CN112542844A

CN112542844A - District electric energy quality optimizing apparatus based on regional wireless communication

Info

Publication number: CN112542844A
Application number: CN202011510192.2A
Authority: CN
Inventors: 钟建; 张庸; 程寅; 张艺凡; 刘凯; 赖飞宇
Original assignee: State Grid Sichuan Electric Power Co Ltd
Current assignee: State Grid Sichuan Electric Power Co Ltd
Priority date: 2020-12-19
Filing date: 2020-12-19
Publication date: 2021-03-23

Abstract

The invention discloses a district power quality optimization device based on regional wireless communication. The multi-phase unbalanced current regulation method takes MUC in the SVG module as a master control core, the SVG unit and the phase change controller communicate through RS485, three-phase unbalanced current is uniformly and coordinately regulated, unbalanced rough regulation is carried out through the phase change switch, fine regulation and reactive compensation are carried out through the SVG, the advantages of the two regulation modes are taken into consideration, and the equipment cost is maximally reduced. Sampling 2.4GHz wireless communication between the phase change controller and the phase change switch device, uploading load data of the phase change switch device to the phase change controller, sending a command of needing to switch phases to the corresponding phase change switch device by the controller according to the unbalanced load condition, and carrying out load adjustment by the switch according to the received command. The problem of low-voltage power grid electric energy quality is solved, power supply reliability is improved, distribution network loss is reduced, operation maintenance personnel field inspection and load adjustment workload are reduced, and working efficiency is improved.

Description

District electric energy quality optimizing apparatus based on regional wireless communication

Technical Field

The invention belongs to the technical field of three-phase load unbalance adjustment, and particularly relates to a district power quality optimization device based on regional wireless communication.

Background

For a three-phase power supply system in a distribution network area, the three-phase current imbalance is measured by the three-phase current imbalance degree. The unbalance degree of the three-phase current, i.e. the unbalance degree of the three-phase current, is usually represented by a symbol β, and according to the calculation method in the overhead distribution line and equipment operating regulations (SD 292-1988), the calculation formula of the unbalance degree of the three-phase current is as follows:

in the formula: imax and Imin are the maximum and minimum values of the three-phase current, respectively, and the unit is A.

Three-phase load is unbalanced, so that the power supply efficiency of a line and a distribution transformer is reduced if the three-phase load is unbalanced, and serious consequences such as burning of a certain phase wire, burning of a switch, even single-phase burning of the distribution transformer and the like can be caused if the heavy-load phase is overloaded.

The three-phase load is seriously unbalanced, the neutral point potential can be deviated, and the line voltage drop and the power loss can be greatly increased. The single-phase user connected to the heavy load phase is easy to have the problems of low voltage, unlighted electric lamp, low efficiency of electric appliances, easy burning of small water pump and the like. Single-phase users connected to the light load phase are prone to have high voltage, which may cause insulation breakdown of the electrical appliance, shorten the service life of the electrical appliance or damage the electrical appliance. For power users, the phenomenon of motor overheating can be caused by unbalanced three-phase voltage.

Meanwhile, unbalanced voltage is generated due to unbalanced three-phase load, voltage deviation is increased, neutral line current is increased, and accordingly line loss is increased. If zero sequence current exists in the distribution transformer in operation, zero sequence magnetic flux is generated in an iron core of the distribution transformer. The zero sequence magnetic flux can only pass through the oil tank wall and the steel component as a channel (no zero sequence current is arranged on the high-voltage side), the magnetic permeability of the steel component is low, and when the zero sequence current passes through the steel component, magnetic hysteresis and eddy current loss are generated, so that the local temperature of the steel component to be distributed and transformed is increased and heated. The distribution transformer winding insulation is subject to accelerated degradation due to overheating, resulting in reduced device life.

According to the regulation of the operation and maintenance regulations of the power distribution network (Q/GDW1519-2014), the load unbalance degree of the power distribution transformer is in accordance with the following conditions: the load unbalance degree of the Yyn0 wiring transformer is not more than 15%, and the zero line current is not more than 25% of the rated current of the transformer; the unbalance degree of the load of the Dyn11 wiring transformer is not more than 25%, and the current of a zero line is not more than 40% of the rated current of the transformer.

Considering that the short-time three-phase load unbalance out-of-limit caused by accidental factors is excluded from the treatment range, according to the measurement result, the continuous out-of-limit time within 1 day exceeding 1 hour is determined as 1 out-of-limit day. The distribution area with the average load rate of more than 20 percent and accumulated more than 5 three-phase load unbalance out-of-limit days in a single month is required to be brought into a treatment range. Wherein, the heavy load district with the single-phase maximum load rate exceeding 80% is used as a serious problem district, and effective measures are immediately taken for treatment; and other transformer areas are preferably treated by adopting operation and maintenance management measures according to the cause of the problem, and are brought into the distribution network infrastructure or technical improvement project plan if necessary, and are treated by adopting engineering or technical measures.

For the distribution area which is caused by the random change of special load and has unbalanced three-phase load and is still difficult to manage after the operation and maintenance management measures are taken, the three-phase load can be managed by adopting the automatic adjustment technical measures of the three-phase load.

The scheme for treating three-phase imbalance in the prior art mainly comprises a power electronic type three-phase load automatic adjusting device (hereinafter referred to as scheme 1), a capacitance type three-phase load automatic adjusting device (hereinafter referred to as scheme 2) and a commutation switch type three-phase load automatic adjusting device (hereinafter referred to as scheme 3), wherein the three modes have advantages and disadvantages, so that how to exert advantages and how to make up the disadvantages are the problems to be solved at present. The three schemes are as follows:

scheme 1:

the power electronic three-phase load automatic regulating device (BSVG) is a comprehensive control device for power quality by adopting a high-power turn-off power electronic switch technology. The method is characterized in that reactive, negative sequence and harmonic current at an access position are quickly detected, and a trigger pulse signal is generated according to a Space Vector Pulse Width Modulation (SVPWM) control method to drive and control a thyristor to output compensation current which is equal to the detected reactive, negative sequence and harmonic current in magnitude and opposite in direction, so that the problems of reactive, harmonic and voltage fluctuation, three-phase load unbalance and the like of a power distribution area are comprehensively solved.

The advantages are that:

the unbalance compensation capability is strong, the modules can be overlapped, and the unbalance compensation capability is theoretically unlimited;

the unbalance adjustment capability is strong, and the unbalance can be controlled to be less than 5% (in a capacity range);

the whole machine has high efficiency, and the efficiency is more than or equal to 97.5% when the whole machine is fully loaded;

the response time is short, and is less than 10 ms;

perfect protection function;

the protection circuit has the functions of overvoltage protection, undervoltage protection, open-phase protection, short-circuit protection, over-compensation protection, lightning protection dual protection and the like;

bidirectional reactive compensation is adopted, and the power factor is improved.

Disadvantages are that:

only unbalanced current at the low-voltage side of the distribution transformer can be balanced, and the condition of unbalanced load current cannot be fundamentally improved;

there is a certain power loss;

the heat generation is large;

when in operation, the noise is large;

at present, the equipment cost is high and cannot be kept due to the influence of the technology.

Scheme 2:

the capacitive three-phase load automatic regulating device (interphase bridging capacitance reactive power compensation device) is characterized in that a power capacitor is bridged between phase lines, active power transfer is realized, interphase active power is balanced, meanwhile, unequal reactive power compensation is carried out on each phase by the power capacitor connected between the phase lines and a zero line, the interphase reactive power is balanced, the three-phase unbalance degree is reduced, and the power factor is improved.

The advantages are that:

the reactive power is compensated, meanwhile, the transfer of active power can be realized, and the unbalance degree of three phases is reduced;

the capacitor is adopted as the adjusting equipment, so that the cost is lower, the technology is mature, the realization is easy, and the loss is small;

disadvantages are that:

the device is only suitable for places with large reactive load and has limited adjusting capacity;

only coarse adjustment is needed, and fine adjustment is difficult to achieve.

Scheme 3:

the phase-change switch type three-phase load automatic regulating device (low-voltage load automatic phase-change device) is formed from an intelligent phase-change terminal (responsible for load monitoring and automatic phase-change control) and several phase-change switch units (responsible for executing load phase-change operation mechanism). The intelligent phase change terminal monitors three-phase current of the distribution transformer low-voltage outgoing line in real time, if three-phase load unbalance degree of a distribution transformer low-voltage side exceeds the limit in a certain monitoring period, the intelligent phase change terminal reads current and phase sequence real-time data of the distribution transformer low-voltage outgoing line and load branches of all phase change switch units, optimization calculation is carried out, an optimal phase change control instruction is sent out, the phase change switch units execute phase change operation according to a specified phase change flow, and user load phase sequence adjustment and three-phase load balanced distribution of a power distribution area are achieved.

The advantages are that:

the unbalance degree can be reduced from the load side;

the power consumption is low;

the calorific value is low.

Disadvantages are that:

only coarse adjustment is needed, and accurate adjustment is difficult to achieve;

the response time is slow and the actions cannot be done too frequently.

In summary, there are technical problems of different degrees in all the above 3 schemes. Therefore, the present invention provides a device for optimizing power quality of a cell based on regional wireless communication, so as to overcome at least some of the above technical problems.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the utility model provides a district power quality optimizing device based on regional wireless communication to solve at least some technical problems.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a transformer area power quality optimization device based on area wireless communication comprises an SVG module connected between a transformer and a load, a phase change controller connected between the transformer and the load, and a phase change switch device connected between the transformer and the load.

Further, the commutation switch device comprises a magnetic latching relay CJ1 connected to the A-phase line connected to the transformer, a triac VS1 connected in parallel to the magnetic latching relay CJ1, a magnetic latching relay CJ2 connected to the B-phase line connected to the transformer, a triac VS2 connected in parallel to the magnetic latching relay CJ2, a magnetic latching relay CJ3 connected to the C-phase line connected to the transformer, a triac VS3 connected in parallel to the magnetic latching relay CJ3, and loads connected to the magnetic latching relay CJ1, the magnetic latching relay CJ2, the magnetic latching relay CJ3 and the N-phase line connected to the transformer, respectively.

Further, the SVG module comprises a first SVG unit and a second SVG unit which are connected between the transformer and the load, and a driving control module which is respectively connected with the two SVG units.

Furthermore, the drive control module comprises a controller and an IGBT driver connected out of the controller, and the IGBT driver is respectively connected with the two SVG units.

Furthermore, the first SVG unit comprises three SVG subunits which are connected in parallel, and the second SVG unit comprises three SVG subunits which are connected in parallel; the SVG subunit comprises a diode VD and a triode MOS, the cathode and the anode of the diode VD are respectively connected with the collector and the emitter of the triode MOS, and the IGBT driver is connected with the base of the triode MOS.

Further, the anode and the cathode of the diode VD in the first SVG unit are connected to the cathode and the anode of the diode VD in the second SVG unit, respectively.

Furthermore, an A phase line connected out of the transformer is respectively connected with the first SVG unit and the second SVG unit through a first lead, and preferably, the first lead is connected with an anode of a diode VD in the first SVG unit and a cathode of the diode VD in the second SVG unit;

the B-phase line connected out of the transformer is respectively connected with the first SVG unit and the second SVG unit through a second wire, and preferably, the second wire is connected with the anode of a diode VD in the first SVG unit and the cathode of the diode VD in the second SVG unit;

the C-phase line connected out of the transformer is respectively connected with the first SVG unit and the second SVG unit through a third wire, preferably, the third wire is connected with the anode of a diode VD in the first SVG unit and is connected with the cathode of the diode VD in the second SVG unit;

and the N phase line connected out of the transformer is respectively connected with the first SVG unit and the second SVG unit through a fourth wire.

Furthermore, a fourth wire is respectively connected with the anode of a diode VD in the first SVG unit; preferably, the fourth wires are also respectively connected with cathodes of the diodes VD in the second SVG unit.

Further, a fourth lead is respectively connected with the cathodes of the diodes VD in the first SVG unit through capacitors C1; preferably, the fourth line is also connected to the anodes of the diodes VD in the second SVG unit via a capacitor C2, respectively.

Further, the load is a single-phase user.

Compared with the prior art, the invention has the following beneficial effects:

the three-phase unbalance regulation device has the advantages of simple structure, scientific and reasonable design and convenient use, effectively overcomes the defects of high cost, large operation noise and large electric energy loss of the SVG as three-phase unbalance regulation by organically combining the SVG and the phase change switch, and can well apply the phase change switch to realize load switching and fundamentally solve the unbalanced condition. The advantages of the two are complementary, the advantages are exploited, the disadvantages are avoided, and the good effect of treating the unbalance of three phases is achieved.

The invention comprehensively considers the factors of three-phase imbalance treatment cost, treatment effect, reactive compensation and the like, develops a three-phase imbalance comprehensive treatment scheme combining BSVG and the commutation switch, the commutation switch can automatically adjust three-phase load according to imbalance under the condition of not interrupting power supply of users, overcomes the defect that the traditional manual wire changing is used for adjusting the three-phase imbalance, can effectively reduce transformer loss and line loss caused by the imbalance of the three-phase load, and overcomes the conditions of overcurrent of a certain phase, low voltage at the tail end and the like and numerous potential safety hazards caused by the imbalance of the three phases. Meanwhile, the small-capacity SVG is arranged between the transformer and the load, and is adopted for effective supplement, so that the defect that the phase change switch can only carry out coarse adjustment is overcome, the three-phase imbalance condition can be better treated, and a good three-phase imbalance treatment effect can be realized even in the platform area environment with complex load condition and rapid change.

The multi-phase unbalanced current regulation system takes the MUC in the SVG module as a master control core, the SVG unit and the phase change controller communicate through RS485, three-phase unbalanced current is uniformly and coordinately regulated, unbalanced rough regulation is carried out through the phase change switch, fine regulation and reactive compensation are carried out through the SVG, flexible combination is achieved, respective advantages of two regulation modes are considered, and meanwhile equipment cost is maximally reduced. The problem of low-voltage power grid power quality is solved fundamentally, power supply reliability is improved, loss of a power distribution network is reduced, workload of operation and maintenance personnel for field inspection and load adjustment is reduced, and working efficiency is improved.

Drawings

Fig. 1 is an electrical schematic of the present invention.

Fig. 2 is a schematic diagram of the phase change switch of the present invention.

Fig. 3 is a front view of the protective housing of the present invention.

Fig. 4 is a side view of the protective housing of the present invention.

Fig. 5 is a schematic view of the protective housing of the present invention mounted on an electric pile.

Fig. 6 is a top side view of the protective housing of the present invention mounted to an electrical pile.

Fig. 7 is a layout of the elements within the protective enclosure of the present invention.

Fig. 8 is a schematic diagram of a three-phase imbalance adjustment controller according to the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to the accompanying drawings. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation or be constructed and operated in a particular orientation, and thus, it should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; of course, mechanical connection and electrical connection are also possible; alternatively, they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

As shown in fig. 1-8, the station area power quality optimization device based on regional wireless communication provided by the invention has the advantages of simple structure, scientific and reasonable design and convenient use, effectively overcomes the defects of high cost, large operation noise and large power loss of the SVG as three-phase unbalance adjustment by organically combining the SVG and the phase change switch, and can well realize load switching by using the phase change switch, thereby fundamentally solving the unbalanced condition. The advantages of the two are complementary, the advantages are exploited, the disadvantages are avoided, and the good effect of treating the unbalance of three phases is achieved. The system comprises an SVG module connected between a transformer and a load, a phase change controller connected between the transformer and the load and a phase change switch device connected between the transformer and the load, wherein the load is a single-phase user. The commutation switch device comprises a magnetic latching relay CJ1 connected with an A-phase line connected with a transformer, a bidirectional thyristor VS1 connected with the magnetic latching relay CJ1 in parallel, a magnetic latching relay CJ2 connected with a B-phase line connected with the transformer, a bidirectional thyristor VS2 connected with the magnetic latching relay CJ2 in parallel, a magnetic latching relay CJ3 connected with a C-phase line connected with the transformer, a bidirectional thyristor VS3 connected with the magnetic latching relay CJ3 in parallel, and loads connected with the magnetic latching relay CJ1, the magnetic latching relay CJ2, the magnetic latching relay CJ3 and an N-phase line connected with the transformer respectively.

The SVG module comprises a first SVG unit and a second SVG unit which are connected between a transformer and a load, and a drive control module which is respectively connected with the two SVG units. The drive control module comprises a controller and an IGBT driver connected out of the controller, and the IGBT driver is respectively connected with the two SVG units.

The first SVG unit comprises three SVG subunits which are connected in parallel, and the second SVG unit comprises three SVG subunits which are connected in parallel; the SVG subunit comprises a diode VD and a triode MOS, the cathode and the anode of the diode VD are respectively connected with the collector and the emitter of the triode MOS, and the IGBT driver is connected with the base of the triode MOS. And the anode and the cathode of the diode VD in the first SVG unit are respectively connected with the cathode and the anode of the diode VD in the second SVG unit.

The A phase line connected out by the transformer is respectively connected with the first SVG unit and the second SVG unit through a first lead, and preferably, the first lead is connected with the anode of a diode VD in the first SVG unit and is connected with the cathode of the diode VD in the second SVG unit. A B-phase line connected out of the transformer is respectively connected with the first SVG unit and the second SVG unit through a second wire, and preferably, the second wire is connected with an anode of a diode VD in the first SVG unit and a cathode of the diode VD in the second SVG unit. The C-phase line connected out by the transformer is respectively connected with the first SVG unit and the second SVG unit through a third wire, and preferably, the third wire is connected with the anode of a diode VD in the first SVG unit and is connected with the cathode of the diode VD in the second SVG unit. The N phase line connected out by the transformer is respectively connected with the first SVG unit and the second SVG unit through a fourth wire.

The fourth wire is respectively connected with the anode of a diode VD in the first SVG unit; preferably, the fourth wires are also respectively connected with cathodes of the diodes VD in the second SVG unit. The fourth lead is respectively connected with the cathode of a diode VD in the first SVG unit through a capacitor C1; preferably, the fourth line is also connected to the anodes of the diodes VD in the second SVG unit via a capacitor C2, respectively.

The technical parameters of each electrical device of the present invention are shown in table 1.

TABLE 1 technical parameters

The BSVG product is arranged in a shell, the shell is shown in figures 3 and 4, the power grade of the BSVG product ranges from 20Kvar to 150Kvar, 5 different sizes exist according to the power grade, and the specific external dimension is shown in Table 2

TABLE 2 external dimension table of device

The present invention is shown in fig. 5 and 6 when installed outdoors. When the device is installed outdoors, firstly, the pulley is hung on a cross arm of a telegraph pole, then a rope passes through the pulley and is tied on hanging rings on two sides of a cabinet of the device, and the cabinet is pulled to the air over 2.5 meters away from the ground in a manual or mechanical pulling mode; the mounting bracket is fixed by a U-shaped hoop, the hoop screw is provided with 2 nuts and an elastic and flat cushion (or square cushion), and the locking is firm; secondly, the bottom of the box body is connected with the support through six M12 x 40 bolts, the upper surface of the angle steel is provided with an elastic flat pad, and the lower surface of the angle steel is provided with a flat pad and a nut; and finally, performing grounding treatment on the case body shell. Tools required for installation: 2 # open spanner, pulley/crane, safety cable and pole climbers.

When the invention is used for wiring, all power wires penetrate into the equipment through the bottom wire inlet hole, and all mutual inductor cables enter the equipment through the bottom circular hole. Wiring is carried out according to the diagram shown in fig. 1, and a power cable access point of the equipment is arranged between a check point on the low-voltage side of the transformer and a load (a BSVG main cable is connected to the power side of the newly-added sampling transformer, and a jumper capacitor main cable is connected to the load side of the newly-added sampling transformer); the current transformer is installed on the load side (i.e. between the power cable access point and the user load), P2 is towards the transformer side, P1 is towards the load side, and the transformer sampling line is connected to the corresponding terminal in the machine. The phase-change controller is installed in the SVG cabinet and shares a group of CTs with the SVG, RS485 communication is adopted between the phase-change controller and the SVG cabinet, and data interaction is realized. Zigbee wireless communication is adopted between the phase change controller and the phase change switch, the phase change controller monitors the unbalanced current of the transformer area and comprehensively analyzes the load condition transmitted back by the phase change switch, an optimal regulation scheme is obtained, and the phase change operation is carried out on the corresponding switch according to the command.

According to the invention, when cables are selected, the multi-core armored cable is recommended to be selected for the power cable, the specification of the cable refers to table 3, and during wiring, the specification of the cable at least meets the recommended value, otherwise, the cable is possibly heated and aged to cause equipment damage.

TABLE 3 Power Cable recommended Specification (KVV)

Remarking: the cables recommended in the table are copper-core cables, and if aluminum-core cables are used, the conversion is performed according to relevant regulations.

When the current sampling transformer is selected, the current transformer needs to meet the following electrical parameters:

rated secondary current is 5A;

rated secondary power is greater than 1 VA;

the measurement precision of the mutual inductor is at least 0.5 grade;

CT transformation ratio range: 150/5-6000/5, the CT rated current is selected according to 1.5 times of the system current. The cable of the mutual inductor is recommended to be a twisted pair cable (RVVP) with a shielding, wherein the inner diameter of 15m is 2.5mm2, and the inner diameter of 15 m-30 m is 4mm 2.

The design principle of the invention is to finally enable the user to realize the unbalance adjustment function of the invention through minimum operation. Before leaving the factory, the equipment enters the line of basic parameter setting, and a user only needs to correctly wire, electrify, set the CT transformation ratio and start the machine.

When the BSVG equipment is electrified, the operation steps are as follows:

(1) and fixing and connecting the equipment with the power cable and the signal cable.

(2) A main circuit breaker closing the BSVG and across the capacitor, respectively, and a miniature circuit breaker.

At this time, the LCD display screen of the BSVG part is lit. The lower left corner of the front panel is sequentially provided with a fault (red), an operation (green) and a power supply (green) indicator lamp from left to right. If the equipment is normally powered on, the power indicator lamp is lightened; if the equipment has a fault, the fault indicating lamp can display red color and cannot be normally started. And the cross-over capacitor part enters an automatic working mode when the machine is started, and automatically operates according to preset parameters.

(3) Manual/automatic start

After the BSVG is powered on for the first time, manual start is needed to realize compensation in order to ensure safety. After the equipment is started, the running indicator lamp is lightened. After normal compensation is possible, the device can be set to power on for automatic start.

(4) Shutdown step

The shutdown mode is a complete shutdown mode, namely after shutdown, the system is uncharged, and related maintenance work of the system can be carried out (note that after a module cover plate is opened, the direct-current bus is strictly prohibited to touch); the other mode is to use the setting of the LCD control panel to perform shutdown, and the shutdown mode is only to shut down the operation of the power device in the system, and the machine is in a standby state.

The BSVG equipment is controlled through the LCD screen, and the front panel of the equipment comprises a 4.3-inch LCD touch screen (HMI). The screen can display the current power grid voltage, current, compensation current, module temperature and other information, and can perform parameter setting, startup and shutdown and the like through the screen.

The invention can be remotely monitored through WIFI, and the user can also log in a browser to remotely monitor through WiFi of mobile equipment (mobile phone, PAD) connecting equipment.

WiFi connection and setup

(1) Finding a wireless network with the network name of 'admin' in a 'setting-wireless local area network' of a mobile phone or a PAD, clicking to connect, inputting a password: admin, waiting for the wireless connection to succeed;

(2) opening a mobile phone browser, and inputting an IP address in an address bar: 192.168.3.1, click to log in;

(3) inputting a user name: mxchip, password: 12345678, click to log in;

(4) the WIFI display interface is divided into 4 areas: basic, setup, alarm, and related. "basic" displays information such as grid voltage, frequency, grid current, load current, compensation current, grid side power, load side power, etc.

The invention relates to an intelligent phase-change switch which is a product developed by our company and used for treating three-phase unbalance. The three-phase four-wire system low-voltage distribution system is suitable for a 380V/220V low-voltage distribution system of a three-phase four-wire system, can automatically adjust three-phase loads according to the unbalance degree under the condition of not interrupting power supply of a user, and overcomes the defect that the traditional method depends on manual wire changing to adjust three-phase unbalance. The product can effectively reduce transformer loss and line loss caused by unbalanced three-phase load, and overcome the conditions of overcurrent, low voltage at the tail end and the like of a certain phase and numerous potential safety hazards caused by unbalanced three phases. The technical parameters of the intelligent phase-change switch are shown in table 4.

TABLE 4 Intelligent commutation switch technical parameters

The intelligent phase change switch comprises a phase change controller and a phase change switch: the phase-change controller is an intelligent control device integrating sampling, operation, communication, man-machine interaction, intelligent networking and balance logic algorithm. The phase change switch is an intelligent switching device integrating sampling, operation, communication and phase sequence switching functions.

The invention can automatically balance the three-phase load, monitor the three-phase unbalance in real time, automatically adjust the three-phase load according to the unbalance, has the phase change time less than or equal to 20ms, does not interrupt the power supply of a user, does not cause the resetting and restarting of common electrical appliances, and does not damage the electrical appliances.

The invention can reduce the transformer loss, so that the transformer is in a symmetrical running state, and the transformer loss is effectively reduced.

The invention can reduce the line loss and effectively reduce the neutral line current, thereby reducing the loss of the neutral line and the loss of the phase line.

The invention can solve the problems of low voltage and overvoltage, solve the problems of low voltage and overvoltage caused by three-phase unbalance and avoid burning out the electric equipment due to overvoltage or influencing the normal operation of the electric equipment due to low voltage.

The invention can protect the safe operation of the low-voltage distribution network, avoid the heating and the aging loss caused by the over-high neutral current for a long time and avoid the hidden trouble of burning the distribution equipment such as a transformer and the like.

The invention can be maintenance-free and management-free, and does not need special maintenance and management after the system is put into operation, thereby saving manpower and material resources and improving efficiency.

The invention can automatically change the phase without interrupting the power supply of the user. 1) Automatic commutation is realized without manual participation; 2) the commutation time is less than or equal to 20ms, and the power supply interruption can not be caused

The invention discloses a reliable interphase short circuit prevention technology, 1) a reliable hardware locking technology, which prevents a plurality of phase sequences from being simultaneously switched on; 2) multiple software algorithms intelligently prevent interphase short circuit.

The switch element of the invention consumes no power, the power consumption of the device is small, 1) a permanent magnet relay mechanism is adopted, the device operates without pressure, and 2) the power consumption of the device is less than or equal to 8W.

The invention is provided with a phase conversion controller which is arranged in a transformer area and is responsible for monitoring three-phase unbalance information and issuing an adjusting command; the phase change switch is installed at the front end of the user along the line, can monitor the load information of the loaded loop of the user, and carries out corresponding phase change operation according to a phase change command issued by the phase change controller.

The YCSPS series intelligent phase change switches are communicated in a zigzag mode, each main control switch is only responsible for communicating with the phase change switches of the same branch, one branch forms a subsystem, the main control switch serves as a host, and the phase change switches serve as slaves.

The invention develops a unique intelligent networking mechanism, namely a preemptive time-sharing communication mechanism, aiming at a mode that multiple main control switches share the network, and the mechanism avoids the conflict and the interference of carrier communication among different branches and realizes the intelligent networking function.

The algorithm selected by the invention is a balance algorithm principle based on mathematical recursive logic, and when the main control switch monitors that the unbalance degree of the branch circuit per se exceeds a set value, the balance logic algorithm is started.

Because the power load of each user is different and the unbalance degree of each branch is different, the method is based on the principle of a mathematical recursive logic algorithm, combines the balance regulation requirement and the load size of each commutation switch, performs logic combination operation, and solves an optimal strategy.

Based on the principle of a balancing algorithm of branch balancing strategies, after the main control switch in each branch calculates the optimal strategy, the phase change switch in the branch is instructed to carry out corresponding phase change operation, so that the branch balancing is realized. And each branch in the transformer area reaches a three-phase balance state, so that the three-phase balance of the transformer can be realized.

The essence of the invention that the phase sequence is switched in a very short time without power failure and phase commutation is as follows:

1) actuating element

The phase change switch adopts a permanent magnet relay as an action element.

The permanent magnet relay has the characteristics of strong loading capacity, low power consumption, high action speed, low loss, reliable operation, low cost and the like. Based on the characteristics of the permanent magnet relay, the commutation switch realizes the function of no-power-off commutation, the interruption of power supply of a user can not be caused in the commutation process, and the power supply quality is ensured.

Through a large amount of theoretical investigation and actual measurement verification, the power failure time of 30ms cannot cause the power failure of the electric equipment, and the phase change time of the XY-Q220 phase change switch is less than or equal to 20ms, so that the application requirement is completely met.

2) Zero crossing commutation

In order to guarantee the service life, the commutation switch adopts a zero-crossing switching technology so as to reduce the damage of switching on and off to action elements to the minimum. The zero-crossing switching technology is based on the principle of 'current zero-crossing cutting and voltage zero-crossing switching', and can achieve the effects of extremely small impact and extremely small electric arc.

The phase-change switch device is arranged near a tower pole at the output end of a transformer or a user ammeter box, measures three-phase voltage and current phase current in real time through a voltage transducer and a current transducer, calculates active power, reactive power, power factor, current phase and phase-change action times, and reports related information to a phase-change controller in a timed mode through a ZigBee wireless transparent transmission network and the like. The device can realize switching in the twinkling of an eye without power failure, and the switching is kept by the relay, realizes the switching with load, and switching time is little and is done for 20ms, can not cause the outage to user equipment.

According to the invention, by organically combining the SVG and the commutation switch, the defects of high cost, high operation noise and large electric energy loss of the SVG as three-phase unbalance adjustment are effectively solved, and meanwhile, the commutation switch can be well applied to realize load switching, so that the unbalanced condition is solved fundamentally. The advantages of the two are complementary, the advantages are exploited, the disadvantages are avoided, and the good effect of treating the unbalance of three phases is achieved.

Finally, it should be noted that: the above embodiments are only preferred embodiments of the present invention to illustrate the technical solutions of the present invention, but not to limit the technical solutions, and certainly not to limit the patent scope of the present invention; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention; that is, the technical problems to be solved by the present invention, which are not substantially changed or supplemented by the spirit and the concept of the main body of the present invention, are still consistent with the present invention and shall be included in the scope of the present invention; in addition, the technical scheme of the invention is directly or indirectly applied to other related technical fields, and the technical scheme is included in the patent protection scope of the invention.

Claims

1. The utility model provides a platform district electric energy quality optimizing apparatus based on regional radio communication which characterized in that: the device comprises an SVG module connected between a transformer and a load, a phase change controller connected between the transformer and the load, and a phase change switch device connected between the transformer and the load.

2. The device of claim 1, wherein the device comprises: the commutation switch device comprises a magnetic latching relay CJ1 connected with an A-phase line connected with a transformer, a bidirectional thyristor VS1 connected with the magnetic latching relay CJ1 in parallel, a magnetic latching relay CJ2 connected with a B-phase line connected with the transformer, a bidirectional thyristor VS2 connected with the magnetic latching relay CJ2 in parallel, a magnetic latching relay CJ3 connected with a C-phase line connected with the transformer, a bidirectional thyristor VS3 connected with the magnetic latching relay CJ3 in parallel, and loads connected with the magnetic latching relay CJ1, the magnetic latching relay CJ2, the magnetic latching relay CJ3 and an N-phase line connected with the transformer respectively.

3. The device of claim 1, wherein the device comprises: the SVG module comprises a first SVG unit and a second SVG unit which are connected between the transformer and the load, and a drive control module which is respectively connected with the two SVG units.

4. The device of claim 3, wherein the device comprises: the drive control module comprises a controller and an IGBT driver connected out of the controller, and the IGBT driver is respectively connected with the two SVG units.

5. The device of claim 4, wherein the device comprises: the first SVG unit comprises three SVG subunits which are connected in parallel, and the second SVG unit comprises three SVG subunits which are connected in parallel; the SVG subunit comprises a diode VD and a triode MOS, the cathode and the anode of the diode VD are respectively connected with the collector and the emitter of the triode MOS, and the IGBT driver is connected with the base of the triode MOS.

6. The device of claim 5, wherein the device comprises: and the anode and the cathode of the diode VD in the first SVG unit are respectively connected with the cathode and the anode of the diode VD in the second SVG unit.

7. The device of claim 6, wherein the device comprises: the A phase line connected out by the transformer is respectively connected with the first SVG unit and the second SVG unit through a first wire, preferably, the first wire is connected with the anode of a diode VD in the first SVG unit and is connected with the cathode of the diode VD in the second SVG unit;

8. The device of claim 7, wherein the device for optimizing power quality of the cell based on the regional wireless communication comprises: the fourth wire is respectively connected with the anode of the diode VD in the first SVG unit; preferably, the fourth wires are also respectively connected with cathodes of the diodes VD in the second SVG unit.

9. The device of claim 8, wherein the device for optimizing power quality of the cell based on the regional wireless communication comprises: the fourth lead is respectively connected with the cathode of a diode VD in the first SVG unit through a capacitor C1; preferably, the fourth line is also connected to the anodes of the diodes VD in the second SVG unit via a capacitor C2, respectively.

10. The device of claim 1, wherein the device comprises: the load is a single-phase user.