CN217882859U - Three-phase load balance adjusting device - Google Patents

Abstract

The utility model provides a three-phase load balance adjusting device, which comprises a three-phase switch, wherein the three-phase switch is constructed to respectively control the on-off of each phase of circuit according to the balance condition of three-phase load current in the circuit; and a three-phase line, each phase of the three-phase line is correspondingly connected with each switch of the three-phase switches, and the three-phase line is configured to carry out single-phase energization according to the opening and closing conditions of the three-phase switches; a detection mechanism connected to the three-phase line, the detection mechanism configured to detect a current condition in the three-phase line; the detection mechanism, the three-phase circuit and the three-phase switch are all installed at the front end of the user electric energy meter. The utility model discloses can solve the unbalanced problem of three-phase load.

Description

A three-phase load balance adjustment device

technical field

The utility model relates to the technical field of electric equipment, in particular to a three-phase load balance adjustment device.

Background technique

In recent years, with the rapid development of industrial and commercial enterprises, my country's social electricity consumption has continued to increase, and the masses of the people have become more and more dependent on electricity. In order to meet the increasing demand for electricity, a large number of single-phase loads have been added to the three-phase four-wire system on the low-voltage side of urban and rural distribution stations. However, these loads are unevenly distributed and the use time is uncertain, which brings great uncontrollability to the distribution area, and is prone to unbalanced three-phase loads. When the three-phase load is unbalanced, the loss of the distribution network will increase, which will reduce the utilization rate of electric energy and affect the safety of users' electricity consumption and system power supply.

Utility model content

In view of this, the embodiments of the present invention are dedicated to providing a three-phase load balance adjustment device, which can solve the problem of unbalanced three-phase loads.

According to one aspect of the present invention, the three-phase load balance adjustment device provided by an embodiment of the present invention includes: a three-phase switch, the three-phase switch is connected with the detection mechanism, and the three-phase switch is configured to The balance of the three-phase load current in the line, respectively controls the closing or disconnection of each phase line; for the three-phase line, each phase in the three-phase line is respectively connected to each switch in the three-phase switch , the three-phase line is configured to perform single-phase power supply according to the opening and closing of the three-phase switch; and a detection mechanism, the detection mechanism is connected to the three-phase line, and the detection mechanism is configured to detect the three-phase The current situation in the line; wherein, the detection mechanism, the three-phase line and the three-phase switch are all installed at the front end of the electric energy meter of the user.

The detection mechanism is used to detect the current condition of one phase of the three-phase line, and the power supply phase and the corresponding current magnitude can be obtained through the detection of the detection mechanism. Through the three-phase switch to control the connection and disconnection of the three-phase line, according to the balance of the three-phase load in the main line, the connection and disconnection of the three-phase line can be controlled, thereby adjusting the load of the three-phase load. At the same time, only one phase switch or one phase line is closed to prevent short circuit. The three-phase load balance adjustment device is connected in series to the front end of the user's electric energy meter, and is installed on the circuit between the secondary protection box and the user's electric energy meter. The power supply can be adjusted by the three-phase load balance adjustment device, and then flows into the user's electric energy meter. Targeted adjustments can be made to users, the use is more flexible, and the adjustment effect is more significant.

In one embodiment, the three-phase load balance adjustment device further includes: a three-phase indicator light, which is connected in parallel with the three-phase line, and the three-phase indicator light is configured to turn on when it is powered on to show A single-phase line that has been connected and powered in the current three-phase lines.

The three-phase indicator light is used to display which phase line is connected, which is convenient for the user to perform phase change operation. Through the three-phase indicator light, you can quickly know the on-off status of the three-phase line in the three-phase load balance adjustment device, helping users quickly adjust the three-phase load balance.

In an embodiment, the three-phase load balance adjustment device further includes: a protector connected in series with the three-phase line, and the protector is configured such that when the current value of the residual current is greater than a preset current value , breaking the bus line to protect the three-phase line; wherein, the residual current represents the current generated when the vector sum of the currents of each phase passing through the protector is not zero.

Protectors can include residual current action protectors, which are also known as leakage protectors, which are mainly used to provide protection against dangerous and potentially fatal electric shocks, and also for long-term continuous ground fault currents that cannot be operated by overcurrent protection appliances Provide protection against the resulting fire hazard. Installing residual current operating protectors in low-voltage power grids is an effective protective measure to prevent personal electric shocks, electrical fires, and electrical equipment damage.

In an embodiment, the three-phase load balance adjustment device further includes: three-phase buttons, each of the three-phase buttons is respectively connected to each of the three-phase switches, and the three-phase The button is configured to control the closing or opening of the three-phase switch; wherein, the three-phase button is controlled by a station manager.

The three-phase button corresponds to the control of the three-phase switch. The three-phase button can be controlled by the station manager, and the station manager directly controls the closing or opening of the three-phase switch through the three-phase button. That is to say, the three-phase load balance adjustment device is installed on the user side. When the three-phase imbalance occurs on the user side, it can be directly dealt with on site, and the phase with a lighter load can be switched for power supply. In the case of a large load deviation, it can be switched on site in time.

In an embodiment, the three-phase switch includes: an AC contactor, and the AC contactor is configured to be closed or disconnected according to an instruction of the three-phase button to connect a single-phase line.

Through the contact locking of the AC contactor, it can ensure that only one phase of the AC contactor is closed, thereby preventing the occurrence of a short circuit. Compared with the power electronic equipment, the mechanical equipment has stronger anti-interference ability and lower malfunction rate. Reliable power supply is ensured while the load is adjusted.

In one embodiment, the three-phase load balance adjustment device further includes: a switching mechanism, the switching mechanism is respectively connected to each phase switch in the three-phase switches, and the switching mechanism is configured to To balance the phase load current, switch any switch of the three-phase switches to a closed state or an open state.

The switching mechanism may include a processor and a controller, the processor is connected to the controller, and the processor is used to receive the power supply phase difference and the corresponding current magnitude detected by the detection mechanism, and judge whether the current line has a three-phase load current unbalanced condition.

In one embodiment, the detection mechanism includes: a transformer, the transformer is connected to the three-phase line, and the transformer is configured to reduce the current ratio in the three-phase line to detect the three-phase Current conditions in the lines; ammeters, the ammeters are respectively connected to the three-phase lines, and the ammeters are configured to detect the current conditions in the three-phase lines.

Transformers may include current transformers, which may convert large currents into small currents for measurement or protection systems. In the power supply line, the current difference ranges from a few amps to tens of thousands of amps, and the current in the line is relatively high. It is very dangerous to measure it directly. In order to facilitate the measurement of secondary instruments such as detection agencies, it is necessary to convert the current in the line into a relatively uniform current. The use of transformers can play the role of current conversion and electrical isolation, and improve the safety of the power supply system.

In one embodiment, the three-phase load balance adjustment device further includes: a warning bell, the warning bell is connected to the detection mechanism, and the warning bell is configured so that when the current in the three-phase line is greater than a preset threshold , the bell will sound as a warning.

When the current detected in the detection mechanism is greater than the preset threshold, the warning bell can give a warning to remind the manager of the station to adjust the heavy load phase, cut off the heavy load phase, and connect the light load phase. The warning bell can promptly remind the manager of the station area that there is a problem with the current in the three-phase line, and adjust the three-phase load in time, which can ensure the safety of users' electricity use and the safety of the power supply system.

In one embodiment, the three-phase load balance adjustment device further includes: a casing, the detection mechanism, the three-phase line and the three-phase switch are installed in the casing, and the casing is configured to protect the The detection mechanism, the three-phase line and the three-phase switch.

The detection mechanism, the three-phase line and the three-phase switch are installed in the casing, and the casing can be fixed on the wall. The three-phase button in the above embodiment can be installed on the casing, and the station manager can directly adjust the disconnection and connection of one of the three phases through the three-phase button installed on the casing. The shell can play the role of dustproof and moistureproof, and protect the three-phase line.

In an embodiment, the three-phase load balance adjustment device further includes: a fixing mechanism, the fixing mechanism is installed on the housing, and the fixing mechanism is configured to fix the housing on the wall.

The fixing mechanism can fix the three-phase load balance adjustment device on the wall, which is convenient for the station manager to observe and operate.

The three-phase load balance adjustment device provided by the embodiment of the utility model plays the role of adjusting the three-phase load by setting a detection mechanism, a three-phase switch and a three-phase line, and installing it on the front end of the electric energy meter of the user. The three-phase load balance adjustment device is installed at the front end of the user's electric energy meter, and the three-phase load can be directly adjusted for each household. Each adjustment device can easily adjust and switch between the three-phase loads for the electric energy meter it controls, and switch the load of the phase with the heavier load to the phase with the lighter load, so that the three-phase load can be balanced. Observe the balance of the three-phase load current of the electric energy meter controlled by each three-phase load balance adjustment device through the detection mechanism. When the three-phase load current is unbalanced, adjust the on-off situation of the three-phase line according to the actual load, so as to directly Adjust the three-phase load. The three-phase load balance adjustment device has the advantages of simple structure, flexible use, low cost and high reliability, and can timely deal with the three-phase imbalance caused by the unbalanced load growth, reduce the line loss rate, and effectively improve the voltage quality.

Description of drawings

FIG. 1 is a schematic structural diagram of a three-phase load balance adjustment device provided by an exemplary embodiment of the present application.

Fig. 2 is a schematic diagram of the wiring principle of a three-phase load balance adjustment device provided by an exemplary embodiment of the present application.

Fig. 3 is a left view structural diagram of a three-phase load balance adjustment device provided by an exemplary embodiment of the present application.

FIG. 4 is a schematic diagram of a rear view structure of a three-phase load balance adjustment device provided by an exemplary embodiment of the present application.

FIG. 5 is a schematic bottom view of a three-phase load balance adjustment device provided by an exemplary embodiment of the present application.

Description of reference signs: 1. Three-phase load balance adjustment device; 11. Three-phase switch; 12. Three-phase line; 13. Three-phase button; 14. Detection mechanism; 15. Three-phase indicator light; 16. Shell; 17. L-shaped buckle; 18, groove.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. example. Based on the embodiments of the present utility model, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model.

In addition, in the exemplary embodiments, since the same reference numerals denote the same components with the same structure or the same steps of the same method, if one embodiment is exemplarily described, only the same elements as those already described will be described in other exemplary embodiments. Different structures or methods of the embodiments are described.

Throughout the specification and claims, when one element is described as being "connected" to another element, the one element may be "directly connected" to the other element, or "electrically connected" to the other element through a third element. In addition, unless explicitly described to the contrary, the term "comprising" and its corresponding terms should only be understood as including the stated components, and should not be understood as excluding any other components.

Application overview

With the continuous improvement of the national economy and the continuous upgrading of electrical equipment, the load structure of the low-voltage distribution network has changed. People's demand for electric energy and quality requirements are increasing day by day. Stable operation is of great significance, and the quality of power is also of great significance to the normal order of people's living standards. In my country's low-voltage distribution network, the problem of three-phase imbalance has existed for a long time. This problem is likely to cause misoperation of protection devices, affect the reliability of the power supply system, cause a decline in power quality, and pose a greater threat to the safety of users and the power supply system. .

In the process of power consumption in life and production, the unbalanced three-phase may cause asymmetry in the operation of the transformer, which in turn will increase the loss of the transformer. The power loss of distribution transformers includes no-load loss and load loss. When the three-phase load is unbalanced, the zero-sequence current generated by the transformer will flow in the oil tank wall, and heat will generate additional losses. In severe cases, the transformer may be burned.

Three-phase unbalance will also affect the loss of distribution lines. The power loss due to current flow through a conductor is proportional to the square of the line current. In the three-phase four-wire power supply line, its power loss is: P＝I _U ² R _U +I _V ² R _V +I _W ² _R W +I ₀ ² R ₀ , among them, I _U , I _V , I _W represents the current of each phase distribution line, I ₀ represents the neutral wire current, R _U , R _V , R _W represent the resistance value of each phase distribution line, and R ₀ represents the neutral wire resistance value. When the three-phase load is balanced, I _U ＝I _V ＝I _W ＝I, I ₀ ＝0, the loss is P=3I ² R, where I represents the current passing through the distribution line, and R represents the resistance value of the distribution line . At the maximum unbalance, that is, one phase is 3I, the other two phases are zero, the neutral line current is 3I, and the power loss is (3I) ² R+(3I) ² R ₀ , so under the condition of delivering the same capacity, the three The line loss caused by phase load asymmetry is relatively large, and the economic benefit is extremely low during operation.

The three-phase unbalance will also affect the user side. The unbalanced three-phase load may cause one or two of the phases to be overloaded, resulting in increased line loss and a decline in power quality to a certain extent. adverse effects of electricity. The burning of the transformer leads to partial or overall power failure of the power supply system, which will also cause certain economic losses. Moreover, the eddy current loss makes the operating temperature of the transformer continue to rise, which brings certain safety hazards to people and equipment.

Three-phase unbalance will also affect the safe operation of electrical equipment. When the three-phase is unbalanced, the three-phase current values are different, and at this time, the neutral line will have a current passing through, resulting in an impedance drop, causing the drift of the neutral point and the three-phase unbalance, and in severe cases, it will cause the voltage on the higher voltage side The user's electrical equipment burns out, and the user's electrical equipment on the lower voltage side cannot be used normally, which has a serious impact on the safe and stable operation of the electrical equipment. Moreover, since the unbalanced voltage has three voltage components: positive sequence, negative sequence, and zero sequence, when this unbalanced voltage is input to a motor powered by 380V, the negative sequence voltage generates a rotating magnetic field that is opposite to the rotating magnetic field generated by the positive sequence voltage. , to play a braking role, which will inevitably cause the output power of the motor to decrease, resulting in a decrease in the efficiency of the motor. At the same time, the temperature rise and reactive power loss of the motor will also increase with the unbalance of the three-phase voltage, and the operation of the motor under the unbalanced three-phase condition will bring huge economic losses and potential safety hazards.

The reason for the three-phase imbalance may be that there are a large number of single-phase loads, asymmetrical loads, and nonlinear loads on the user side of the distribution transformer. Cause unbalanced three-phase load distribution. Or when individual users add large-load electrical equipment to their homes, it may cause serious deviations in the three-phase load. Therefore, in order to solve the problem of three-phase unbalance and improve the safety of the power supply system, it is necessary to adjust the three-phase unbalance to reduce the unbalance of the three-phase load current and improve the quality of power supply.

Exemplary device

Fig. 1 is a schematic structural diagram of a three-phase load balance adjustment device provided by an exemplary embodiment of the present application, and Fig. 2 is a schematic diagram of the wiring principle of the three-phase load balance adjustment device provided by an exemplary embodiment of the present application, as As shown in Figures 1 and 2, an embodiment of the present invention provides a three-phase load balance adjustment device 1, comprising: a three-phase switch 11, the three-phase switch 11 is connected to a detection mechanism 14, and the three-phase switch 11 is configured according to The balance of the three-phase load current in the line controls the closure or disconnection of each phase line respectively; the three-phase line 12, each phase in the three-phase line 12 is connected to each switch in the three-phase switch 11 respectively, and the three-phase line The phase line 12 is configured to carry out single-phase power supply according to the opening and closing of the three-phase switch 11; and the detection mechanism 14, the detection mechanism 14 is connected with the three-phase line 12, and the detection mechanism 14 is configured to detect the current situation in the three-phase line 12; wherein , the detection mechanism 14, the three-phase line 12 and the three-phase switch 11 are all installed at the front end of the user electric energy meter.

The detection mechanism 14 is used to detect the current condition of one phase of the three-phase line 12 energized, and the detection of the detection mechanism 14 can obtain the power supply phase difference and the corresponding current magnitude. The connection and disconnection of the three-phase line 12 is controlled by the three-phase switch 11, and the connection and disconnection of the three-phase line 12 can be controlled according to the balance of the three-phase load detected by the front-end equipment, thereby adjusting the three-phase load. load. The three phases can include phase A, phase B and phase C. For example, the load of phase A is heavy and the load of phase C is light. You can find the load supplied by the power supply of phase A, disconnect the power supply of phase A load, and then close the load of phase C. The switch is connected to the C-phase line, and the power flows from the C-phase line of the three-phase load balance adjustment device 1 to the user's electric energy meter, and then enters the user's home for power supply. At the same time, only one phase switch or one phase line is closed to prevent short circuit. The three-phase switches 11 are respectively connected in series with the three-phase lines 12, and the three-phase lines 12 are connected in parallel.

As shown in Figure 1, there are multiple branches in the outgoing line of the distribution transformer, and each branch includes phases A, B, C, and N on the low-voltage side. Among them, the three phases A, B, and C are the above-mentioned three phases, and 10Kv enters Distribution transformers are installed on the line, KM represents the AC contactor, KM1, KM2, KM3 represent the A-phase AC contactor, B-phase AC contactor and C-phase AC contactor respectively, FU represents the fuse, FU1 and FU2 represent the first-phase AC contactor respectively. One fuse and the second fuse, SA stands for three-phase switch, SA1, SA2, SA3 stands for A-phase switch, B-phase switch and C-phase switch respectively, CT stands for transformer, TA stands for ammeter, each branch stands for a user .

The three-phase load balance adjustment device 1 is connected in series to the front end of the electric energy meter of the user, and is installed on the circuit between the secondary protection box and the electric energy meter of the user, which is different from the installation of the device for adjusting the three-phase load on the transformer in the prior art. Location. The power supply can be adjusted by the three-phase load balance adjustment device 1, and then flow into the user's electric energy meter, which can be adjusted for each household, and the use is more flexible and the adjustment effect is more significant. For example, if there are six households in a building, and there are six electric energy meters in total, a three-phase load balance adjustment device 1 is installed on the front ends of the six electric energy meters, and the power supply flows into the electric energy of the users through the three-phase load balance adjustment device 1. The three-phase load is balanced and adjusted before it flows into the user's electric energy meter.

The three-phase load balance adjustment device 1 provided by the embodiment of the utility model is provided with a detection mechanism 14, a three-phase switch 11 and a three-phase line 12, and installed on the front end of the electric energy meter of the user to adjust the three-phase load. The three-phase load balance adjustment device 1 is installed at the front end of the electric energy meter of the user, and the three-phase load can be directly adjusted for each household. Each adjustment device can easily adjust and switch between the three-phase loads for the electric energy meter it controls, and switch the load of the phase with the heavier load to the phase with the lighter load, so that the three-phase load can be balanced. The current condition of each three-phase load balance adjustment device 1 is observed through the detection mechanism 14. When the three-phase load current is unbalanced, the on-off condition of the three-phase line 12 is adjusted according to the actual load, thereby directly adjusting the three-phase load. The three-phase load balance adjustment device 1 is simple in structure, flexible in use, low in cost and high in reliability, can promptly deal with three-phase imbalance caused by unbalanced load growth, reduces line loss rate, and effectively improves voltage quality.

In one embodiment, as shown in Figure 1 and Figure 2, the above-mentioned three-phase load balance adjustment device 1 may also include: a three-phase indicator light 15, the three-phase indicator light 15 is connected in parallel with the three-phase line 12, and the three-phase indicator light 15 It is configured to turn on the light when it is powered on, so as to display the single-phase lines that have been connected and supply power in the current three-phase lines 12 .

The three-phase indicator light 15 is used to display which current line of the phase is connected, which is convenient for the station area manager to perform the phase change operation. For example, when the load of phase A is heavy and the load of phase C is light, you can find the switch of the phase A line through the indicator light, disconnect the switch corresponding to the phase A line, the load is powered off, and then press the switch of phase C to connect C The phase line is powered by the C-phase line, and the power supply is supplied from the secondary protection through the main circuit breaker of the three-phase load balance adjustment device 1, then to the C-phase AC contactor, the user's electric energy meter, and finally enters the user's home for power supply. Through the three-phase indicator light 15, the on-off status of the three-phase line 12 in the three-phase load balance adjustment device 1 can be quickly known, which helps the manager of the station area to quickly perform three-phase load balance adjustment.

In an embodiment, the above-mentioned three-phase load balance adjustment device may further include: a protector connected in series with the three-phase line, and the protector is configured to disconnect the main line to protect Three-phase line; where the residual current represents the current generated when the vector sum of the phase currents passing through the protector is not zero.

Protectors can include residual current action protectors, which are also known as leakage protectors, which are mainly used to provide protection against dangerous and potentially fatal electric shocks, and also for long-term continuous ground fault currents that cannot be operated by overcurrent protection appliances Provide protection against the resulting fire hazard. Installing residual current operating protectors in low-voltage power grids is an effective protective measure to prevent personal electric shocks, electrical fires, and electrical equipment damage. Among them, the residual current refers to the current in which the current vector sum of each phase (including the neutral line) in the low-voltage distribution line is not zero. When an accident occurs on the power consumption side, the current flows from the electrified body through the human body to the earth, so that the magnitude of the current I phase and I in the incoming and outgoing lines of the main circuit is not equal. At this time, the instantaneous vector composite effective value of the current is called residual current. Commonly known as leakage. The instantaneous current of the residual current flowing through the main circuit of the residual current action protector is the effective value of the current. Therefore, due to the change of the residual current, it indicates that the insulation of the live conductor to the ground is damaged, and the detection of the residual current link is used to start the tripping of the protection device, thereby coming To prevent fire caused by electric shock and ground arc.

In one embodiment, as shown in FIG. 2 , the above-mentioned three-phase load balance adjustment device 1 may further include: three-phase buttons 13, and each button in the three-phase buttons 13 corresponds to each switch in the three-phase switches 11 respectively. To connect, the three-phase button 13 is configured to control the closing or opening of the three-phase switch 11; wherein, the three-phase button 13 is controlled by the station manager.

The three-phase button 13 controls the three-phase switch 11 correspondingly, and the three-phase button 13 can be manipulated by the station manager, who directly controls the closing or opening of the three-phase switch 11 through the three-phase button 13 . That is to say, the three-phase load balance adjustment device 1 is installed on the user side. When the three-phase imbalance occurs on the user side, it can be directly handled on site, and the phase with a lighter load can be switched for power supply. If there is a large load deviation in the phase, it can be switched on site in time.

In an embodiment, the three-phase switch may include: an AC contactor configured to be closed or disconnected according to an instruction of the three-phase button to connect the single-phase line.

The AC contactor is an intermediate control element, and its advantage is that it can frequently turn on and off the line, and control a large current with a small current. Working with the thermal relay can also play a certain role in overload protection for the load equipment. The AC contactors are KM1, KM2 and KM3 in Figure 1, respectively. Because the AC contactor is turned on and off by electromagnetic field suction, it is more efficient and flexible than manual opening and closing circuits. It can open and close multiple load lines at the same time, and it also has a self-locking function. After manually short-circuiting and closing, it can enter the self-locking state and continue to work. AC contactors are widely used as power breaking and control circuits.

Through the contact locking of the AC contactor, it can ensure that only one phase of the AC contactor is closed, thereby preventing the occurrence of a short circuit. Compared with the power electronic equipment, the mechanical equipment has stronger anti-interference ability and lower malfunction rate. Reliable power supply is ensured while the load is adjusted.

In an embodiment, the above-mentioned three-phase load balance adjustment device may further include: a switching mechanism, which is respectively connected to each phase switch in the three-phase switches, and the switching mechanism is configured to , to switch any switch in the three-phase switch to the closed state or the open state.

The switching mechanism may include a processor and a controller. The processor is connected to the controller. The processor is used to receive the power supply phase difference and the corresponding current magnitude detected by the detection mechanism, and judge whether the current line is present according to the pre-detection three-phase load device. The unbalanced condition of the three-phase load current. For example, it is currently detected that the load of phase A is heavy and the load of phase C is relatively light. After the processor obtains the result that the line of phase A needs to be cut off and the line of phase C is connected, it will be transmitted to the controller, and the controller will control the disconnection and switching of the three-phase switch. Close, turn off the A-phase switch, close the C-phase switch, connect the C-phase line, the power will flow from the C-phase line of the three-phase load balance adjustment device to the user's electric energy meter, and then enter the user's home for power supply.

The switching mechanism can play the role of automatic switching, and can also play a certain role in regulating the three-phase load without human intervention. The switching mechanism can also have a built-in communication module to transmit the three-phase load conditions of each household to the master control platform, and the master control platform can perform remote adjustment according to the three-phase load conditions and remotely control the three-phase switches.

In one embodiment, the detection mechanism may include: a transformer, which is connected to the three-phase line, and the transformer is configured to reduce the current ratio in the three-phase line to detect the current situation in the three-phase line; The three-phase line is connected, and the ammeter is constructed to detect the current condition in the three-phase line.

The transformer is the CT in Figure 1, and the transformer can include a current transformer, which can convert a large current into a small current for measurement or protection systems. The function of the transformer is mainly to convert the large current into a standard small current (5A or 1A, both refer to the rated value) in proportion to realize the standardization and miniaturization of the detection mechanism, protector, and automatic control equipment (switching mechanism). At the same time, the transformer can also be used to isolate the high-voltage system to ensure the safety of people and equipment. In the power supply line, the current difference is from a few amps to tens of thousands of amps. The current in the line is relatively high, and it is very dangerous to measure it directly. In order to facilitate the measurement of secondary instruments such as detection agencies, it is necessary to convert the current in the line into a relatively uniform current. The use of transformers can play the role of current conversion and electrical isolation, and improve the safety of the power supply system. The ammeter is TA in Figure 1, and the ammeter includes an A-phase ammeter, a B-phase ammeter, and a C-phase ammeter, which detect the current passing through each phase respectively.

In an embodiment, the above-mentioned three-phase load balance adjustment device may further include: a warning bell connected to the detection mechanism, and the warning bell is configured to ring to warn when the current in the three-phase line is greater than a preset threshold .

When the current detected in the detection mechanism is greater than the preset threshold, the warning bell can give a warning to remind the manager of the station to adjust the heavy load phase, cut off the heavy load phase, and connect the light load phase. The warning bell can promptly remind the manager of the station area that there is a problem with the current in the three-phase line, and adjust the three-phase load in time, which can ensure the safety of users' electricity use and the safety of the power supply system.

In one embodiment, the above-mentioned three-phase load balance adjustment device further includes: a casing, in which the detection mechanism, three-phase line and three-phase switch are installed, and the casing is configured to protect the detection mechanism, three-phase line and three-phase switch.

The detection mechanism, the three-phase line and the three-phase switch are installed in the casing, and the casing can be fixed on the wall. The three-phase button in the above embodiment can be installed on the casing, and the station manager can directly adjust the disconnection and connection of one of the three phases through the three-phase button installed on the casing. The shell can play the role of dustproof and moistureproof, and protect the three-phase line.

The three-phase current detected by the detection mechanism can be displayed on the casing through the ammeter, so that the station manager can directly observe the three-phase current.

In an embodiment, the above-mentioned three-phase load balance adjustment device may further include: a fixing mechanism, which is installed on the casing, and the fixing mechanism is configured to fix the casing on the wall.

A fixing mechanism can be arranged on the casing, and the fixing mechanism can include expansion screws, which are nailed into the wall to fix the three-phase load balance adjustment device. Fig. 3 is a left view structural diagram of a three-phase load balance adjustment device provided by an exemplary embodiment of the present application. As shown in Fig. 3, the fixing mechanism can also include an L-shaped buckle 17, and a hook or a hook is set on the wall. The cross bar is used to hang the three-phase load balance adjustment device 1 on the hook or the cross bar on the wall through the L-shaped buckle 17, which is convenient for disassembly and maintenance of the three-phase load balance adjustment device 1 . Figure 4 is a schematic diagram of the rear structure of a three-phase load balance adjustment device provided by an exemplary embodiment of the application, and Figure 5 is a schematic bottom view of the three-phase load balance adjustment device provided by an exemplary embodiment of the application , as shown in Figure 4 and Figure 5, the fixing mechanism can also include a groove 18, and a clamping strip matched with the groove 18 is provided on the wall, and the groove 18 can slide on the clamping strip to fix and remove the three-phase load The balance adjustment device 1 cooperates with the clip through the groove 18, which facilitates disassembly and maintenance of the three-phase load balance adjustment device 1 .

The above descriptions are only preferred embodiments of the present utility model, and are not intended to limit the present utility model. Any modifications, equivalent replacements, etc. made within the spirit and principles of the present utility model shall be included in the present utility model. within the scope of the new protection.

Claims (10)

1. A three-phase load balance adjustment device, characterized in that, comprising: a three-phase switch, the three-phase switch is configured to separately control the closing or opening of each phase line according to the balance of the three-phase load current in the three-phase line; A three-phase line, each phase of the three-phase line is respectively connected to each switch of the three-phase switch, and the three-phase line is configured to perform single-phase power supply according to the opening and closing of the three-phase switch ;as well as A detection mechanism, the detection mechanism is connected to the three-phase line, and the detection mechanism is configured to detect the current condition in the three-phase line; Wherein, the detection mechanism, the three-phase line and the three-phase switch are all installed at the front end of the electric energy meter of the user. 2. The three-phase load balance adjustment device according to claim 1, further comprising: A three-phase indicator light, the three-phase indicator light is connected in parallel with the three-phase line, and the three-phase indicator light is configured to turn on the light when it is powered on, so as to display the single-phase line that has been connected and is currently supplying power among the three-phase lines. 3. The three-phase load balance adjusting device according to claim 1, further comprising: A protector, the protector is connected in series with the three-phase line, and the protector is configured to disconnect the main line to protect the three-phase line when the current value of the residual current is greater than a preset current value; wherein, the remaining The current represents the current generated when the vector sum of the currents of each phase passing through the protector is not zero. 4. The three-phase load balance adjusting device according to claim 1, further comprising: Three-phase buttons, each of the three-phase buttons is correspondingly connected to each of the three-phase switches, and the three-phase buttons are configured to control the closing or opening of the three-phase switches; wherein, The three-phase button is controlled by the station manager. 5. The three-phase load balance adjustment device according to claim 4, wherein the three-phase switch comprises: An AC contactor, the AC contactor is configured to be closed or disconnected according to the indication of the three-phase button to connect the single-phase line. 6. The three-phase load balance adjusting device according to claim 1, further comprising: A switching mechanism, the switching mechanism is respectively connected to each phase switch in the three-phase switches, and the switching mechanism is configured to switch any one of the three-phase switches according to the balance of the three-phase load current in the bus line to the closed state or the open state. 7. The three-phase load balance adjustment device according to claim 1, wherein the detection mechanism comprises: a transformer, the transformer is connected to the three-phase line, and the transformer is configured to reduce the current ratio in the three-phase line to detect the current condition in the three-phase line; an ammeter, the ammeters are respectively connected to the three-phase lines, and the ammeters are configured to detect current conditions in the three-phase lines. 8. The three-phase load balance adjustment device according to claim 1, further comprising: An alarm bell, the alarm bell is connected to the detection mechanism, and the alarm bell is configured to ring to warn when the current in the three-phase line is greater than a preset threshold. 9. The three-phase load balance adjusting device according to claim 1, further comprising: The casing, the detection mechanism, the three-phase line and the three-phase switch are installed in the casing, and the casing is configured to protect the detection mechanism, the three-phase line and the three-phase switch. 10. The three-phase load balance adjusting device according to claim 9, further comprising: A fixing mechanism, the fixing mechanism is installed on the casing, and the fixing mechanism is configured to fix the casing on the wall.

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