Power System Voltage Level and Substation Type
The power system voltage levels are 220/380V (0.4 kV), 3 kV, 6 kV, 10 kV, 20 kV, 35 kV, 66 kV, 110 kV, 220 kV, 330 kV, and 500 kV. With the improvement of motor manufacturing technology, 10 kV motors have been mass-produced, so 3 kV and 6 kV have been used less frequently, and 20 kV and 66 kV are rarely used. The power supply system is mainly based on 10 kV and 35 kV. The transmission and distribution system is mainly above 110 kV. Power plant generators are available in two types, 6 kV and 10 kV, and are now based on 10 kV. The users are 220/380 V (0.4 kV) low-voltage systems.
According to the “Regulations for the Design of Urban Electric Power Networkâ€, the transmission network is 500 kV, 330 kV, 220 kV, 110 kV, the high-voltage distribution network is 110 kV, 66 kV, and the medium-voltage distribution network is 20 kV, 10 kV, 6 kV, low-voltage distribution network. It is 0.4 kV (220V/380V).
The power plant emits 6 kV or 10 kV electricity. In addition to the power plant's own use (plant power), it can also be sent to users near the power plant with a 10 kV voltage. The 10 kV power supply range is 10Km and 35 kV is 20~50Km. 66 kV is 30~100Km, 110kV is 50~150Km, 220kV is 100~300Km, 330kV is 200~600Km, 500kV is 150~850Km.
2. Types of substations
Various voltage levels of the power system are converted by a power transformer, and the voltage is boosted by a step-up transformer (substation is a booster station), and the voltage is reduced by a step-down transformer (substation is a step-down station). A two-turn transformer that selects two coils (windings) whose voltage becomes another voltage, a three-turn transformer that uses three coils (windings) for two voltages.
Substations are divided into hub stations, regional stations and terminal stations in addition to step-up and step-down. Hub voltage levels are generally three (three-turn transformers), 550kV/220kV/110kV. Regional stations also generally have three voltage levels (three-turn transformers), 220 kV/110kV/35kV or 110kV/35kV/10kV. Terminal stations are generally directly connected to users, most of which are two voltage levels (two-turn transformers) 110kV/10 kV or 35 kV/10 kV. The user's own substation generally has only two voltage levels (double-turn transformers) 110 kV/10 kV, 35 kV /0.4 kV, and 10 kV /0.4 kV, with 10 kV /0.4 kV being the most.
3. Substation primary circuit wiring scheme
1) One connection type
Substation primary circuit wiring refers to the interconnection of all electrical equipment (transformers, inlet and outlet switches, etc.) after the transmission line enters the substation. The wiring schemes are: line transformer group, bridge connection, single bus bar, single bus bar segment, double bus bar, double bus bar segment, ring network power supply and so on.
2) Line transformer group
The transformer substation has only one line and one transformer, and the line transformer group is used for wiring without any further development.
3) Bridge connection
There are two incoming lines, two transformers, and in the absence of further development, bridge-type wiring is used. For transformers, the contact breakers are internal bridge connections within the two incoming circuit breakers and the contact breakers are external bridge connections outside the two incoming circuit breakers.
4) Single bus
When there are many substations in and out of the substation, single busbars are used. When there are two lines entering the line, they are generally powered by one channel and all the way to standby (without power supply at the same time). The two devices can use the power supply to self-invest, and the multiple routes are led by a busbar.
5) Single bus segment
When there are two or more incoming lines and multiple outgoing lines, single bus bar segments are used. The two incoming lines are respectively connected to two bus bars, and the two bus bars are connected by a bus coupler switch. Outgoing lines were received on two busbars.
Single bus segmented operation mode is more. Normally, all the way to the main supply, all the way to standby (not closing), the mother combined, when the main supply for power, the standby closed, the main supply, standby and the mother interlocked. When the backup power supply capacity is small, after the backup power supply is closed, some outgoing lines must be disconnected. This is a more commonly used mode of operation.
For particularly important loads, the two lines are mainly supplied, and the bus switch is disconnected. When the line is disconnected from the line, the busbar is connected, and after the call is made, the busbar is disconnected and the line switch is closed.
The single busbar section is also conducive to internal maintenance of the substation. During maintenance, a section of busbars can be stopped. If the single busbar is not divided, the whole station should be powered off during maintenance. The bypass busbar can be used without power failure. The bypass busbar is only used for electricity. System substation.
6) Double bus
The double busbars are mainly used in power plants and large substations. Each circuit is connected to two busbars by a circuit breaker via two disconnectors. In this way, when the busbars are inspected and repaired, they can be used to switch the lines to a conditional busbar. on. The double busbars are also divided into two types: segmented and non-segmented. The double busbar segment is added with the bypass circuit breaker. The wiring mode is complex, but the overhaul is very convenient and the power outage range can be reduced.
4. Secondary circuit of substation
1) The type of secondary circuit
The secondary circuit of the substation includes: measurement, protection, control and signal loops. Measurement loops include: metering and protection measurements. The control loops include: manual manual opening/closing, anti-jump interlocking, testing, mutual investment interlocking, protection tripping, and closing/opening execution. The signal loop includes the switch operation status signal, accident trip signal and accident notice signal.
2) Measurement loop
Measurement loops are divided into current loops and voltage loops. The current loop equipment is connected in series to the secondary side (5A) of the current transformer. The current transformer is to convert the primary load current into a 5A measurement current. Metering and protection use their own transformers (measurement transformers with high precision requirements), metering measurements in series with the current meter and power meter, power meter and power factor meter current terminals. The protection measure is connected in series with the current terminal of the protection relay. Microprocessor protection generally focuses on metering and protection, with metering current terminals and protection current terminals, respectively.
Voltage measurement circuit, 220/380V low voltage system directly connected to 220V or 380V, 3KV high voltage system all through the voltage transformer to various levels of high voltage into a unified 100V voltage, voltmeter and power meter, power meter and power factor The voltage coil of the watch is connected to the 100V voltage bus via its terminals. Microprocessor protection unit measurement voltage and protection voltage are unified as a voltage terminal.
3) Control loop
(1) Coupling circuit
Opening and closing gates are operated by opening and closing the transfer switch. Conventional protection is required to prompt the operator and the accident tripping alarm. The transfer switch selects the pre-closing-closing-closing and pre-separating-breaking-separating multi-shifting switch. In order to make use of the non-corresponding wiring for the opening and closing prompts and accident tripping alarms, the country has a standard diagram design. After the microcomputer protection is used, after the remote switching operation is performed, the switching operation of the switch is performed on the spot. This loses the significance of the remote operation. Therefore, it is necessary to cancel the non-corresponding wiring and use only the intermediate reset. Gate and opening the third gear switch.
(2) Anti-jump circuit
When the closing circuit fails, it will be opened, or the short circuit accident will not be eliminated, and the closing (misoperation) will occur again. At this time, the circuit breaker will be opened and reversed, which will not only easily cause or expand the accident, but also cause damage to the equipment. Or personal accidents, so the high-voltage switch control loop should be designed to prevent jumps. Anti-jump generally uses current-start, voltage-holding dual-coil relays. The current coil is connected in series with the opening circuit as a starting coil. The voltage coil is connected to the closing circuit as a holding coil. When it is opened, the current coil is started through the opening circuit. If the closing circuit is faulty or in the manual closing position, the voltage coil starts and is self-retained through its normally open contact. The normally closed contact immediately opens the closing circuit, ensuring that the circuit breaker cannot be reclosed during the opening process. brake. The current loop of the anti-trip relay can also self-hold the current coil through its normally open contact, which can reduce the disconnection of the output contact of the protection relay and also reduce the protection relay's holding time requirement.
Some microcomputer protection devices have their own anti-hop function, so that it is no longer possible to design an anti-skipping circuit. When the circuit breaker operating mechanism selects the spring energy storage, if the energy storage device is selected after energy storage, it can perform a spring energy storage operating mechanism which is closed and opened once (there is also a spring for secondary closing and opening after energy storage for reclosing. Energy storage operating mechanism), because the energy storage generally requires about 10 seconds, when the energy storage switch is often in the disconnected position, store one energy, after the completion of the energy storage switch is again in the off position, you can jump once the gate; After the trip, manual energy storage must be performed before closing. In this case, the anti-trip loop may not be designed.
(3) Interlocking and controlling test and mutual investment
For handcart switchgear, after the handcart is rolled out, it is necessary to conduct a breaker breakage test. The breakout test button should be designed. Line breaks into line with the mother, generally should be interlocked or controlled according to the requirements of the mutual investment.
(4) Protection trip
The protection trip outlet is connected to the trip circuit through the connection piece. The connection piece is used for protection debugging, or some protection functions are released during operation.
(5) Coupling circuit
The merging and opening circuit provides the power supply for the operating mechanism for the merging and opening and closing bus, and its control circuit should generally be drawn separately.
4) Signal loop
(1) The switch operation status signal is composed of two lights installed on the switchgear by the switch-on and switch-off indications: after the operation switch is not wired, it is connected to the positive power supply. After adopting the protection of the microcomputer, the conversion switch cancels the non-corresponding wiring, so the positive pole of the signal lamp can be directly connected to the positive power supply.
(2) The accident signal has two signals of accident tripping and accident notice. The accident tripping alarm also needs to pass the conversion switch and does not correspond to the accident trip signal bus, and then leads to the central signal system. The accident notice signal leads to the central signal system through the signal relay contacts. After the microcomputer protection is used, the contacts of the auxiliary contact of the circuit breaker operating mechanism and the signal relay are respectively connected to the digital input terminals of the microprocessor protection unit. If a central signal system is required, the microcomputer protection unit can provide accidental output contacts for accident trips and accidents. It can be led to the central signal system. Otherwise, the other signal contact relay should be used to lead to the central signal system.
(3) The central signal system is a centralized alarm system installed in the duty room. It consists of two sets of sound and light alarms: accidental tripping and accident notice. The optical alarm uses optical signs, no signal lights, and the light-word licenses are divided into two groups: scattered and dispersed. After adopting the substation integrated automation system, the central signal system can no longer be designed or simplified, and only centralized alarms are designed as backup alarms for computer alarms.
5. Relay protection of substation
1) The role of relay protection in substations
Transformer substation relay protection can malfunction (three-phase short circuit, two-phase short circuit, single-phase earthing, etc.) and abnormal phenomena (overload, overvoltage, low voltage, low frequency) during operation of the substation. , gas, over temperature, control and measurement loop breakage, etc.), promptly and selectively issue a trip command to cut off the fault or issue an alarm, thereby reducing the power outage range caused by the fault and the degree of damage to electrical equipment to ensure stable operation of the power system.
2) Basic working principle of relay protection in substations
The relay protection of the substation is based on the current increase, voltage increase or decrease, frequency decrease, occurrence of gas, temperature rise, etc., occurring during the operation of the substation, which exceeds the setting value of the relay protection (given After the value) or the over limit value, a trip command or alarm signal is selectively issued during the setting time.
The selective trip based on the current value is inverse time, and the higher the current value, the faster the trip. Selective tripping according to time is called definite time limit protection. The definite time limit will only appear after the set value of time has elapsed after the fault current exceeds the set value. Gas and temperature are non-electrical protection.
The reliability coefficient is an empirical data. When calculating the relay protection action value, the calculation result is multiplied by a reliable coefficient to ensure the relay protection operation is accurate and reliable. The range is 1.3~1.5.
The ratio between the minimum value at the time of fault and the action value of the protection is the sensitivity coefficient of the relay protection, which is generally 1.2~2, and should be selected according to the design specifications.
3) Classification of relay protection at transmission and distribution stations according to the nature of protection
4) Substation relay protection is classified according to protected objects
(1) Generator protection
The generator protection has stator winding phase-to-phase short circuit, stator winding grounding, stator winding inter-turn short circuit, generator external short circuit, symmetrical overload, stator winding over-voltage, excitation circuit one-to-two earthing, and loss of magnetization fault. The exit method is shutdown, delisting, narrowing the scope of faults and signaling.
(2) Power transformer protection
Power transformer protection has phase-to-phase short-circuits between the windings and their terminals, single-phase short-circuit at the neutral side of the neutral point, short-circuit between windings, overcurrent caused by an external short circuit, overcurrent caused by external grounding short-circuit in the neutral grounded power grid and Over-voltage, overload, oil level, transformer temperature, tank pressure, or cooling system failure.
(3) Line protection
Line protection According to the different voltage levels, the neutral point of the power grid is different, and the length of the transmission line and the cable or overhead line are different. There are: phase-to-phase short circuit, single-phase grounding short circuit, single-phase grounding, and overload.
(4) bus protection
Busbars in power plants and important substations shall be provided with special busbar protection.
(5) Power capacitor protection
The power capacitor has a capacitor internal fault and a short circuit at the lead-out line, a short circuit between the capacitor bank and the circuit breaker, an over-voltage caused by the removal of a fault capacitor in the capacitor bank, an over-voltage of the capacitor bank, and a voltage loss of the connected bus.
(6) High-voltage motor protection
High-voltage motors have stator winding phase-to-phase short circuits, stator windings single-phase grounding, stator winding overload, stator windings low voltage, synchronous motor step-out, synchronous motor demagnetization, and synchronous motor non-synchronous surge currents.
6. Microprocessor protection device
1) The advantages of microcomputer protection
(1) High reliability: A microcomputer protection unit can perform multiple protection and monitoring functions. Instead of a variety of protective relays and measuring instruments, the wiring of the switchgear cabinet and the control panel is simplified, thereby reducing the troubles of related equipment and improving the reliability. The microcomputer protection unit uses highly integrated chips. The software has automatic detection and automatic error correction, and it also improves the reliability of protection.
(2) High precision, high speed, and many functions. The digitization of the measurement part greatly improves its accuracy. The increase in CPU speed can enable various events to be timed in ms. The improvement of software functions can accomplish various protection functions through various complicated algorithms.
(3) With great flexibility, the protection and control features can be easily changed through software, and various interlocks can be realized through logic judgment. One type of hardware utilizes different software and can constitute different types of protection.
(4) Convenient for maintenance and debugging, less types of hardware, unification of lines, and simple external wiring, which greatly reduce the maintenance workload. The protection debugging and setting are carried out by using the input keys or the computer above, and debugging is simple and convenient.
(5) The economy is good, and the ratio of performance to price is high. Due to the versatility of the microcomputer protection, the overall cost of measurement, control and protection of the substation is reduced. High reliability and high speed can reduce power outage time, save manpower, and increase economic efficiency.
2) Features of Microprocessor Protection Devices
In addition to the advantages of the above-mentioned microcomputer protection, the microcomputer protection device has the following characteristics compared with similar products:
(1) Complete varieties: Microcomputer protection devices are especially complete in variety and can meet various protection requirements for various types of equipment in various types of substations, which provides great convenience for the design of substations and computer networks.
(2) The hardware adopts the latest chip to improve the technical advancement. The CPU adopts 80C196KB, measures 14-bit A/D conversion, and has up to 24 analog input loops. The acquired data is processed by the DSP signal processing chip. Using high-speed Fourier transform, the harmonics from the fundamental wave to the 8th harmonic are obtained, and the special software automatically corrects it to ensure the high precision of the measurement. Using dual-port RAM and CPU to transform data, it forms a multi-CPU system, and the communication adopts CAN bus. With a high communication rate (up to 100MHZ, generally running at 80 or 60MHZ) and strong anti-interference ability. Through the keyboard and liquid crystal display unit can be easily observed on the spot and a variety of protection and protection parameters set.
(3) Hardware design Special isolation and anti-jamming measures are adopted for power supply, analog input, digital input and output, communication interface, etc. The anti-interference ability is strong. In addition to the centralized group screen, it can be directly installed on the switchgear.
(4) The software is rich in functions. In addition to accomplishing various measurement and protection functions, it can complete fault recording (with 1 second high-speed fault recording and 9 seconds fault dynamic recording) through cooperation with the host computer, harmonic analysis and low current grounding. Line selection and other functions.
(5) The RS232 and CAN communication modes can be selected to support multiple telecontrol transmission protocols to facilitate networking with various computer management systems.
(6) Wide temperature background 240 × 128 large-screen LCD liquid crystal display, easy to operate, beautiful display.
(7) High integration, small size, light weight, convenient for centralized group screen installation and decentralized installation on switchgear.
3) The scope of use of microcomputer protection devices
(1) Small and medium-sized power plants and their boost substations.
(2) 110 kV / 35 kV /10 kV regional substation.
(3) 10 kV open and close gates of 10 kV power grids in cities
(4) User 110kV/10kV or 35kV/10kV total step-down station.
(5) 10kV substation
4) Types of Microcomputer Protection Devices
(1) There are four types of microcomputer protection devices.
(2) Line protection device
Microcomputer line protection device Microcomputer capacitance protection device Microcomputer direction line protection device
Microcomputer zero sequence distance line protection device microcomputer horizontal current line direction line protection device
(3) Main equipment protection device
Microcomputer two-winding transformer differential protection device microcomputer three-winding transformer differential protection device
Microcomputer transformer backup protection device Microcomputer generator differential protection device Microcomputer generator backup protection device
Microcomputer generator backup protection device Microcomputer motor differential protection device Microcomputer motor protection device
Microcomputer factory (station) change protection device
(4) Measurement and control device
Microcomputer telemetry remote control device Microcomputer remote control remote control device Microcomputer remote adjustment device Microcomputer automatic quasi synchronization device
Microcomputer preparation device Microcomputer PT switching device Microcomputer pulse electrical degree measuring device
Microcomputer multi-functional transmission measuring device microcomputer disassembling device
(5) Management unit
Communication unit management unit dual management unit
5) Microprocessor protection device function
General technical requirements and indicators (working environment, power supply, technical parameters, device structure) and main functions of the microcomputer protection device (protection performance index, main protection function, protection principle, setting value and parameter setting, and external connection terminals and secondary Fig.) See related product specification.
7. 220/380V Low Voltage Distribution System Microcomputer Monitoring System
1) 220/380V Low Voltage Distribution System Features
(1) Wide range of applications. Nowadays, industrial and civilian electricity use is 220/380V except for mines, medical supplies, and dangerous goods stores. Therefore, the application range is very wide.
(2) Low-voltage power distribution systems are generally TN-S or TN-C-S systems. The TN-C system has three phase lines (A, B, C) and a neutral line (N). The N line is grounded at the neutral point of the transformer or repeatedly at the entrance of the building. The transmission line is four lines, the cable is four cores, there is no protective earth (PE), and one line is less. The outer shell of the device and the conductive ground of the metal are connected to the neutral line (N). This system is called the zero-connect system. The safety of the zero-connect system is poor, and the interference to the electronic equipment is large. The design specification has no longer been applied.
The TN-S system has three phase lines, a neutral line (N) and a protection ground (PE). The N line and the PE line are grounded at the neutral point of the transformer or repeatedly at the entrance line of the building. There are five power lines and five cores. After the neutral line (N) and the protective ground line (PE) are connected together at the grounding point, no connection can be made any more. Therefore, the neutral line (N) must also be insulated. After the neutral line (N) is led out, if insulation is not used to insulate the ground, or if it is connected to the protective ground after extraction, although five lines are used, it is also a TN-C system. This should be particularly noticeable. TN-S or TN-C-S systems have good security, and have little interference with electronic devices. They can share common ground lines (CPE). After equipotential bonding, they have better security and less interference. Therefore, the design specification stipulates that TN-S or TN-C-S systems are used except for special sites.
(3) 220/380V low-voltage power distribution system protection is still using low-voltage circuit breakers or fuses. So 220/380V is only monitored without protection. Monitoring includes current, voltage, power, frequency, power, power factor, temperature and other measurements (telemetry), switch operation status, accident tripping, alarm and accident prediction (overload, overtemperature, etc.) alarms (remote signaling) and electric switches Remote integration and opening operations (remote control) and other three contents (abbreviated as "three remotes") without protection.
(4) 220/380V low-voltage power distribution system The primary circuit is generally single busbar or single busbar section. Two or more transformers are single busbar subsections. There are several transformers divided into several sections. This is because the user substation transformer is generally Do not use parallel operation, this is to reduce the short-circuit current, reduce the short-circuit capacity, otherwise, the low-voltage circuit breaker's breaking capacity will increase.
(5) 220/380V low-voltage distribution system incoming line, bus coupler, large-load outgoing line and low-voltage connection line have larger capacity, and generally one circuit (1 circuit breaker) occupies a low-voltage cabinet. According to the size of the power supply load current, there are two outgoing lines (two circuit breakers installed), four outgoing lines (four circuit breakers installed), and five, six, eight, and ten outgoing lines in a low voltage switch cabinet, unlike the high voltage distribution. One breaker of the electric system occupies one switch cabinet. Therefore, the low-voltage monitoring unit must be used for one-way, two-way or multiple-way operation. The design must be designed according to the number of outlet loops of each low-voltage switch and the specifications of the low-voltage monitoring unit.
(6) In addition to manual operation of low-voltage circuit breakers, electric operation can also be selected. Large-capacity low-voltage circuit breakers generally have manual and electric operation. When designing, low-voltage monitoring units with remote control and low-capacity low-voltage circuit breakers should be used in design. Most of them are circuit breakers that are only manually operated so that the low-voltage monitoring unit can be remotely controlled. The outlet can be left unconnected, or a low-voltage monitoring unit without a remote control can be used.
2) Design of 220/380V Low Voltage Distribution System Microcomputer Monitoring System
(1) The 220/380V low voltage power distribution system microcomputer monitoring system firstly performs telemetry, remote signaling and remote control design according to the requirements of a system and user.
(2) Measurement circuit design
A. The secondary wiring of the measuring part is the same as the high voltage. The current loop is connected in series with the secondary loop of the voltage transformer, and the voltage loop is connected in parallel with the voltage measuring loop. Since the 220/380V low voltage distribution system has no voltage transformer, the voltage measurement can be directly connected to the 220/380V bus. As the voltage loop of the meter is generally not required to protect the fuse, the wiring in the cabinet should be as short as possible. It is best to add fuse protection to facilitate overhaul.
B electrical measurement can be used to have a power supply pulse output pulse meter, for the calculation of power and electrical power function of the low-voltage monitoring unit, only as an internal billing, pulse meter can no longer be selected.
C. The low-voltage monitoring unit with display function can be used to design the current and voltage meter. When selecting the low-voltage monitoring unit without the display function, the current or voltage meter should also be designed, and neither should be designed.
(3) Signal loop design
When designing, the low-voltage circuit breaker shall increase a pair of normally open contacts to the switch input terminals of the low voltage monitoring unit. If there is an accidental trip alarm output contact, it will be connected to the low voltage monitoring unit's accident notice terminal.
(4) Remote Control Circuit Design
The remote control design of the low-voltage monitoring system is relatively simple. The low-voltage circuit breaker operated by the electric motor has a pair of opening and closing buttons. As long as the low-voltage monitoring unit combines the output terminals of the sub-breaker and separates the opening and closing buttons, if necessary, one can be designed. The on-site and remote control operation switch prevents the remote control operation from causing an accident when the on-site maintenance switch is prevented.
(5) Power Supply and Communication Cable Design
Low-voltage monitoring unit power supply for the exchange of 220V power, power consumption is generally only a few watts, the design of its power from the terminal leads to a 220V/5A two pole low voltage circuit breaker, and then lead to the switchgear terminal, and then unified with KVV - The 3×1.0 cable is led to the small capacity outlet of the low-voltage cabinet. Add a UPS when needed.
Communication cable is generally not more than 200 meters away from KVV-3x1.0 general shielded control cable. When over 200 meters, shielded twisted pair cable (preferably jacketed type) or computer communication cable should be used.
8. Transformer Substation Integrated Automation System
1) System composition
The high voltage adopts the protection of the microcomputer, the low voltage uses the monitoring unit, and after connecting it with the computer through the communication cable, it can form a modernized substation management system—the integrated automation system of the substation.
2) Design content of integrated automation system for substations
A high voltage microcomputer protection unit (group screen or installed on the switchgear) type selection and secondary diagram design.
B low voltage microcomputer monitoring unit (installed on the switchgear) type selection and secondary diagram design.
C management computer (in the duty room, can be placed in power scheduling room when no one is on duty) selection.
D Analog dish (in duty or dispatch room) design.
E upper computer (with factory computer or power dispatching network) networking design.
F communication cable design (including management computer and host computer).
3) Management Computer
The management computer can be configured according to system requirements.
4) Analog disk
When the user requires an analog disk, the analog disk can be designed, the small system can be wall-mounted, and the large system can be floor-mounted. The size of the analog disk is determined based on the primary diagram of the power supply system and the area of ​​the duty room. The analog disk uses a dedicated control unit to direct its communication cable to the management computer. The analog disk also needs a 220V AC power supply and has a capacity of only a few tens of watts. It should be considered together with the management computer power supply when designing.
5) Main functions of integrated automation system in substations
The management computer of the integrated automation system of the substations and substations exchanges information with all the microcomputer protection and monitoring units installed on the site through communication cables. The management computer can send remote control commands and related parameter modifications downwards, and can receive telemetry, remote information and accident information transmitted from the microcomputer protection and monitoring unit at any time. The management computer can save the information through the processing of the information, record and screen display, and also analyze the operation of the system. Through remote communication, the accident can be discovered and dealt with at any time, and the time of power outage can be reduced. The remote control can be reasonable. The load is allocated to achieve optimal operation, which provides the necessary conditions for modern management.
The management computer software should be standardized, the operation should be simple and convenient, the man-machine interface is good, and the configuration is convenient. The user's use and secondary development are simple and easy to master.
5. DC screen of power distribution station
The GZDSW series of DC screens produced by Hefei Chunyan Electric Switch Co., Ltd. can be used in all substations listed above as the power source for operation, power station relay protection power supply, signal power supply and other purposes.
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