22 CN CN202011527518.2A patent/CN112763820B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005269797A (en) * | 2004-03-19 | 2005-09-29 | Matsushita Electric Ind Co Ltd | Dc power supply device |
| CN103944139A (en) * | 2014-04-02 | 2014-07-23 | 江苏永明电气有限公司 | No-voltage delayer of undervoltage coil of circuit breaker |
| CN204696702U (en) * | 2015-06-30 | 2015-10-07 | 山东盛唐新能源电力有限公司 | Grid-connected distribution box |
| CN106443317A (en) * | 2016-10-17 | 2017-02-22 | 国网浙江省电力公司嘉兴供电公司 | Transformer copper-clad aluminum winding detector and detection method |
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| CN112763820B (en) | 2023-01-03 |
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