One-key linkage control circuit and control device of low-voltage automatic switch

Abstract

The utility model discloses a one-key linkage control circuit and a control device of a low-voltage automatic switch. The one-key linkage control circuit comprises a processor with an ARM framework, a voltage and current sampling circuit, a low-voltage automatic switch state acquisition circuit and a plurality of groups of relay output signal circuits. The control device is connected with a plurality of low-voltage automatic switches; the voltage and current sampling circuit is connected to the controller processor; the low-voltage automatic switch state acquisition circuit is connected to the controller processor. During operation, the control device detects voltage values and phases on two sides of the low-voltage automatic switch, current flowing through the low-voltage automatic switch and the state of the low-voltage automatic switch in real time. According to the utility model, voltage values and phase positions at two sides of the low-voltage automatic switch, current flowing through the low-voltage automatic switch and states of the low-voltage automatic switch are detected in real time; and the control device automatically judges whether the low-voltage automatic switch meets a'hot reversing 'or'cold reversing' condition and executes a command to perform opening and closing operations.

Description

Technical Field

[0001] The utility model relates to power distribution automation of a power grid, in particular to a one-button linkage control circuit and a control device for a low-voltage automatic switch. Background Art

[0002] In the typical design of the State Grid Corporation's distribution room, the distribution station / station has two main transformers running hand in hand in parallel, and the low-voltage side adopts a structure of two incoming line switches + one busbar interconnecting switch. During operation, the three switches need to be switched according to the situation.

[0003] To prevent misoperation, some stations have installed a "three locks, two keys" mechanism to prevent misoperation. However, the cumbersome operating procedures are inefficient when operating the switches, and "hot switching" (closing the busbar while both sides are energized) is impossible. Some stations lack this mechanism, resulting in a greater risk of misoperation.

[0004] Hot switching refers to the process of transferring power from one line to another within the power system, utilizing existing lines and equipment without interrupting the supply. This method provides users with an uninterrupted and stable power supply, significantly improving the reliability of the distribution network. This reduces the costs associated with power outages for users while streamlining operations for power supply companies.

[0005] Cold switching is a term for a power system switching operation, meaning the switching of load power during a power outage. This operation is typically performed to maintain grid stability and security. For example, when replacing or repairing electrical equipment, it is necessary to shut down the line, perform the necessary operations, and then restore power.

[0006] When the distribution station / room is operating normally, if one of the 10KV lines loses power for some reason, the low-voltage side load will need to be transferred to the backup power supply.

[0007] Furthermore, the dual-main transformer distribution room has three frame-type circuit breakers: one on the low-voltage side of each transformer and one on the bus tie. The opening or closing of these three frame-type circuit breakers determines the distribution room's power supply and operation mode, as well as the mode for power outages and maintenance. Adjusting the distribution room's operating mode requires operating switches, requiring on-site personnel to go to the switchgear and operate them one by one. Operating switches one by one takes a long time and can lead to accidents or power outages due to personnel misstepping, operating the wrong switch, or operating them in the wrong order.

[0008] In view of this, it is necessary to improve the circuit structure of traditional power distribution network. Utility Model Content

[0009] In view of the deficiencies in the prior art, the technical problem to be solved by the present invention is to provide a one-button linkage control circuit and control device for a low-voltage automatic switch. The purpose of designing the one-button linkage circuit is to issue an operation command with one button, so as to realize one-button linkage of the low-voltage automatic switch, operate multiple switches, prevent misoperation, and speed up the operation steps.

[0010] In order to solve the above technical problems, the present invention is implemented through the following scheme: a one-button linkage circuit of a low-voltage automatic switch of the present invention comprises:

[0011] A processor with ARM architecture is connected to multiple low-voltage automatic switches;

[0012] a voltage and current sampling circuit connected to the processor;

[0013] A low-voltage automatic switch state acquisition circuit is connected to the processor, and the low-voltage automatic switch state acquisition circuit collects the voltage value and phase on both sides of the low-voltage automatic switch, the current flowing through the low-voltage automatic switch, and the state of the low-voltage automatic switch in real time;

[0014] Multiple groups of relay output signal circuits, any group of relay output signal circuits in the multiple groups of relay output signal circuits are controlled by a processor, and each relay automatically controls the opening and closing of multiple switches in steps by receiving the processor signal.

[0015] Furthermore, the processor is a 32-bit single-chip microcomputer.

[0016] Furthermore, the voltage and current sampling circuit includes a current limiting circuit connected to a power supply, a voltage mutual inductance isolation circuit connected to the output end of the current limiting circuit, an operational amplifier conditioning circuit connected to the output end of the voltage mutual inductance isolation circuit, and a filter circuit connected to the output end of the operational amplifier conditioning circuit.

[0017] Furthermore, the low-voltage automatic switch status acquisition circuit includes a three-way switch connected to a processor. After the three-way switch is powered on, 12 phase voltages and 6 phase currents pass through the three-way switch. The processor samples the 12 phase voltages and 6 phase currents of the three-way switch at 32 points per cycle.

[0018] Furthermore, the low-voltage automatic switch state acquisition circuit is provided with an optocoupler isolation circuit.

[0019] Furthermore, the optical coupling isolation circuit is a circuit in which an optical coupling device is connected to the low-voltage automatic switch state acquisition circuit.

[0020] The utility model provides a control device, which comprises the one-key linkage circuit and is connected to a plurality of low-voltage automatic switches.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention detects the voltage value and phase on both sides of the switch, the current flowing through the switch, and the state of the switch in real time. When the switch is linked with a key command, it determines whether the switch is hot-reversed or cold-reversed, the load of the transformer, etc., and automatically performs the opening and closing of multiple switches in steps. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is the principle block diagram of the one-key linkage circuit of the utility model.

[0023] Figure 2 This is a circuit diagram of the processor U101 of the present invention.

[0024] Figure 3 This is a three-phase circuit connection structure diagram for accessing power supply of the utility model.

[0025] Figure 4 This is the operational amplifier conditioning circuit diagram of this utility model.

[0026] Figure 5 This is the filter circuit diagram of the utility model after connecting to the operational amplifier conditioning circuit.

[0027] Figure 6 This is the circuit diagram of the third processor U103 of the present invention.

[0028] Figure 7 This is the circuit diagram of the second processor U102 of the present invention.

[0029] Figure 8 This is the optocoupler circuit diagram of the utility model.

[0030] Figure 9 This is a circuit diagram of multiple relay groups of the utility model.

[0031] Markings in the accompanying drawings: voltage and current sampling circuit 1, low-voltage automatic switch status acquisition circuit 2, and loop-closing core phase relay 4. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more specific definition of the scope of protection of the present invention. Obviously, the embodiments described in the present invention are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0033] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0034] Example 1: The specific structure of the utility model is as follows:

[0035] Please refer to the attached Figure 1-9 The utility model discloses a one-button linkage circuit for a low-voltage automatic switch, comprising a processor with an ARM architecture, a voltage and current sampling circuit 1, a low-voltage automatic switch state acquisition circuit 2, and multiple relay output signal circuits.

[0036] The device is equipped with an ARM-based processor, connected to multiple low-voltage automatic switches. The processors are U101, U102, and U103, all 32-bit single-chip microcomputers. The STM32F051 processors are used for U101 and U103, while the STM32F091 processor is used for U102.

[0037] The voltage and current sampling circuit 1 is connected to the processor. The electrical input end of the current and voltage sampling circuit 1 is connected to a three-phase power supply, and a current limiting resistor is connected to the A phase circuit of the three-phase power supply. Figure 3 As shown. The three-phase power supply has 12 phase voltages, which are isolated by voltage transformers. Figure 3 As shown, Figure 3 Six sets of voltage transformers T301~T306 are set in the circuit. After the six sets of voltage transformers T301~T306 isolate the power supply, their output terminals are connected to the operational amplifier conditioning circuit, such as Figure 4 shown.

[0038] The voltage and current sampling circuit 1 includes a current limiting circuit connected to a power supply, a voltage mutual inductance isolation circuit connected to the output end of the current limiting circuit, an operational amplifier conditioning circuit connected to the output end of the voltage mutual inductance isolation circuit, and a filter circuit connected to the output end of the operational amplifier conditioning circuit.

[0039] The op amp conditioning circuit includes a first op amp and a first resistor. The inverting input of the first op amp is connected to the voltage terminal of the voltage transformer output, the non-inverting input of the first op amp is connected to the VREF terminal of the voltage transformer, and the first resistor is connected between the inverting input of the first op amp and the non-inverting input of the first op amp. The output of the first op amp is connected to a filter circuit. There are six sets of op amp conditioning circuits, connected one-to-one with the six sets of voltage transformers. Accordingly, the six op amp conditioning circuits are connected one-to-one with the six filter circuits.

[0040] like Figure 5 As shown, Figure 5This is a filter circuit. It includes a second resistor and a first capacitor. The first end of the second resistor is connected to the output of the first op amp, the second end of the second resistor is connected to a pin of processor U101 designated as ADC_IN, the first end of the second capacitor is connected to the second end of the second resistor, and the second end of the second capacitor is connected to DGND. This filter circuit is an RC filter circuit composed of a resistor and a capacitor, and performs a filtering function.

[0041] Phase voltage detection: The phase voltage is AC 220V, which passes through the current limiting resistor, isolated by the voltage transformer, and then passes through the operational amplifier conditioning circuit and the filtering circuit.

[0042] Current detection: The phase current is isolated by a 5A / 2.5mA current transformer and then passes through an op amp conditioning circuit and a filter circuit.

[0043] The processor samples the 12 phase voltages and 6 phase currents of the three switches in the distribution room at 32 points per cycle. The sampled values ​​are calculated using Fourier transform to obtain the effective value and phase of the voltage, the effective value of the current, and the related active power, reactive power, power factor, etc.

[0044] A low-voltage automatic switch state acquisition circuit 2 is connected to the processor. This circuit monitors the voltage and phase on both sides of the switch, the current flowing through the low-voltage automatic switch, and the state of the low-voltage automatic switch in real time. The circuit comprises a three-way low-voltage automatic switch connected to the processor. When powered on, the three low-voltage automatic switches pass 12 phase voltages and 6 phase currents. The processor samples these 12 phase voltages and 6 phase currents at 32 points per cycle. The circuit is equipped with an optocoupler isolation circuit. This optocoupler isolation circuit incorporates an optocoupler device within the circuit. The internal signal power is routed through the normally open passive contacts of the three low-voltage automatic switches, to the optocoupler for isolation, and then to the processor pins. The processor interrupts sampling and, after debounce processing, transmits the open / closed state of the low-voltage automatic switch.

[0045] Multiple groups of relay output signal circuits, any group of relay output signal circuits in the multiple groups of relay output signal circuits are controlled by a processor, and each relay automatically controls the opening and closing of multiple switches in steps by receiving the processor signal.

[0046] Logic Control: The processor monitors the voltage and phase on both sides of the switch, the current flowing through the switch, and the switch status in real time. When a one-touch switch linkage command is issued, it determines whether the switch is hot or cold, the transformer load, and other conditions, and automatically opens and closes multiple switches in a step-by-step manner.

[0047] As shown in Figure 9, Figure 9 This is the circuit diagram of multiple relay groups of the utility model. Figure 9 Six groups of relays are provided in the circuit breaker, which are respectively connected to 12 voltage switches, and the opening and closing actions are controlled by the processor 101.

[0048] The one-touch linkage circuitry of this low-voltage automatic switch is controlled via a touchscreen, allowing one-touch operation commands to be issued based on the operating mode. This allows multiple switches to be operated, preventing operational errors and expediting the process. The system monitors the voltage and phase on both sides of the switches, the current flowing through the switches, and the switch status in real time. When a one-touch linkage command is issued, it determines whether the switches are hot or cold, the transformer load, and other conditions, automatically opening and closing the multiple switches in a step-by-step manner.

[0049] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A one-button linkage circuit for a low-voltage automatic switch, characterized in that: include: A processor with ARM architecture is connected to multiple low-voltage automatic switches; A voltage and current sampling circuit (1) connected to the processor; A low-voltage automatic switch state acquisition circuit (2) is connected to the processor, and the low-voltage automatic switch state acquisition circuit (2) acquires the voltage value and phase on both sides of the low-voltage automatic switch, the current flowing through the low-voltage automatic switch, and the state of the low-voltage automatic switch in real time; Multiple groups of relay output signal circuits, any group of relay output signal circuits in the multiple groups of relay output signal circuits are controlled by a processor, and each relay automatically controls the opening and closing of multiple switches in steps by receiving the processor signal.

2. A one-button linkage circuit for a low-voltage automatic switch according to claim 1, characterized in that: The processor is a 32-bit single-chip microcomputer.

3. A one-button linkage circuit for a low-voltage automatic switch according to claim 1, characterized in that: The voltage and current sampling circuit (1) comprises a current limiting circuit connected to a power supply, a voltage mutual inductance isolation circuit connected to an output end of the current limiting circuit, an operational amplifier conditioning circuit connected to an output end of the voltage mutual inductance isolation circuit, and a filter circuit connected to an output end of the operational amplifier conditioning circuit.

4. A one-button linkage circuit for a low-voltage automatic switch according to claim 1, characterized in that: The low-voltage automatic switch state acquisition circuit (2) comprises a three-way switch connected to a processor, wherein 12 phase voltages and 6 phase currents pass through the three-way switch after power is turned on, and the processor samples the 12 phase voltages and 6 phase currents of the three-way switch at 32 points per cycle.

5. A one-button linkage circuit for a low-voltage automatic switch according to claim 4, characterized in that: The low-voltage automatic switch state acquisition circuit (2) is provided with an optical coupling isolation circuit.

6. A one-button linkage circuit for a low-voltage automatic switch according to claim 5, characterized in that: The optical coupling isolation circuit is a circuit in which an optical coupling device is connected to a low-voltage automatic switch state acquisition circuit (2).

7. A control device, characterized in that: The one-key linkage circuit comprises the one-key linkage circuit according to any one of claims 1 to 6, which is connected to multiple low-voltage automatic switches.

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