WO2020083396A1

WO2020083396A1 - Commutation type automatic adjusting device for three-phase current imbalance

Info

Publication number: WO2020083396A1
Application number: PCT/CN2019/113437
Authority: WO
Inventors: 张孝云; 张洪波; 刘鼎立; 单冠华; 李建; 刘宗振
Original assignee: 山东电工电气集团新能科技有限公司; 山东电工电气集团有限公司
Priority date: 2018-10-25
Filing date: 2019-10-25
Publication date: 2020-04-30
Also published as: CN209016718U; KR20200125997A; KR102484100B1

Abstract

A commutation type automatic adjusting device for three-phase current imbalance, comprising: a main controller, a commutator, a first current transformer and an anti-power-off electrical appliance element combination. The first current transformer is configured to measure a bus current on the outgoing side of a distribution transformer and send a measured current signal to the main controller; the main controller is configured to collect and calculate a three-phase line current in the bus current on the outgoing side of the distribution transformer, calculate three-phase current imbalance according to the three-phase line current, generate a commutation strategy by means of a commutation algorithm on the basis of the three-phase current imbalance, and send a commutation command corresponding to the commutation strategy to a target commutator; and the commutator is electrically connected to a three-phase branch line and a user load by means of the anti-power-off electrical appliance element combination, is configured to receive a query command and/or a commutation command from the main controller, send a phase sequence in which a load is currently located and a load current to the main controller, and/or perform a commutation action on the basis of the commutation command.

Description

Commutation type three-phase current unbalance automatic adjustment device

Cross-reference of related applications

This application is based on a Chinese patent application with an application number of 201821741462.9 and an application date of October 25, 2018, and claims the priority of the Chinese patent application. The entire contents of the Chinese patent application are hereby incorporated into this application by way of introduction.

Technical field

This application relates to the field of governance of three-phase current imbalance in distribution networks, in particular to a commutation type three-phase current imbalance automatic adjustment device.

Background technique

The low-voltage distribution network is an important part of the final power supply network, which directly provides electricity to various users. The low-voltage distribution network usually adopts a three-phase four-wire power supply mode, and single-phase power consumption and three-phase power consumption coexist. The characteristics of single-phase power consumption are complex, such as large differences in user habits, strong randomness of power consumption, low simultaneous rate of power consumption, and large dispersion of space-time distribution. The above characteristics of single-phase power consumption cause the three-phase current unbalance phenomenon to exist for a long time in the low-voltage distribution network. The harm caused by the three-phase current imbalance to the safe and economic operation of the low-voltage distribution network includes: putting the transformer in an unbalanced operation state, resulting in increased transformer losses, and the risk of long-term overload operation in the heavy-load phase; increased loss of low-voltage lines, Seriously affect the economic operation of low-voltage distribution networks; lead to unbalanced voltage and voltage deviation of each load node. When the load imbalance is serious and the debt ratio is high, the voltage of the back-end users of the line may be low, which directly affects the normal production and living power consumption of users; load nodes When the voltage imbalance is high, the negative sequence voltage component contained is seriously exceeded, which can cause a significant reduction in motor output power and motor efficiency.

The use of automatic commutation technology to distribute the load capacity undertaken by each phase by changing the phase sequence of the load access is the most direct and fundamental method to solve the problem of three-phase current imbalance. At present, some areas have begun to pilot three-phase current imbalance treatment devices based on automatic commutation technology, but many problems have also been exposed in actual operation. For example, during on-site installation and debugging, the debugger needs to pass the rod to operate; the device After being put into operation, the operating status and control effect of the device cannot be known without opening the box, and the degree of intelligence is low; the communication between the main controller and the commutator is unreliable, the success rate of the commutation is low, and the control effect is not obvious; If the switching time is too long, the user will be powered off for a few seconds or a few minutes; the commutation is unreliable, and short-circuits between phases occur frequently; when the commutator fails, there is no guarantee that the user's power supply will not be interrupted.

Summary of the invention

The embodiments of the present application are expected to provide a commutation type three-phase current imbalance automatic adjustment device, which can avoid arcing generated at the moment of load cutoff, avoid inrush current generated at the moment of load input, and avoid interphase short-circuit caused by unreliable switching of magnetic holding relay .

The technical solutions adopted in the embodiments of the present application are:

An embodiment of the present application provides a commutation type three-phase current imbalance automatic adjustment device, including: a main controller, a commutator, a first current transformer provided on the busbar on the outlet side of the distribution transformer, and a power-off prevention appliance Element combination; wherein, the main controller is electrically connected to the bus-bar on the outlet side of the distribution transformer; the main controller communicates with the phase converter in a power carrier or wireless manner;

The first current transformer is configured to measure the bus current on the outlet side of the distribution transformer and send the measured current signal to the main controller;

The main controller is configured to collect and calculate the three-phase line current in the bus current on the outlet side of the distribution transformer, calculate the three-phase current unbalance based on the three-phase line current, and based on the three-phase current The unbalance degree generates a commutation strategy through a commutation algorithm, and sends a commutation command corresponding to the commutation strategy to the target commutator;

The commutator is electrically connected to the three-phase branch downline and the user load through the combination of the anti-breakout electrical component, and is configured to receive the query command and / or the commutation command sent by the main controller to the The main controller sends the current phase sequence and load current of the load, and / or performs a commutation action based on the commutation command;

The anti-breakout electrical component combination includes a three-phase circuit breaker, an auxiliary contact switch, and an AC contactor; the input end of the three-phase circuit breaker is respectively connected to the three-phase line of the busbar on the outlet side of the distribution transformer. The outlet ends of the three-phase circuit breakers are respectively connected to the corresponding three-phase inlets of the inverter; the inlet end of the auxiliary contact switch is connected to one phase of the three-phase circuit, and the outlet of the auxiliary contact switch Is connected to the incoming end of the AC contactor coil; the outgoing end of the AC contactor coil is connected to the neutral line, and the incoming end of the AC contactor is connected to one phase of the three-phase line, The contact outlet end of the AC contactor is connected to the load.

In an optional embodiment of the present application, the device further includes a terminal application (APP), and the terminal application performs data communication with the main controller through wireless communication.

In an optional embodiment of the present application, the inverter includes: a first microcontroller and a first power carrier and wireless communication module connected thereto, four first voltage transformers, and a load current transformer Device, magnetic holding relay and its driving circuit;

The first power carrier and the wireless communication module are configured to communicate with the main controller through a power carrier or wireless data transmission mode;

The four first voltage transformers are configured to convert three-phase line voltage and load voltage into three-phase line voltage signal analog and load voltage signal analog respectively and send to the first microcontroller;

The load current transformer is configured to collect load current and convert it into a load current analog quantity, and send the load current analog quantity to the first microcontroller;

The magnetic holding relay and its driving circuit are configured to receive a commutation command of the first microcontroller and perform a commutation action based on the commutation command;

The first microcontroller is configured to compare the analog quantity of the load voltage signal with the analog quantity of the three-phase line voltage signal to identify the current phase sequence of the load; obtain the load current according to the analog signal of the load current; and also be configured to pass The power carrier and wireless communication module receive the query command and / or the commutation command sent by the main controller, and report the current state information of the commutator according to the requirements or to the commutation command according to the commutation command sent by the main controller The magnetic holding relay issues the commutation command.

In an optional embodiment of the present application, the phase converter further includes: a rotary switch, a dip switch, and a status indicator; wherein,

The rotary switch is configured to adjust the target phase sequence of the commutator based on the user's operation;

The dial switch is configured to set the address code of the commutator based on the user's operation;

The first microcontroller is further configured to determine the address code of the commutator according to the status bit of the dial switch; and also configured to determine the target of the commutator according to the position of the rotary switch Phase sequence, issuing a commutation switching command to the magnetic holding relay based on the target phase sequence;

The status indicator is configured to indicate the operating state, fault state, and current phase sequence of the commutator.

In an optional embodiment of the present application, the main controller includes: a second microcontroller and a second power carrier and wireless communication module connected thereto, three second voltage transformers and three second currents Transformer; where,

The second power carrier and the wireless communication module are configured to communicate with the phase converter through a power carrier or wireless data transmission mode;

The three second voltage transformers are configured to respectively convert the three-phase line voltage into a voltage signal analog quantity and send it to the second microcontroller;

The three second current transformers are configured to respectively convert the current signals passing through the three first current transformers into analog current signals, and send the analog current signals to the second microcontroller;

The second microcontroller is configured to determine the voltage value of the three-phase line according to the voltage signal analogs corresponding to the three second voltage transformers; to determine the current signal analogs corresponding to the three second current transformers The three-phase line current value determines the three-phase current unbalance degree according to the three-phase line current value.

In an optional embodiment of the present application, the main controller further includes: a wireless communication module, a memory, a key, and a display screen; wherein,

The wireless communication module is configured to perform data communication with the terminal application;

The memory is configured to record relevant data and time information generated during the operation of the main controller;

The button is configured to receive an input command; the input command is used for at least one of the following: status information query, parameter modification, and command issuance;

The display screen is configured to display status data of the main controller and the commutator;

The second microcontroller is also configured to receive the input command of the key; transmit the status data of the main controller and each inverter to be displayed to the display screen for display; and transmit the data to be recorded to the The memory is stored; also configured to perform data communication with the terminal application through the wireless communication module.

In an alternative embodiment of the present application, the magnetic holding relay and its driving circuit are provided with three magnetic holding relays with output terminals of the switching state feedback signal; the first microcontroller is configured as a magnetic holding relay After executing the switching or switching command, check whether the magnetic holding relay performs the switching or switching command through the switching state feedback signal output terminal of the magnetic holding relay; when the magnetic holding relay performs the switching or switching operation is not in place , Then no longer send or switch commands to other magnetic holding relays.

In an optional embodiment of the present application, the first microcontroller is further configured to send the status information of the inverter to the main controller, and the status information includes at least one of the following: an address code, The phase sequence, load current, and fault status.

In an optional embodiment of the present application, the main controller and the inverter are provided with power modules; the power modules are configured to convert AC power to specific DC power and specific DC power It is used to supply power to the main controller or the inverter.

The embodiment of the present application can avoid the arcing generated at the moment of load removal, the inrush current generated at the moment of load input, and the phase-to-phase short circuit caused by the unreliable switching of the magnetic holding relay. Technically ensure that the commutation time is controlled within 10 milliseconds (ms) to ensure that the commutator can be removed from the circuit in a timely manner when the short-circuit fault occurs due to some unexpected reason, and the user load is connected at the same moment. Continue to supply power on one phase. In addition, through the use of a matching developed terminal application (APP), the device can be debugged on site without going on the pole, saving time and effort. After the device is put into operation, voltage data, current data, three-phase current unbalance, phase sequence of each inverter, load current, fault status and other information can be viewed on the terminal application (APP).

The advantages and positive effects of the embodiments of the present application include:

1. Adopt relay current zero-crossing and voltage zero-crossing input technology to ensure no arcing at the moment of cutting and no inrush current at the moment of input, extend the service life of the relay and improve the reliability of the relay operation;

2. Adopt the magnetic holding relay with the output terminal of the switching state feedback signal to avoid the phase-to-phase short circuit problem caused by the magnetic holding relay failing to perform the switching operation;

3. The commutation is rapid, and the commutation action can be completed within 10 milliseconds (ms), which will not affect the normal operation of the electrical equipment;

4. When the commutator has a short-circuit fault due to some unexpected reason, the combination of anti-power-off electrical components can remove the commutator from the circuit within the first time and ensure that the user's power supply is not interrupted;

5. Use terminal application to manage the device, easy to operate, small operation and maintenance workload, high efficiency.

BRIEF DESCRIPTION

FIG. 1 is a usage state diagram of a commutation type three-phase current unbalance automatic adjustment device according to an embodiment of the present application;

2 is a block diagram of the functional circuit composition of the main controller of the commutation type three-phase current unbalance automatic adjustment device according to an embodiment of the present application;

3 is a block diagram of a functional circuit of a commutator of a commutated three-phase current imbalance automatic adjustment device according to an embodiment of the present application;

4 is a schematic diagram of the component combinations of the anti-breakout electrical components of the commutation type three-phase current imbalance automatic adjustment device according to an embodiment of the present application;

FIG. 5 is a schematic diagram of a display interface of a terminal application (APP) of an application embodiment.

detailed description

In order to further understand the content, features, and effects of the embodiments of the present application, the following embodiments are listed below, together with the drawings, which are described in detail below.

An embodiment of the present application provides a commutation-type three-phase current imbalance automatic adjustment device, as shown in FIG. 1, including: a main controller, a commutator, and a first current mutual inductance provided on the busbar on the outlet side of the distribution transformer A combination of an electric device and an anti-breakout electrical component; wherein, the main controller is electrically connected to the busbar on the outlet side of the distribution transformer; the main controller communicates with the inverter in a power carrier or wireless manner;

The main controller is a control terminal of a set of devices, which is electrically connected to the busbar on the outlet side of the distribution transformer; it is configured to collect and calculate the three-phase line current in the busbar current on the outlet side of the distribution transformer, according to Calculating the three-phase current unbalance degree of the three-phase line current, generating a commutation strategy based on the three-phase current unbalance degree through a commutation algorithm, and sending a commutation command corresponding to the commutation strategy to a target commutator;

The phase converter is an execution terminal of a set of devices, and is electrically connected with the three-phase branch downline and the user load through the combination of the anti-breakout electrical components, and is configured to receive the query command and the command sent by the main controller / Or a commutation command, sending the current phase sequence and load current of the load to the main controller, and / or performing a commutation action based on the commutation command;

In this embodiment, the master controller can be calculated based on the three-phase current imbalance _{(((average of} the I _maximum -I) / I _mean) × 100%), the calculated phase current imbalance.

In this embodiment, when a phase-to-phase short-circuit occurs, the short-circuit current forces the three-phase circuit breaker to trip, the three-phase circuit breaker linkage auxiliary contact closes, the auxiliary contact has current flowing, the coil in the AC contactor is energized, and the generated magnetic field causes electric shock Closed, it can continue to supply power for users from a certain phase.

In an optional embodiment of the present application, the device further includes a terminal application (APP), and the terminal application performs data communication with the main controller through wireless communication. Wherein, as an embodiment, the wireless communication method may be at least one of the following: wireless fidelity (Wi-Fi), Bluetooth, near field communication (NFC, Near Field Communication), etc. Of course, the embodiments of the present application It is not limited to the communication method between the mobile phone application and the main controller.

In this embodiment, the terminal application can help maintenance and management personnel to debug the device conveniently, quickly, modify parameters, check the running status, update the program online, etc. It is the smart center of the device. As an example, the terminal application may include the following display interface:

1) Real-time monitoring interface: display three-phase voltage, three-phase current, three-phase current unbalance and number of inverters;

2) Inverter interface: record the specific switching operation and corresponding time generated by the inverter;

3) Event Sequence Recording (SOE) interface, showing the addresses, phase sequence, load current and fault code of all inverters;

4) Parameter setting interface: set the IP address and port number, provide modification of the current transformer (CT, Current Transformer) transformation ratio, the time interval for issuing the commutation command of the main controller, and the remote commutation operation of the target commutator , In addition, it also provides operation options such as connecting to the network, disconnecting the network and network timing.

In an optional embodiment of the present application, as shown in FIG. 2, the main controller includes: a second microcontroller and a second power carrier and wireless communication module connected thereto, and three second voltage transformers And three second current transformers; where,

The second microcontroller is configured to determine the three-phase line voltage value according to the three-phase voltage signal analog quantity corresponding to the three second voltage transformers; according to the current signal corresponding to the three second current transformers Quantity, determine the three-phase line current value, and determine the three-phase current unbalance degree according to the three-phase line current value.

In this embodiment, the second voltage transformer measures the three-phase voltage on the low-voltage outlet side of the transformer, and the first voltage transformer measures the three-phase voltage on the user side. After transmission through a certain length of transmission line, the value will be relatively low some. The first current transformer is used to measure large current, and the second current transformer is used to measure small current. The second current transformer on the main controller cannot be directly used to measure large current. The measurement of large current is done by the first current transformer, and then The second current transformer performs a second transformation on the current output signal of the first current transformer; the current signal output terminals of the three first current transformers are electrically connected to the three second current transformer input terminals on the main controller .

In an optional embodiment of the present application, the main controller further includes: a wireless communication module, a memory, a key, and a display screen; where, as an example, the wireless communication module may be implemented by a Wi-Fi module ; The memory may be FLASH memory; the display screen may be realized through a liquid crystal display screen;

The display screen has a main control switch status interface, all inverter status interfaces, parameter setting interfaces, command sequence interfaces; configured to display status data of the main controller and the inverter;

In this embodiment, the display screen may have a main control switch status interface, all inverter status interfaces, parameter setting interfaces, and a command sequence interface; the main control switch status interface displays three-phase phase voltage, three-phase phase current, and neutral Unbalance of current and three-phase current; all the inverter status interface displays the phase sequence, load current and error status of the inverter; the parameter setting interface includes CT ratio setting, maximum number of inverter settings, neutral current Display, short time interval setting, long time interval setting, manual operation of a certain commutator setting, calibration setting; the command sequence interface displays the commutation commands and corresponding time points issued by the main controller to each commutator.

In an optional embodiment of the present application, as shown in FIG. 3, the phase converter includes: a first microcontroller and a first power carrier and wireless communication module connected thereto, and four first voltage transformers , A load current transformer, magnetic holding relay and its driving circuit;

The first power carrier and the wireless communication module are configured to enable the first microcontroller to communicate with the main controller through a narrow-wave power carrier or wireless data transmission mode;

The four first voltage transformers are configured to convert the three-phase line voltage and the load voltage into three-phase line voltage signal analogs and load voltage signal analogs, respectively, and send them to the first microcontroller;

The first microcontroller is configured to compare the analog quantity of the load voltage signal with the analog quantity of the three-phase line voltage signal to identify the current phase sequence of the load; obtain the load current according to the analog signal of the load current; and also be configured to pass The power carrier and wireless communication module receive the query command and / or commutation command sent by the main controller, and report the current status information of the commutator according to requirements (such as address code, phase sequence, load current, and fault status) Or issue a command to the magnetic holding relay according to the commutation command sent by the main controller.

Among them, the magnetic holding relay and its driving circuit are provided with three magnetic holding relays with output terminals of the switching state feedback signal; the three magnetic holding relay input terminals are respectively connected to the three-phase input and output terminals of A, B and C, and three The output terminal of the magnetic holding relay is short-circuited with copper bars and then connected to the load terminal; the first microcontroller is configured to pass the switching state feedback signal of the magnetic holding relay after the magnetic holding relay executes the switching or switching command The output end checks whether the magnetic holding relay performs the cast or cut command in place; when the magnetic holding relay performs the cast or cut action is not in place, it will no longer send the cast or cut command to other magnetic holding relays, thereby avoiding The phase-to-phase short circuit problem caused by the failure or failure of the magnetic latching relay to switch or execute.

Wherein, the status indicator may be a light emitting diode (LED, Light, Diode) indicator.

In an alternative embodiment of the present application, as shown in FIG. 4, the combination of the anti-breakout electrical components includes a three-phase circuit breaker, an auxiliary contact switch, and an AC contactor; The wire ends are respectively connected to the three-phase line, and the outlet ends of the three-phase circuit breakers are respectively connected to the three-phase inlets of the inverter; the auxiliary contact switch is linked to the three-phase circuit breaker, and the auxiliary contacts The incoming end of the point switch is connected to A in the three-phase line, and the outgoing end of the auxiliary contact switch is connected to the incoming end of the AC contactor coil; the outgoing end of the AC contactor coil is connected to the three-phase line The neutral line connection of the AC contactor, the input end of the AC contactor contact is connected to A in the three-phase line, and the output end of the AC contactor contact is connected to the load.

In an alternative embodiment of the present application, as shown in FIG. 5, the terminal application (APP) is a client management terminal of a set of devices, which can communicate with the main controller through wireless communication (such as Wi-Fi) Carry out data communication.

In an optional embodiment of the present application, the main controller and the inverter are provided with power modules; the power modules are configured to convert AC power to specific DC power and specific DC power It is used to supply power to the main controller or the inverter. As an example, the power module is responsible for converting AC220V AC power to a suitable DC power and supplying power to various functional circuits on the main controller and the inverter.

The process of treating the three-phase current unbalance by the phase-change three-phase current unbalance automatic adjustment device of the embodiment of the present application may include:

① The main controller is powered on, establish a Wi-Fi connection with the terminal (terminal such as a mobile phone), and complete the initial configuration according to the setting parameters of the terminal application (APP);

② After the inverter is powered on, after completing the initial configuration, scan the status of the rotary switch and switch the load to the phase sequence indicated by the rotary switch (initial phase sequence);

③ The main controller collects the three-phase bus current data on the outlet side of the distribution transformer, and analyzes whether the three-phase current unbalance exceeds the preset threshold. If it exceeds, proceed to step ④; if not, repeat the step after a certain time interval ③ , Analyze again whether the three-phase current unbalance exceeds the preset threshold;

④ The main controller sends query commands to each inverter through power line carrier or wireless mode, instructing each inverter to report the phase sequence code and load current data to the main controller;

⑤ After receiving the phase sequence code and load current data from each inverter, the main controller generates a control strategy according to the preset algorithm according to the three-phase current imbalance and the load distribution of each inverter, and gives the required The target commutator performing commutation sends the commutation command;

⑥ After the commutator receives the commutation command from the main controller, it performs the corresponding commutation operation to complete the commutation;

⑦After a certain time, go to step ③.

In actual implementation, prepare a set of commutation type three-phase current imbalance automatic adjustment device discussed in this utility model, which may include: a main controller, a number of phase converters, three first current transformers, a number of The combination of power-off electrical components and terminals (including APP corresponding to the commutation type three-phase current unbalance automatic adjustment device), in addition, the necessary connecting cables and tools should also be prepared.

As shown in Figure 1, a set of this device is installed in a power supply station area, and the number of inverters can be comprehensively determined according to the capacity and three-phase load distribution of the distribution transformer in the station area. After the installation is complete, proceed as follows:

The first step is to use the rotary switch on the inverter to switch the initial phase of each inverter to the phase where the load was before the inverter was installed.

The second step is to use the terminal to search the Wi-Fi wireless signal sent by the device on the spot and make a wireless connection.

The third step, after establishing the Wi-Fi connection, open the APP, set the CT ratio, commutation control short time interval and long time interval on the parameter setting interface, and perform time synchronization.

The fourth step is to switch to the real-time monitoring interface and observe the treatment effect of the device on the three-phase current imbalance in the station area.

The above are only optional implementations of this application, but the scope of protection of this application is not limited to this, any person skilled in the art can easily think of changes or replacements within the technical scope disclosed by the present invention, All should be covered within the scope of protection of this application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

A commutation type three-phase current unbalance automatic adjustment device, including: a main controller, a phase converter, a first current transformer and a combination of anti-breakout electrical components arranged on the busbar of the outlet side of the distribution transformer; The main controller is electrically connected to the bus on the outlet side of the distribution transformer; the main controller communicates with the phase converter in a power carrier or wireless manner;

The first current transformer is configured to measure the bus current on the outlet side of the distribution transformer and send the measured current signal to the main controller;

The main controller is configured to collect and calculate the three-phase line current in the bus current on the outlet side of the distribution transformer, calculate the three-phase current unbalance based on the three-phase line current, and based on the three-phase current The unbalance degree generates a commutation strategy through a commutation algorithm, and sends a commutation command corresponding to the commutation strategy to the target commutator;

The commutator is electrically connected to the three-phase branch downline and the user load through the combination of the anti-breakout electrical component, and is configured to receive the query command and / or the commutation command sent by the main controller to the The main controller sends the current phase sequence and load current of the load, and / or performs a commutation action based on the commutation command;

The anti-breakout electrical component combination includes a three-phase circuit breaker, an auxiliary contact switch, and an AC contactor; the input end of the three-phase circuit breaker is respectively connected to the three-phase line of the busbar on the outlet side of the distribution transformer. The outlet ends of the three-phase circuit breakers are respectively connected to the corresponding three-phase inlets of the inverter; the inlet end of the auxiliary contact switch is connected to one phase of the three-phase circuit, and the outlet of the auxiliary contact switch Is connected to the incoming end of the AC contactor coil; the outgoing end of the AC contactor coil is connected to the neutral line, and the incoming end of the AC contactor is connected to one phase of the three-phase line, The contact outlet end of the AC contactor is connected to the load.
The commutation type three-phase current unbalance automatic adjustment device according to claim 1, the device further comprises a terminal application, and the terminal application performs data communication with the main controller through wireless communication.
The commutation type three-phase current unbalance automatic adjustment device according to claim 1, wherein the commutator includes: a first microcontroller and a first power carrier and wireless communication module connected thereto, four first Voltage transformer, a load current transformer, magnetic holding relay and its driving circuit; where,

The first power carrier and the wireless communication module are configured to communicate with the main controller through a power carrier or wireless data transmission mode;

The four first voltage transformers are configured to convert three-phase line voltage and load voltage into three-phase line voltage signal analog and load voltage signal analog respectively and send to the first microcontroller;

The load current transformer is configured to collect load current and convert it into a load current analog quantity, and send the load current analog quantity to the first microcontroller;

The magnetic holding relay and its driving circuit are configured to receive a commutation command of the first microcontroller and perform a commutation action based on the commutation command;

The first microcontroller is configured to compare the analog quantity of the load voltage signal with the analog quantity of the three-phase line voltage signal to identify the current phase sequence of the load; obtain the load current according to the analog signal of the load current; and also be configured to pass The power carrier and wireless communication module receive the query command and / or the commutation command sent by the main controller, and report the current state information of the commutator according to the requirements or to the commutation command according to the commutation command sent by the main controller The magnetic holding relay issues the commutation command.
The commutation type three-phase current imbalance automatic adjustment device according to claim 3, wherein the commutator further comprises: a rotary switch, a dip switch, and a status indicator; wherein,

The rotary switch is configured to adjust the target phase sequence of the commutator based on the user's operation;

The dial switch is configured to set the address code of the commutator based on the user's operation;

The first microcontroller is further configured to determine the address code of the commutator according to the status bit of the dial switch; and also configured to determine the target of the commutator according to the position of the rotary switch Phase sequence, issuing a commutation switching command to the magnetic holding relay based on the target phase sequence;

The status indicator is configured to indicate the operating state, fault state, and current phase sequence of the commutator.
The commutation type three-phase current imbalance automatic adjustment device according to claim 3, wherein the main controller includes: a second microcontroller and a second power carrier and wireless communication module connected thereto, three second Voltage transformer and three second current transformers; where,

The second power carrier and the wireless communication module are configured to communicate with the phase converter through a power carrier or wireless data transmission mode;

The three second voltage transformers are configured to respectively convert the three-phase line voltage into a voltage signal analog quantity and send it to the second microcontroller;

The three second current transformers are configured to respectively convert the current signals passing through the three first current transformers into analog current signals, and send the analog current signals to the second microcontroller;

The second microcontroller is configured to determine the voltage value of the three-phase line according to the voltage signal analogs corresponding to the three second voltage transformers; to determine the current signal analogs corresponding to the three second current transformers The three-phase line current value determines the three-phase current unbalance degree according to the three-phase line current value.
The commutation type three-phase current imbalance automatic adjustment device according to claim 5, wherein the main controller further comprises: a wireless communication module, a memory, a key, and a display screen; wherein,

The wireless communication module is configured to perform data communication with the terminal application;

The memory is configured to record relevant data and time information generated during the operation of the main controller;

The button is configured to receive an input command; the input command is used for at least one of the following: status information query, parameter modification, and command issuance;

The display screen is configured to display status data of the main controller and the commutator;

The second microcontroller is also configured to receive the input command of the key; transmit the status data of the main controller and each inverter to be displayed to the display screen for display; and transmit the data to be recorded to the The memory is stored; also configured to perform data communication with the terminal application through the wireless communication module.
The commutation type three-phase current imbalance automatic adjustment device according to claim 3, wherein the magnetic holding relay and its driving circuit are provided with three magnetic holding relays with output terminals for switching state feedback signals;

The first microcontroller is configured to, after the magnetic holding relay executes the switching or switching command, check whether the magnetic holding relay executes the switching or switching command through the switching state feedback signal output terminal of the magnetic holding relay; When the magnetic holding relay does not perform the switching or switching operation in place, it will no longer send a switching or switching command to other magnetic holding relays.
The commutation type three-phase current imbalance automatic adjustment device according to claim 3, wherein the first microcontroller is further configured to send the status information of the commutator to the main controller, the status information Including at least one of the following: address code, phase sequence, load current, fault status.
The commutation type three-phase current imbalance automatic adjustment device according to any one of claims 1 to 8, wherein the main controller and the commutator are each provided with a power supply module; the power supply module is configured as The AC power is converted into a specific DC power, and the specific DC power is used to power the main controller or the inverter.