An intelligent low-voltage controller, a low-voltage switch control system and a device

Abstract

The present invention relates to an intelligent low-voltage controller, a low-voltage switch control system and a device. An intelligent low-voltage controller includes a processor, a current sampling module, a communication module and a power supply module; the current sampling module, the communication module and the power supply module are respectively connected to the processor; the current sampling module includes a current sampling device and a sampling conversion device; compared with the prior art, it has the following effects: 1. The secondary part of the switch adopts a modular design, supports hot plugging, and is convenient for maintenance; 2. A CT bootstrap switching circuit with an automatic switching function is adopted, and the load resistance of the sampling circuit remains constant when the line current is within the normal load range, effectively improving the sampling accuracy; 3. An auxiliary power supply is integrated inside the switch, and a super capacitor is used as a backup power supply. After the switch is powered off, a power-off event is reported and fault information is uploaded.

Description

Technical Field

[0001] The present invention relates to the field of electrical appliances, and particularly to an intelligent low-voltage controller, a low-voltage switch control system and a device. Background Art

[0002] Intelligent low-voltage switches are key devices applied to low-voltage distribution networks, playing the roles of low-voltage distribution network protection and energy distribution. In existing low-voltage switch devices, due to problems such as low current and voltage measurement accuracy, the power supply module not supporting power outage event reporting, no modular remote communication module, and inconvenient replacement and upgrade of the switch control part circuit, they cannot meet the in-depth application requirements of the ubiquitous power Internet of Things, such as advanced functions like fault judgment, power-on and power-off event reporting, power metering, and topology analysis.

[0003] The patent document with the patent number ZL201610106157.1 discloses a household intelligent leakage protector, which includes a leakage protector body. An operating lever is installed on the upper part of the surface of the leakage protector body. The operating lever is fixedly connected to an electric telescopic rod arranged inside the leakage protector body. A display and an operation panel are also installed on the front surface of the leakage protector body. A storage battery is installed at the bottom inside the leakage protector body. A temperature sensor and a humidity sensor are also installed inside the leakage protector body. The display, the operation panel, the electric telescopic rod, the storage battery, the voltage transformation unit, the thermal relay, the fuse, the temperature sensor, and the humidity sensor are all electrically connected to an intelligent control device installed inside the leakage protector body. This household intelligent leakage protector can export fault information, facilitating users to view and analyze, improving the maintenance efficiency of household circuits, meeting the working requirements of increasingly intelligent household devices, and reducing potential electrical hazards.

[0004] However, the existing technology still has the following disadvantages: 1. CT power supply and measurement use the same current transformer, with low measurement accuracy and difficulty in realizing the metering function; 2. There is no integrated auxiliary power supply inside the switch, and no backup power supply is designed. After the switch power outage, power outage event reporting cannot be carried out, nor can fault information be uploaded to the master station; 3. There is no line topology auxiliary analysis function, affecting line fault judgment; 4. The secondary control part of the switch cannot be replaced, making the switch application inflexible.

[0005] Therefore, there are deficiencies in existing low-voltage control devices, and there is still room for improvement. Summary of the Invention

[0006] In view of the above deficiencies of the existing technology, the purpose of the present invention is to provide an intelligent low-voltage controller, a low-voltage switch control system and a device, which can meet the requirements of the Internet of Things, and can provide one-minute communication power after the power outage in the substation area, be able to report faults or power outage information, and improve the efficiency of fault repair in the substation area.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] An intelligent low-voltage controller includes a processor, a current sampling module, a communication module, and a power supply module; the current sampling module, the communication module, and the power supply module are respectively connected to the processor;

[0009] The current sampling module includes a current sampling device and a sampling conversion device; the current sampling device is connected to the sampling conversion device, and the sampling conversion device is connected to the processor;

[0010] The power supply module includes a main power supply, an auxiliary power supply, and a backup power supply; the main power supply takes power through the current sampling device to supply power to the processor; the auxiliary power supply is used to assist the main power supply in supplying power to the processor; the backup power supply is used to supply power to the processor when the main power supply and the auxiliary power supply stop supplying power.

[0011] Preferably, for the intelligent low-voltage controller, the current sampling device includes multiple groups of current samplers; each current sampler includes: a filtering capacitor and a sampling resistor; the filtering capacitor is connected in parallel with the sampling resistor; both ends of the sampling resistor are respectively connected to the sampling conversion device. Further, during normal use, the preferred number of groups of current samplers in the current sampling device is 4 groups.

[0012] Preferably, for the intelligent low-voltage controller, the main power supply includes: a comparator, a first rectifier, a switching tube, an energy storage capacitor, and a first isolator; the input end of the comparator is connected to one group of the multiple groups of current samplers, and the output end is connected to the base of the switching tube; the first rectifier is connected to the current sampler connected to the comparator; the collector of the switching tube is connected to the first rectifier, and the emitter is connected to the first isolator; one end of the energy storage capacitor is connected to the first rectifier, and the other end is connected to the first isolator; the first isolator is connected to the processor.

[0013] Preferably, for the intelligent low-voltage controller, the auxiliary power supply includes: a step-down transformer, a second rectifier, and a second isolator; both output ends of the step-down transformer are connected to the second rectifier; the second rectifier is connected to the second isolator; the second isolator is connected to the processor.

[0014] Preferably, for the intelligent low-voltage controller, the backup power supply is a super capacitor, and one end of the super capacitor is connected to the second rectifier, and the other end is connected to the second isolator.

[0015] Preferably, for the intelligent low-voltage controller, the communication module includes a carrier communicator, a wireless communicator, a Bluetooth communicator, and an RS485 communicator.

[0016] Preferably, the switching tube is a triode, and it is for the conventional use of the switching function of the triode.

[0017] Preferably, both the first rectifier and the second rectifier are rectifier diodes.

[0018] Preferably, both the first isolator and the second isolator are isolation diodes.

[0019] A low-voltage switch control system includes the intelligent low-voltage controller and a circuit breaker; the circuit breaker includes a switch contact, a potential taken from the upper port, and a current mutual inductance device at the lower port; the potential taken from the upper port and the current mutual inductance device at the lower port are respectively located at the upper and lower ports of the switch contact;

[0020] The current mutual inductance device at the lower port is connected to the current sampling device; the potential taken from the upper port is connected to the auxiliary power supply.

[0021] Preferably, in the low-voltage switch control system, the current mutual inductance device at the lower port includes multiple groups of current transformers; multiple groups of the current transformers are respectively connected to the current samplers in the current sampling device. Preferably, in the current mutual inductance device, the number of groups of the current transformers is 4 groups.

[0022] Preferably, in the low-voltage switch control system, the circuit breaker further includes multiple voltage transformers and a tripping device; the tripping device is used to drive and detect the on / off of the line switch and is connected to the processor in the intelligent low-voltage controller; multiple voltage transformers are all connected to the sampling conversion device in the intelligent low-voltage controller.

[0023] A low-voltage switch control device includes a body and the low-voltage switch control system; the external interfaces of the circuit breaker and the intelligent low-voltage controller in the low-voltage switch control system are both standard jacks, which are convenient for plugging and unplugging.

[0024] Compared with the prior art, an intelligent low-voltage controller, a low-voltage switch control system and a device provided by the present invention have the following effects compared with the prior art:

[0025] 1. The secondary part of the switch adopts a modular design, supports hot plugging, and is convenient for maintenance;

[0026] 2. Adopt a CT bootstrap switching circuit with an automatic switching function, and the load resistance of the sampling circuit remains constant within the normal load range of the line current, effectively improving the sampling accuracy;

[0027] 3. The switch internally integrates an auxiliary power supply and uses a super capacitor as a backup power supply. After the switch is powered off, power-off event reporting and fault information uploading are carried out. Description of the Drawings

[0028] Figure 1 is the structural block diagram of the intelligent low-voltage controller provided by the present invention;

[0029] Figure 2 is the schematic diagram of the low-voltage switch system provided by the present invention;

[0030] Figure 3 is the circuit diagram of the low-voltage switch system in Embodiment 2 provided by the present invention;

[0031] Figure 4 is the structural diagram of the low-voltage switch control device in Embodiment 3 provided by the present invention. Detailed Embodiments

[0032] To make the objectives, technical solutions and effects of the present invention clearer and more definite, the following further describes the present invention in detail with reference to the accompanying drawings and by way of examples. It should be understood that the specific examples described herein are only used to explain the present invention and are not used to limit the present invention.

[0033] Embodiment 1

[0034] Please refer to Figures 1 - 3 , the present invention provides an intelligent low-voltage controller, including a processor 1, a current sampling module 2, a communication module 3 and a power supply module 4; the current sampling module 2, the communication module 3 and the power supply module 4 are respectively connected to the processor 1; the processor 1 can be a commonly used processor 1 in the art, including but not limited to a microprocessor D8 and a central processing unit, and the present invention does not make specific limitations;

[0035] The current sampling module 2 includes a current sampling device 21 and a sampling conversion device 22; the current sampling device 21 is connected to the sampling conversion device 22, and the sampling conversion device 22 is connected to the processor 1; the sampling conversion device 22 is preferably an analog-to-digital converter D7, and the selection of the analog-to-digital converter is not specifically limited by the present invention and is a commonly used device in the art;

[0036] The power supply module 4 includes a main power supply 41, an auxiliary power supply 42 and a backup power supply 43; the main power supply 41 takes power through the current sampling device 21 to supply power to the processor 1; the auxiliary power supply 42 is used to assist the main power supply 41 to supply power to the processor 1; the backup power supply 43 is used to supply power to the processor 1 when the main power supply 41 and the auxiliary power supply 42 stop supplying power.

[0037] As a preferred solution, in this embodiment, the current sampling device 21 includes multiple groups of current samplers (not labeled); each current sampler includes a filter capacitor C1 and a sampling resistor R1; the filter capacitor C1 is connected in parallel with the sampling resistor R1; both ends of the sampling resistor R1 are respectively connected to the sampling conversion device 22.

[0038] As Figure 3 As shown, the controller auxiliary power supply 42 consists of a step-down transformer L1, a second rectifier D4, a super capacitor C2, and a second isolator D5. The auxiliary power supply 42 takes power from the upper port of the switch. The input end of the step-down transformer L1 is connected to the C-phase voltage and the N line at the upper port of the switch. The output end of the step-down transformer L1 is connected to the input end of the second rectifier D4. The output end of the second rectifier D4 is connected to the super capacitor C2. The super capacitor C2 is connected to the second isolator D5. The auxiliary power supply 42 supplies power to the processor D8 through the diode D5.

[0039] As a preferred solution, in this embodiment, the main power supply 41 includes a comparator D1, a first rectifier D2, a switching transistor D3, a storage capacitor C3, and a first isolator D6; the input end of the comparator D1 is connected to one group of the multiple groups of current samplers, and the output end is connected to the base of the switching transistor D3; the first rectifier D2 is connected to the current sampler connected to the comparator D1; the collector of the switching transistor D3 is connected to the first rectifier D2, and the emitter is connected to the positive pole of the first isolator D6; one end of the storage capacitor C3 is connected to the first rectifier D2, and the other end is connected to the positive pole of the first isolator D6; the negative pole of the first isolator D6 is connected to the processor 1. The first rectifier D2 is a bridge rectifier circuit, which is commonly used in the art and will not be specifically limited; the first isolator D6 is an isolation diode.

[0040] The current transformer bootstrap switching circuit of the intelligent low-voltage switch controller consists of a current transformer CT, a sampling resistor R1, a comparator D1, a first rectifier D2, a switching transistor D3, an energy storage capacitor C3, and a first isolator D6. The output terminal of the secondary winding of the current transformer CT is connected to a filter capacitor C1 and a sampling resistor R1. The current signal is converted into a voltage signal after passing through the sampling resistor R1 and is connected to the P1 and P2 ports of an analog-to-digital converter D7 to complete analog-to-digital conversion. The voltage signal is simultaneously connected to the comparator D1 and the first rectifier D2. The output circuit of the first rectifier D2 is controlled by the switching transistor D3. The output terminal of the switching transistor D3 is connected to the energy storage capacitor C3 and the first isolator D6. When a short-circuit fault occurs in the low-voltage distribution network, a large impact current (generally above 600A) is generated in the CT circuit. The comparator D1 operates to turn on the switching transistor D3. The impact current generated in the CT circuit is discharged and stored through the energy storage capacitor C3, stores energy for switch tripping, and supplies power to the processor D8. The first / second isolators D6 / D5 automatically switch the auxiliary power supply 42 and the main power supply 41 to supply power to the processor D8 and the tripping mechanism.

[0041] Please refer specifically to Figure 3 , in this embodiment, the measurement, protection, and power extraction share a current transformer. To reduce the impact of current transformer power extraction on measurement, a comparison switching circuit is designed. Based on a current value of 600A, when the current transformer detects that the current in the line is below 600A, the self-power extraction circuit of the current transformer does not work, and the load of the current transformer is constant, which can improve the measurement accuracy. When a short-circuit fault occurs, the comparison switching circuit automatically activates the current transformer power extraction circuit to provide power for the circuit breaker to trip.

[0042] When the line current is less than 600A, the current transformer is connected to the sampling circuit and will not be connected to the bootstrap circuit of the main power supply 41. The load of the current transformer is constant, and the measurement accuracy is high. It can be used for metering and measurement functions, thus realizing the functions of fault recording and topology-assisted analysis.

[0043] The voltage signal is simultaneously connected to the comparator D1 and the first rectifier D2. The output circuit of the first rectifier D2 is controlled by the switching transistor D3. The output terminal of the switching transistor D3 is connected to the energy storage capacitor C3 and the first isolator D6. When a short-circuit fault occurs in the low-voltage distribution network, a large impact current (generally above 600A) is generated in the current transformer circuit. The comparator D1 operates to turn on the switching transistor D3. The impact current generated in the CT circuit is discharged and stored through the energy storage capacitor C3, stores energy for switch tripping, and supplies power to the processor D8. The first / second isolators D6 / D5 automatically switch the auxiliary power supply 42 and the main power supply 41 to supply power to the processor 1 and the tripping mechanism.

[0044] As a preferred solution, in this embodiment, the auxiliary power supply 42 includes: a step-down transformer L1, a second rectifier D4, and a second isolator D5; both output terminals of the step-down transformer L1 are connected to the second rectifier D4; the second rectifier D4 is connected to the positive electrode of the second isolator D5; the negative electrode of the second isolator D5 is connected to the processor 1. The second rectifier D4 and the first rectifier D2 are the same rectifier, both being rectifier diodes and for conventional use, Figure 3 The rectifier diode in it is a bridge rectifier diode. Of course, when actually applying the technical solution provided by the present invention, it is not limited to using a bridge rectifier diode, and other rectifier devices can also be used; the second isolator D5 and the first isolator D6 are the same isolator, both being isolation diodes and for conventional use.

[0045] As a preferred solution, in this embodiment, the backup power supply 43 is a super capacitor C2. One end of the super capacitor C2 is connected to the second rectifier D4, and the other end is connected to the positive electrode of the second isolator D5.

[0046] Specifically, the power supply module 4 is composed of three-level power supplies: the main power supply 41, the auxiliary power supply 42, and the backup power supply 43.

[0047] The intelligent controller provided by the present invention is used in cooperation with a circuit breaker. The auxiliary power supply 42 takes the power from the upper port of the circuit breaker. When the circuit breaker is connected in 3P, the AB line voltage is used for power supply. When the circuit breaker is connected in 4P, the CN phase voltage is used for power supply, and the carrier module also uses single-phase carrier. After the circuit breaker protection trips, the auxiliary power supply 42 takes power from the upper port of the switch and can provide power for the circuit breaker. The backup power supply 43 is a super capacitor C2, and the selection of its capacitance can provide 1 minute of power for the communication system and the power for the circuit breaker to trip after the auxiliary power supply 42 is powered off.

[0048] The defect of using the super capacitor C2 as the circuit breaker trip is that the super capacitor C2 needs to be charged when the system is powered on for the first time. It is expected to take 5 minutes to fully charge, and the charging time is affected by the power and power consumption requirements of the power supply. This problem affects the trial power transmission in the substation area and meets the protection requirements for faults, and cannot trip in time.

[0049] The above problems can be solved by the cooperation of the main power supply 41 and the auxiliary power supply 42. When a short circuit occurs, a large current impact will be generated. The CT circuit accesses the measurement circuit to the CT bootstrap power supply through the comparison switching circuit, stores the power of the large current in the super capacitor C2, and provides energy for the circuit breaker to trip.

[0050] As a preferred solution, in this embodiment, the communication module 3 includes a carrier communicator, a wireless communicator, a Bluetooth communicator, and an RS485 communicator.

[0051] Example 2

[0052] Please refer to Figures 1 - 3 , the present invention also provides a low - voltage switch control system, including the intelligent low - voltage controller 20 and the circuit breaker 30 provided in Example 1; the circuit breaker 30 includes a switch contact, a potential taken from the upper port, and a current mutual induction device at the lower port; the potential taken from the upper port and the current mutual induction device at the lower port are respectively located at the upper and lower positions of the switch contact;

[0053] The current mutual induction device at the lower port is connected to the current sampling device 21; the potential taken from the upper port is connected to the auxiliary power supply 42.

[0054] As a preferred solution, in this embodiment, the current mutual induction device at the lower port includes multiple groups of current transformers; multiple groups of the current transformers are respectively connected to the current samplers in the current sampling device 21. Preferably, the number of the current transformers is 4 groups. Three current transformers (CTA, CTB, CTC in Figure 2 ) inside the circuit breaker body are respectively used to measure the line currents of three - phase electricity, and one residual current transformer (CTS in Figure 2 ) is selected and matched, applicable to current, and both can simultaneously realize the functions of power taking and measurement. The accuracy of the current transformer is 0.01 level.

[0055] As a preferred solution, in this embodiment, the circuit breaker further includes multiple voltage transformers and a tripping device; the tripping device is used to drive and detect the on - off of the line switch and is connected to the processor 1 in the intelligent low - voltage controller; multiple voltage transformers are all connected to the sampling conversion device 22 in the intelligent low - voltage controller. When the circuit breaker is connected to a four - wire three - phase power grid, the voltage signals detected by the multiple voltage transformers are UA, UB, and UC respectively.

[0056] The voltage signals UA, UB, and UC are connected to the P3, P4, and P5 ports of the analog - to - digital converter D7 to complete analog - to - digital conversion. After the voltage and current signals are subjected to analog - to - digital conversion, the data is connected to the processor D8. The processor D8 performs corresponding calculations according to the sampled voltage and current data to achieve short - circuit protection. The corresponding calculations performed here are common steps in the art, and the present invention does not make specific limitations.

[0057] Example 3

[0058] Please refer to Figure 4, the present invention also provides a low-voltage switch control device, including a body 10 and the low-voltage switch control system provided in Embodiment 2; the external interfaces of the circuit breaker and the intelligent low-voltage controller in the low-voltage switch control system are both standard jacks, which are convenient for plugging and unplugging. The intelligent low-voltage switch controller adopts a modular design, uses standardized hardware interfaces and structures, and realizes the function of hot plugging. The controller can be flexibly integrated into low-voltage molded case circuit breakers and residual current protective circuit breakers to form intelligent switch products.

[0059] It can be understood that for those of ordinary skill in the art, equivalent substitutions or changes can be made according to the technical solutions and inventive concepts of the present invention, and all such changes or substitutions should fall within the protection scope of the claims appended to the present invention.

Claims

1. An intelligent low-voltage controller, characterized in that, It includes a processor, a current sampling module, a communication module, and a power supply module; the current sampling module, the communication module, and the power supply module are respectively connected to the processor; The current sampling module includes a current sampling device and a sampling conversion device; the current sampling device is connected to the sampling conversion device, and the sampling conversion device is connected to the processor; The current sampling device includes multiple groups of current samplers; Each current sampler includes: a filtering capacitor and a sampling resistor; the filtering capacitor is connected in parallel with the sampling resistor; both ends of the sampling resistor are respectively connected to the sampling conversion device; The power supply module includes a main power supply, an auxiliary power supply, and a backup power supply; the main power supply takes power through the current sampling device to supply power to the processor; the auxiliary power supply is used to assist the main power supply in supplying power to the processor; the backup power supply is used to supply power to the processor when the main power supply and the auxiliary power supply stop supplying power; the main power supply includes: a comparator, a first rectifier, a switching transistor, an energy storage capacitor, and a first isolator; the input end of the comparator is connected to one group of the multiple groups of current samplers, and the output end is connected to the base of the switching transistor; the first rectifier is connected to the current sampler connected to the comparator; the collector of the switching transistor is connected to the first rectifier, and the emitter is connected to the first isolator; one end of the energy storage capacitor is connected to the first rectifier, and the other end is connected to the positive pole of the first isolator; the first isolator is connected to the processor; the first rectifier is a bridge rectifier circuit.

2. The intelligent low-voltage controller according to claim 1, characterized in that, The auxiliary power supply includes: a step-down transformer, a second rectifier, and a second isolator; both output ends of the step-down transformer are connected to the second rectifier; the second rectifier is connected to the second isolator; the second isolator is connected to the processor.

3. The intelligent low-voltage controller according to claim 2, characterized in that, The backup power supply is a super capacitor, and one end of the super capacitor is connected to the second rectifier, and the other end is connected to the second isolator.

4. The intelligent low-voltage controller according to claim 1, characterized in that, The communication module includes a carrier communicator, a wireless communicator, a Bluetooth communicator, and an RS485 communicator.

5. A low-voltage switch control system, characterized in that, It includes the intelligent low-voltage controller according to any one of claims 1-4 and a circuit breaker; the circuit breaker includes a switch contact, an upper-port power-taking potential, and a lower-port current mutual induction device; the upper-port power-taking potential and the lower-port current mutual induction device are respectively located at the upper and lower ports of the switch contact; the lower-port current mutual induction device is connected to the current sampling device; the upper-port power-taking potential is connected to the auxiliary power supply.

6. The low-voltage switch control system according to claim 5, characterized in that, The lower-port current mutual induction device includes multiple groups of current transformers; multiple groups of the current transformers are respectively connected to the current samplers in the current sampling device.

7. The low-voltage switch control system according to claim 5, characterized in that, The circuit breaker further includes multiple voltage transformers and a tripping device; the tripping device is used to drive and detect the on-off of the line switch and is connected to the processor in the intelligent low-voltage controller; multiple voltage transformers are all connected to the sampling conversion device in the intelligent low-voltage controller.

8. A low-voltage switch control device, characterized in that, It includes a main body and the low-voltage switch control system described in any one of claims 5-7; the external interfaces of the circuit breaker and the intelligent low-voltage controller in the low-voltage switch control system are both standard jacks.

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