Power cost control active-to-passive control system conversion circuit, converter and wiring method

Abstract

The invention discloses a power cost control active-to-passive control conversion circuit, a converter and a wiring method, and relates to the technical field of power cost control. The control conversion circuit comprises an analog-to-digital conversion unit, an isolation unit, a delay unit, a trigger unit and an output unit, the control conversion circuit is connected in series in a control loop between the intelligent electric energy meter and the circuit breaker, and an alternating current control signal sent by the intelligent electric energy meter is converted into a passive contact to be output through the control conversion circuit. Therefore, switching-on and switching-off control of the circuit breaker is realized, and the problems that a protection device cannot be additionally arranged in an active output mode and cost control of a simple circuit breaker containing high-supply and low-metering users cannot be realized are solved.

Description

Technical Field

[0001] This invention relates to the field of power cost control technology, and in particular to a control conversion circuit, converter, and wiring method for active-to-passive power cost control. Background Technology

[0002] As a key component of power system automation management, the prepaid control function of smart meters traditionally employs an active output method (AC220V control signal) to control the opening and closing of circuit breakers. However, this method has significant limitations in practical applications, specifically in the following aspects: (1) The control signal adopts the AC220V voltage level, which is not matched with the potential of the low-voltage control circuit (such as DC24V), which can easily cause electric shock risk to the operator, and conflict with the interface of other intelligent devices (such as PLC, sensors), increasing the difficulty of system integration; (2) The output impedance is relatively large, with an initial measured value of 100. When transmitting signals over long distances, the signal is susceptible to electromagnetic interference, resulting in severe signal attenuation and weak resistance to electromagnetic interference, which affects the control effect.

[0003] (3) The active output has insufficient load capacity and cannot directly drive standard relays. An additional amplifier circuit is required, which increases the complexity of the system and the cost. The number of circuit nodes increases the probability of failure. In particular, in complex scenarios such as photovoltaic grid connection and multiple power supply switching, it is difficult to achieve a fast response of the circuit breaker.

[0004] (4) For users who adopt "high-voltage supply and low-voltage metering", their power distribution system is usually equipped with simple circuit breakers. Traditional active output methods are incompatible with protection devices (such as overcurrent protection and leakage protection), resulting in the circuit breaker lacking fault protection capabilities and posing a risk of over-level tripping.

[0005] In summary, while the traditional active output method of smart meters has achieved cost control to a certain extent, it has certain safety risks. Furthermore, for users with "high supply and low metering," it is impossible to install protection devices on circuit breakers, making it difficult to achieve effective cost control. Summary of the Invention

[0006] This invention provides an active-to-passive power fee control conversion circuit, converter, and wiring method to solve the problem that simple circuit breakers in active output mode cannot be equipped with protection devices, making it difficult to achieve effective fee control for "high supply, low metering" users.

[0007] This invention is achieved through the following technical solution: In a first aspect, the present invention provides a control conversion circuit for active-to-passive conversion of electricity prepayment control, wherein the control conversion circuit is connected in series in the control loop of a smart meter and a circuit breaker, and the control conversion circuit includes: An analog-to-digital converter is used to receive the active prepaid control signal from the smart meter and convert it into a digital control signal; An isolation unit is used to isolate the digital control signals; The delay unit is used to delay the isolated digital control signal; The triggering unit is used to parse the digital control signal, determine the control intention of the smart meter based on the parsing result, and generate the intention control command; The output unit is used to receive the intention control command and control the closing circuit or opening circuit of the circuit breaker to operate according to the intention control command.

[0008] In the above technical solution of the present invention, the AC control signal issued by the smart meter is converted into a passive contact output by combining digital-to-analog conversion, isolation, delay, triggering and output units, thereby controlling the closing or opening circuit of the circuit breaker and realizing the opening and closing control of the circuit breaker. The system comprises several components: an analog-to-digital conversion unit (ADC) first receives the active prepaid control signal from the smart meter and converts it into a digital signal, effectively improving the accuracy and anti-interference capability of the control signal; an isolation unit then isolates the digital signal, enhancing the system's stability and security and preventing circuit breaker malfunctions caused by external interference signals; a delay unit, upon receiving the isolated signal, performs a delay to avoid circuit breaker malfunctions caused by transient low voltage in the power grid, ensuring the stability of power supply to users; a trigger unit parses the signal from the delay unit, calculates and analyzes the smart meter's control intent (such as closing or opening), and sends corresponding control commands to the output unit; finally, the output unit, upon receiving the control command from the trigger unit, executes the corresponding operation, directly controlling the circuit breaker's opening and closing circuits via passive contacts, ensuring the accurate execution of the prepaid control function and avoiding the insufficient load-carrying capacity problem that may exist in traditional active output methods.

[0009] In some implementations, the isolation unit employs an optocoupler isolator.

[0010] In some implementations, the analog-to-digital converter (ADC) converts the active fee control signal into a level signal based on a signal voltage threshold. When the active fee control signal is greater than or equal to the signal voltage threshold, the digital control signal output by the ADC is a high-level signal; when the active fee control signal is less than the signal voltage threshold, the digital control signal output by the ADC is a low-level signal.

[0011] In some implementations, the intent control command includes a closing control command and a opening control command; when the digital control signal is high, the triggering unit parses the control intent of the smart meter as closing and generates a closing control command; when the digital control signal is low, the triggering unit parses the control intent of the smart meter as opening and generates an opening control command.

[0012] In some embodiments, the output unit is composed of a relay, the normally closed contact of which is connected in series with the closing circuit of the circuit breaker, and the normally open contact of which is connected in series with the opening circuit of the circuit breaker.

[0013] In some implementations, when the received intended control command is a closing control command, the output unit controls the normally closed contact of the relay to close and the normally open contact to open, so as to connect the closing circuit; when the received intended control command is a opening control command, the output unit controls the normally closed contact of the electrical appliance to open and the normally open contact to close, so as to connect the opening circuit.

[0014] A second aspect of the present invention provides a power prepaid control active-to-passive control converter, comprising a protective housing and a power prepaid control active-to-passive control conversion circuit as described in any of the first aspects of the present invention; the control converter circuit is disposed inside the protective housing, and the protective housing is provided with wiring terminals, the wiring terminals including normally closed contacts, normally open contacts, prepaid control contacts and power signal contacts.

[0015] In some implementations, the output unit uses a rail-mounted relay with a combination of normally open and normally closed contacts; the external dimensions of the protective housing are compatible with the installation space of low-voltage circuit breakers.

[0016] In some embodiments, the protective housing has a heat dissipation groove on the side away from the wiring terminals.

[0017] A third aspect of the present invention provides a wiring method for an active-to-passive power prepaid control converter as described in any one of the first aspects of the present invention, the wiring method comprising: Connect the normally closed contact of the converter in series with the circuit breaker's tripping circuit; The normally open contact of the converter is connected in series with the closing circuit of the circuit breaker; Connect the converter's prepaid control contacts to the signal output terminal of the smart meter's active prepaid control signal; Connect the converter's power signal contacts to the AC power supply via an air switch.

[0018] Compared with the prior art, the present invention has the following advantages and beneficial effects: By combining an analog-to-digital conversion unit, an isolation unit, a delay unit, a trigger unit, an output unit, and a DC power supply, this converter successfully converts the AC control signal emitted by the smart energy meter into a passive contact output, thereby realizing the opening and closing control of the circuit breaker. This solves the problem of not being able to install protection devices under the active output mode and realizing the cost control of simple circuit breakers with high supply and low metering users. The active-to-passive converter for prepaid electricity control has advantages such as strong anti-interference capability, small size, and low power consumption. It not only solves the technical problems existing in the traditional active output method, but also provides a strong guarantee for the safe and efficient operation of the power prepaid electricity control system through flexible access methods and reliable performance. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In the drawings: Figure 1 This is a structural diagram of an active-to-passive power fee control conversion circuit proposed in an embodiment of the present invention; Figure 2 This is a schematic diagram of signal processing for an active-to-passive power fee control conversion circuit proposed in an embodiment of the present invention; Figure 3 This is a circuit diagram of an embodiment of the present invention that proposes applying an active-to-passive power fee control conversion circuit to a circuit breaker control loop; Figure 4 This is a schematic diagram of a protective housing for an active-to-passive power fee control converter according to an embodiment of the present invention; Figure 5 This is a wiring diagram of an active-to-passive power fee control converter proposed in an embodiment of the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0021] It should be noted that the terms "comprising" and "having" and any variations thereof in the specification, claims, and accompanying drawings of this invention are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to other steps or units inherent in the device.

[0022] The terminology used in the various embodiments of the invention is for the purpose of describing particular embodiments only and is not intended to limit the various embodiments of the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which the various embodiments of the invention pertain. The terms (such as those defined in commonly used dictionaries) are to be interpreted as having the same meaning as in the context of the relevant technical field and are not to be interpreted as having an idealized or overly formal meaning, unless clearly defined in the various embodiments of the invention.

[0023] Embodiments of this invention provide an active-to-passive power prepayment control conversion circuit, converter, and wiring method. Addressing the issue that some smart meters use active output prepayment control methods, which cannot accommodate circuit breaker protection devices, and the problem of effective prepayment control for "high-supply, low-metering" users, this invention's conversion circuit transforms the AC control signals emitted by the smart meter into passive contact outputs, thereby achieving control over the opening and closing of the circuit breaker. This technological breakthrough not only solves existing technical problems but also improves the reliability and security of prepayment control functions, providing strong support for the widespread application of smart meters.

[0024] Please see Figure 1-2 , Figure 1 The diagram shown is a structural diagram of an active-to-passive power fee control conversion circuit according to an embodiment of the present invention. The active-to-passive power fee control conversion circuit includes an analog-to-digital conversion unit 1, an isolation unit 2, a delay unit 3, a trigger unit 4, and an output unit 5. Figure 2 The diagram shows the signal processing of the active-to-passive control conversion circuit for electricity prepaid control. Analog-to-digital converter 1 converts the active prepaid control signal into a digital control signal. Isolation unit 2 isolates the digital control signal. Delay unit 3 delays the isolated digital control signal. Trigger unit 4 parses the digital control signal, determines the smart meter's control intent based on the parsing result, and generates the intent control command. Output unit 5 receives the intent control command and controls the closing or opening circuit of the circuit breaker according to the intent control command.

[0025] The analog-to-digital conversion unit 1 employs an ADC conversion circuit. After being connected to the active prepaid control output terminal of the smart meter, it acquires the active prepaid control signal from the smart meter and converts it into a digital control signal. The active prepaid control signal is typically a 220V AC signal, which is converted into a digital I / O signal for output via a D / A conversion circuit. This conversion process is based on the signal's voltage threshold, effectively improving the accuracy and anti-interference capability of the control signal.

[0026] Isolation unit 2 employs isolation circuitry to isolate digital control signals, achieving electrical isolation between analog-to-digital conversion unit 1 and subsequent units. This design enhances system stability and security, preventing circuit breaker malfunctions that may be caused by external interference signals. The isolation unit can utilize appropriate isolation technologies as needed, such as electromagnetic isolation, inductive isolation, fiber optic isolation, or optocoupler isolation.

[0027] In this implementation, an optocoupler isolator is preferably used as the isolation unit. The insulation resistance between the input and output sides of the optocoupler can reach [value missing]. The breakdown voltage is typically greater than 2500V, effectively isolating interference signals such as high voltage and surges, preventing noise in the active signal of the smart meter (such as transient voltage fluctuations in the power grid and electromagnetic interference) from being conducted to the circuit breaker control circuit, thus preventing malfunctions. When a transient overvoltage occurs in the power grid, the isolation gap of the optocoupler can block the impact of voltage surges on subsequent circuits, ensuring the stable operation of the triggering unit and the output unit.

[0028] Delay unit 3 is located after the isolation unit. After receiving the isolated signal, it performs a certain delay processing on it. The purpose of this step is to avoid circuit breaker malfunctions caused by transient low voltage in the power grid, thereby ensuring the stability of power supply to users.

[0029] The trigger unit 4, located after the delay unit, is responsible for parsing the signals sent from the delay unit. It calculates and analyzes the control intent of the smart meter (such as closing or opening the circuit breaker) and sends this intent command to the output unit 5. If the active prepaid control signal output by the smart meter is a high-voltage signal, after analog-to-digital conversion, isolation, and delay processing, the trigger unit 4, based on the voltage parsing of the received digital control signal, determines that the active prepaid control signal output by the smart meter is high-voltage, confirming the control intent as closing. It then generates a corresponding control command to control the output unit to perform the circuit breaker closing operation. Conversely, if the voltage parsing of the received digital control signal indicates that the active prepaid control signal output by the smart meter is low-voltage, confirming the control intent as opening the circuit breaker, it generates a corresponding control signal to control the output unit to perform the circuit breaker opening operation. The trigger unit 4 can be implemented using technologies such as a comparator circuit, a programmable logic device, or an MCU.

[0030] Output unit 5 is connected to the circuit breaker. After receiving the command from the trigger unit, output unit 5 quickly executes the corresponding operation, directly controlling the opening and closing of the circuit breaker in the form of passive contacts. This process ensures the accurate execution of the fee control function and avoids problems such as insufficient load-carrying capacity that may exist in traditional active output methods. When the smart meter shows a balance, the fee control output is a high-voltage signal. At this time, the relay of the output unit does not operate, and the circuit breaker remains in its current state. When the smart meter is in arrears, the fee control output is a low-voltage or no-voltage signal. At this time, the relay of the output unit operates, realizing the circuit breaker's opening operation according to the control intention, thereby achieving the purpose of fee control.

[0031] During operation, the control conversion circuit is connected in series in the control loop between the smart meter and the circuit breaker. The control conversion circuit converts the AC control signal sent by the smart meter into a passive contact output, thereby realizing the opening and closing control of the circuit breaker. This solves the problem that protection devices cannot be installed under the active output mode and the problem of cost control for users with high supply and low metering of simple circuit breakers.

[0032] Furthermore, the power fee control active-to-passive conversion circuit also includes a DC power supply 6, which converts 220V AC voltage to 5V DC voltage to power the various modules in the control conversion circuit.

[0033] In one implementation, the analog-to-digital converter 1 converts the active fee control signal into a level signal based on a signal voltage threshold. Specifically, when the active fee control signal is greater than or equal to the signal voltage threshold, the digital control signal output by the analog-to-digital converter is high; when the active fee control signal is less than the signal voltage threshold, the digital control signal output by the analog-to-digital converter is low. For example, if the active fee control signal is greater than AC120V, the output is 0; if it is less than AC120V, the output is 1.

[0034] Furthermore, the intent control commands include closing control commands and opening control commands. When the digital control signal is high, trigger unit 4 parses the control intent of the smart meter as closing and generates a closing control command; when the digital control signal is low, trigger unit 4 parses the control intent of the smart meter as opening and generates an opening control command.

[0035] In one embodiment, the output unit 5 is composed of a relay, with the normally closed contact of the relay connected in series with the closing circuit of the circuit breaker, and the normally open contact of the relay connected in series with the opening circuit of the circuit breaker.

[0036] When the received intention control command is a closing control command, the output unit 5 controls the normally closed contact of the relay to close and the normally open contact to open, so as to connect the closing circuit; when the received intention control command is a tripping control command, the output unit 5 controls the normally closed contact of the relay to open and the normally open contact to close, so as to connect the tripping circuit.

[0037] Please see Figure 3 , Figure 3The diagram shows the circuit schematic of applying the active-to-passive power prepaid control conversion circuit to the circuit breaker control loop, which is equipped with a protection device. For the closing circuit connection method, by connecting the normally closed contact of the output relay of the output unit in series with the circuit breaker's closing circuit, an additional circuit breaker closing condition can be added. The advantage of this method is that it allows for closing judgment under more complex conditions (such as voltage on the photovoltaic line, voltagelessness on the photovoltaic side, etc.), thereby effectively preventing potential risks such as asynchronous parallel operation. The smart meter is only responsible for enabling the prepaid control condition, while the specific circuit breaker closing operation is determined by the protection device or on-site operators based on real-time conditions, which greatly improves operational safety and flexibility.

[0038] Furthermore, during equipment maintenance, because the normally closed contact of the converter is connected in series in the closing circuit, even if the converter itself is in an active state, i.e. the normally closed contact of the relay is closed, the auxiliary normally closed contact of the circuit breaker is open at this time, which will not cause the circuit breaker to close unexpectedly, thus avoiding potential safety threats during the opening and closing of disconnectors or equipment maintenance operations.

[0039] For the tripping circuit connection method, directly connecting the normally open contact of the output relay of the output unit to the tripping circuit of the circuit breaker is a direct and effective means of cutting off power in case of user arrears. This method ensures that users with arrears can have their power cut off in a timely manner, prompting users to purchase electricity promptly, thereby maintaining the fairness and sustainability of power supply.

[0040] In summary, by combining a digital-to-analog conversion unit, an isolation unit, a delay unit, a trigger unit, an output unit, and a DC power supply, this converter successfully converts the AC control signal emitted by the smart energy meter into a passive contact output, thereby realizing the opening and closing control of the circuit breaker. This solves the problem of not being able to install protection devices under active output mode and the cost control problem of simple circuit breakers with high supply and low metering users.

[0041] Embodiments of the present invention also provide an active-to-passive power prepayment control converter, which includes a protective housing, such as... Figure 4 As shown, the active-to-passive control conversion circuit is as described in any of the above embodiments of the present invention. The active-to-passive control conversion circuit is disposed inside the protective housing. The protective housing is provided with wiring terminals, including normally closed contacts, normally open contacts, control contacts, and power signal contacts.

[0042] Furthermore, the output unit 5 of the control conversion circuit adopts a rail-mounted relay with a combination of normally open and normally closed contacts; the outer dimensions of the protective housing are compatible with the installation space of low-voltage circuit breakers.

[0043] The converter was ultimately designed to be the size of a 1.5 horsepower low-voltage rail-mounted circuit breaker (90×45×25mm). This design fully considers the convenience and compatibility of on-site installation. It can be easily accommodated in both distribution boxes and meter boxes without the need for large-scale modifications to existing equipment, which greatly reduces installation costs and difficulties.

[0044] Furthermore, the protective housing has a heat dissipation groove on the side away from the wiring terminals.

[0045] Embodiments of the present invention also provide a wiring method for an active-to-passive power prepaid control converter, such as... Figure 5 As shown, it includes: S1, connect the normally closed contact of the converter in series with the circuit breaker's tripping circuit.

[0046] S2, connect the normally open contact of the converter in series with the closing circuit of the circuit breaker.

[0047] S3 connects the converter's prepaid control contacts to the signal output terminal of the smart meter's active prepaid control signal.

[0048] S4 connects the converter's power signal contacts to the AC power supply via an air switch.

[0049] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A control conversion circuit for power fee control from active to passive, characterized in that, The control conversion circuit is connected in series in the control loop of the smart meter and the circuit breaker. The control conversion circuit includes: An analog-to-digital converter is used to receive the active prepaid control signal from the smart meter and convert it into a digital control signal; An isolation unit is used to isolate the digital control signals. The delay unit is used to delay the isolated digital control signal; The triggering unit is used to parse the digital control signal, determine the control intention of the smart meter based on the parsing result, and generate the intention control command; The output unit is used to receive the intention control command and control the closing circuit or opening circuit of the circuit breaker to operate according to the intention control command.

2. The control conversion circuit for active to passive power fee control according to claim 1, characterized in that, The isolation unit uses an optocoupler isolator.

3. The control conversion circuit for active-to-passive power fee control according to claim 1, characterized in that, The analog-to-digital conversion unit converts the active fee control signal into a level signal based on a signal voltage threshold. When the active fee control signal is greater than or equal to the signal voltage threshold, the digital control signal output by the analog-to-digital conversion unit is a high-level signal. When the active fee control signal is less than the signal voltage threshold, the digital control signal output by the analog-to-digital conversion unit is a low-level signal.

4. The power fee control active-to-passive conversion control circuit according to claim 3, characterized in that, The intent control commands include closing control commands and opening control commands; when the digital control signal is high, the triggering unit parses the control intent of the smart meter as closing and generates a closing control command; when the digital control signal is low, the triggering unit parses the control intent of the smart meter as opening and generates an opening control command.

5. The control conversion circuit for active to passive power fee control according to claim 1, characterized in that, The output unit is composed of a relay, the normally closed contact of the relay is connected in series with the closing circuit of the circuit breaker, and the normally open contact of the relay is connected in series with the opening circuit of the circuit breaker.

6. The control conversion circuit for active-to-passive power fee control according to claim 5, characterized in that, When the received intention control command is a closing control command, the output unit controls the normally closed contact of the relay to close and the normally open contact to open, so as to connect the closing circuit; when the received intention control command is a tripping control command, the output unit controls the normally closed contact of the electrical appliance to open and the normally open contact to close, so as to connect the tripping circuit.

7. A power prepaid control active-to-passive converter, characterized in that, It includes a protective housing and a power prepaid control active-to-passive conversion control circuit as described in any one of claims 1-6; the control conversion circuit is disposed inside the protective housing, and the protective housing is provided with wiring terminals, the wiring terminals including normally closed contacts, normally open contacts, prepaid control contacts and power signal contacts.

8. The power prepaid control active-to-passive converter according to claim 7, characterized in that, The output unit uses a rail-mounted relay with normally open and normally closed contact types; the outer dimensions of the protective housing are compatible with the installation space of low-voltage circuit breakers.

9. The power prepaid control active-to-passive converter according to claim 7 or 8, characterized in that, The protective housing has a heat dissipation groove on the side away from the wiring terminals.

10. A wiring method for the power prepaid control active-to-passive converter according to any one of claims 7-9, characterized in that, The wiring method includes: Connect the normally closed contact of the converter in series with the circuit breaker's tripping circuit; Connect the normally open contact of the converter in series with the closing circuit of the circuit breaker; Connect the converter's prepaid control contacts to the signal output terminal of the smart meter's active prepaid control signal; Connect the converter's power signal contacts to the AC power supply via an air switch.

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