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Project Background Continuous power supply is an important guarantee for production capacity, quality and safety. When power outages occur, they are often accompanied by voltage sag. A voltage sag exceeding approximately 80 milliseconds will cause alarms and shutdowns of various high and low voltage motors, frequency converters and other equipment, causing the production system to stop production and seriously leading to production accidents. The currently adopted automatic switching scheme has slow switching during disturbances, which will cause load shutdown, posing safety hazards and risks of shutdown. In order to ensure the disturbance-free continuous power supply of the overall distribution network, it is necessary to add a disturbance-free fast-cutting system on the high-voltage side and an overall solution of adding anti-sway power modules on the load side. On the high-voltage distribution side, there are two 10kv lines between the 110kv substation and the 35kv substation. The distance between the two stations is about 300 meters. During normal operation, the 10kv high-voltage cabinet in the 35kv station is connected by 110kv substation 1 0kv power supply, 35kv in hot standby state, with two incoming lines, one main and one standby structure. The 10KV busbar is equipped with mixed loads such as various motors, frequency converters and transformers. Any power supply disturbance or voltage loss will affect the continuous operation of the load. On the low-voltage distribution side, low-voltage 400v equipment includes (3 450kw fans, 2 255Kw water pumps, 2 132kw water pumps), 2000kvA 4 low-voltage transformers, 2 2500KvA 2, and 1000kvA 1. For important motors, frequency converters and other equipment on the low-voltage load side, DCM621KH restarting anti-sway modules and MSpower need to be added The low-voltage ride-through device serves as a backup for the risk of fast switching. Plan Overview Through the overall understanding of the factory distribution network, a simplified diagram of the power distribution description is drawn, as shown in Figure 1 below.: Figure 1 The two 10KV incoming lines of the substation come from the 110KV substation and the 35KV substation. The 10KV bus carries mixed loads such as various motors and transformers. At the same time, it feeds multiple loops to the low-voltage distribution side and other substations. The 400V low-voltage buses carry mixed loads respectively. Fans, water pumps and other types of motors, frequency converters and soft starters are mixed loads. 2.1 Plan structure The 10KV substation is the 10KV main distribution side of the factory area, down to the 400V low-voltage distribution side and each substation. According to the current situation of on-site power distribution operation, combined with the feasibility of on-site construction and installation, and taking into account the transformer capacity problem of 35KV total drop, a set of anti-shock power solutions are now formulated. plan: The 10KV incoming line side is equipped with DCM-635G high-voltage non-disturbance fast cutting. On the 0.4kV load side, in order to ensure the continuity of the production process and according to actual needs, for some key process nodes, important equipment that strictly requires non-stop operation during the production process needs to be equipped with a low-voltage anti-shudder device. The contactor control motor circuit is equipped with a DCM621KH restart-type anti-slosh module, and the low-voltage inverter is equipped with a low-voltage ride-through device (non-critical frequency conversion is equipped with a DCM621KH anti-slosh module). In this plan, considering the capacity limitations of the 35kV incoming line and transformer, the on-site capacity is not enough to support the operation of all busbar equipment. Therefore, during the switching process, non-important loads are unloaded through the intelligent unloading outlet of the DCM635G device to ensure the normal operation of important loads. In addition, the low-voltage side circuit breaker on site has an instantaneous trip. When a brief power outage occurs during the high-voltage switching process, the low-voltage side circuit breaker trips due to tripping, causing the low-voltage busbar to lose power. It is recommended on site to remove the instantaneous voltage loss trip. The 400V low-voltage side can be equipped with a low-voltage standby automatic switch to realize power-off switching. System construction 3.1 10kV substation incoming line fast switching solution The 10KV substation power supply fast switching system, hereinafter referred to as the "10KV system", is completed by the DCM635G high voltage power supply non-disturbance fast switching device in conjunction with the on-site vacuum circuit breaker. Figure 2 below shows the construction of the solution. The illustration has been partially simplified. The power distribution structure is shown in the following figure: In Figure 2, the line from the "110KV substation" is referred to as incoming line one, and the line from the "35KV substation" is referred to as incoming line two. During normal operation, the entire section of the 10kV busbar is in the first incoming line, and the second incoming line is in a hot standby state. When the busbar loses voltage, it automatically and quickly cuts off the main incoming line, quickly closes the backup switch, and another normal power supply line takes the entire section of the 10kV busbar. The DCM635G non-disturbance fast-cut device collects key electrical parameters such as the amplitude, frequency and phase of the voltage and current of the two incoming lines and two bus sections, and intelligently identifies the current operating mode. The device has multiple starting methods such as manual switching, protection starting, voltage loss starting, false trip starting, etc., and has multiple closing strategies such as fast cutting, synchronization, residual voltage, and long delay to ensure that the spare incoming lines can be switched without disturbance to each other. The switching process is briefly described as follows:: Under normal working conditions, the first incoming line is under pressure, the second incoming line is under pressure, the first incoming line switch "1QF" is closed, the second incoming line switch "2QF" is open, and the non-disturbance quick-cut device enters the standby state after charging. When there is a voltage sag or power outage in the first incoming line, the non-disturbance fast switching system quickly trips the switch "1QF" and quickly closes the backup incoming line switch "2QF". The load is carried by the second incoming line to ensure the continuity of power supply and the load equipment does not stop during the switching process. When power is restored to the incoming line, manual switching returns to the initial state as needed. Because the 35kV system is not enough to drive all the equipment on the bus during the switching process, during the switching process, the unloading outlet function of the DCM-635G device is used to cut off non-important loads and complete the non-disturbing fast switching solution. The device is shown in Figure 3. Figure 33.2 Low-voltage load side anti-sway solution. The on-site motor protection device has an auxiliary restart function. When this function is enabled, the circuit needs to be modified, and there is uncertainty about the compatibility between the motor protection device and the on-site DCS. The restart-type anti-sway power module is a professional restart device for motors and frequency converters. It can be installed directly in parallel with the control loop on site without the need to modify the circuit. It is small in size and has a magnetic design that is easy to install on site. It is recommended to configure DCM621KH as a protection solution for key process nodes. 3.3 The anti-shock solution for straight-up motors is aimed at the straight-up motors that are very important on the low-voltage load side. In order to ensure the continuous operation of these important equipment under extreme conditions, an anti-shock module needs to be configured as a supplement to the quick-cut solution. The working principle of the module is to form a composite criterion by collecting the working power supply of the load, the contactor coil voltage and the control circuit voltage. After starting, it delays for 5 seconds to enter the anti-sway standby mode. When the contactor position signal changes, the internal supercapacitor system is automatically put in and the system starts timing. Within the set maximum power supply time, if the system automatically restores the power supply, it will start the motor after a restart delay and restore the normal working conditions before the power supply, thereby ensuring normal production. Important straight-up motor equipment is equipped with DCM621KH anti-sway module. The solution is as shown in Figure 4: The working process in Figure 4 is briefly described as follows: During normal operation, when the motor is started manually or remotely, the KM coil is energized and the KM contactor is closed. The DCM621KH detects the KM closed state and starts charging. After 5 seconds of charging, it enters the anti-sway standby mode. After the power shake occurs, the voltage drops, KM is actively released, and the motor stops. The internal supercapacitor of DCM621KH is automatically turned on to provide normal power supply to the anti-shock module. The system starts timing. If the system automatically restores power supply within the set maximum power-shock time (maximum 9 seconds), after the restart delay, the device RS relay is closed, automatically restarts the motor, and restores the normal working condition before the power-shock. 3.4 Frequency converter anti-shock solution For important frequency conversion equipment, there are two sets of solutions available according to different levels of continuous working requirements. If short-term shutdown is allowed, configure the DCM621KH anti-shock module. If shutdown is not allowed, configure the MSpower low-voltage ride-through device. Solution 1 is to configure the DCM621KH anti-sway module. Solution Figure 5 is as follows: The working process in Figure 5 is briefly described as follows: During normal operation, when the inverter is started manually or remotely, the 1KA1 coil is energized and the 1KA1 contactor is closed. DCM621KH detects the pull-in state of 1KA1 and starts charging. After 5 seconds of charging, it enters the anti-shaking standby mode. After power shaking occurs, the voltage drops, 1KA1 actively releases, and the inverter shuts down. DCM621K The AL relay of H opens and blocks the "inverter fault blocking signal" output. The internal supercapacitor of the DCM621KH is automatically put in to provide normal power supply to the anti-shock module. The system starts timing. If the system automatically restores power supply within the set maximum power-slosh time (maximum 9 seconds), the RE reset relay of the device closes to reset the inverter fault. After the restart delay, the device RS relay closes, automatically restarts the inverter, and restores the normal working conditions before the power slosh. Option two is to configure the MSpower low voltage ride-through device. For inverters installed on site, in order to ensure that they do not shut down during power outages, MSpower low-voltage ride-through devices need to be configured. u MSpower device structure: The MSpower device consists of a host computer, a touch screen display unit, a supercapacitor box and a DC power distribution system. The host and touch display unit are used to display AC power supply, DC output current, operating conditions, historical records, system settings, fault information, low voltage ride-through information with time stamps, and successful ride-through statistics. At the same time, they can realize interlocking with external devices and real-time self-test of the entire device, as shown in Figure 6. Figure 6 The voltage sag control host is the core unit of the entire device, completing supercapacitor charging management, grid monitoring, system self-test, etc. After rectifying the three-phase AC, the DC energy is precharged to DC 520V±5% through isolation transformation. When the power consumption of the plant fluctuates within ±10%, the host will not supply power to the DC bus of the coal feeder frequency converter due to voltage sag. ； When the three-phase AC drops below 90% (360V), the voltage sag host automatically outputs instantly to ensure that the DC bus returns to the normal operating range. The supercapacitor box uses imported super farad capacitors. The supercapacitor is charged and managed through the host to complete various charging modes such as constant current, constant voltage, and trickle current. It also has an automatic temperature management system and a protective voltage equalization system. The DC output circuit mainly consists of branded DC circuit breakers, discharge detection, etc. Each DC power distribution circuit corresponds to one frequency converter. u Working principle: The schematic diagram of the device structure is as shown in Figure 7: Figure 7 Three-phase AC power enters the three-phase rectifier circuit through circuit breaker QF1. The pulsating DC precharges C1 through the current limiting resistor. After precharging, the capacitor C1 is fully charged through the DC contactor KM1 bypassing the current limiting resistor. Inductor L1, Q1 and Q2 form a BOOST type boost circuit, which pumps the DC charge on C1 to a higher voltage to charge C2, and charges capacitor C3 through the precharged current limiting resistor. It passes through the thyristor and diode anti-reverse circuit to the DC contactor and then passes through the circuit breaker and fuse to the DC bus of the frequency converter. At normal operating voltage, the inverter maintains normal operation of the inverter through the internal bridge rectified DC power supply, and the BOOST boost circuit is in standby state. ； When the grid voltage drops instantaneously and reaches the set value (default 80%, adjustable), the BOOST circuit quickly goes into operation and outputs a stable DC voltage to support the voltage stability of the DC bus of the inverter, thereby maintaining the speed and torque of the variable frequency motor. After the grid voltage recovers (default is 90%, adjustable), the BOOST boost circuit automatically exits, and the inverter continues its internal rectification and power supply operation. This low-voltage ride-through device operates in bypass mode. The AC power supply line of the original frequency converter does not need to be adjusted, and there is no need to make new settings for the frequency converter. It only needs to be installed on-site next to the original frequency conversion control cabinet. A DC screen can be introduced on-site to directly supply power to the low-voltage ride-through device. Functional features and parameters 4.1 Disturbance-free fast switching system 4.1.1 Basic functions ◆ The device is suitable for double incoming line structure ◆ It has various starting modes such as manual start, protection start, low-voltage start, false trip start, no-flow start, reverse power start and abnormal frequency start ◆ The device has the functions of normal switching, accident switching, and non-working condition switching (loss of voltage, switch mis-trip) ◆ The device has three switch switching sequence options of parallel, series and simultaneous ◆ The device has priority Fast, simultaneous capture, residual voltage, long delay switching 4.1.2 auxiliary functions ◆ Intelligent switching lock identification inside and outside the zone ◆ Backup power loss ◆ Abnormal switch lock ◆ Closing circuit timing measurement ◆ Intelligent fault recording ◆Holographic black box record ◆Device self-test fault alarm ◆PT disconnection ◆Bus coupler switch current protection (bus coupler mode) ◆Intelligent unloading outlet (optional) ◆Remote call and modification of fixed value 4.1.3 Resources and configuration ◆Analog quantity: Eight-channel voltage input (two-channel incoming line voltage + three-channel busbar section 1 voltage + three-channel busbar section two voltage) nine-channel current input (six-channel incoming line current + three-channel bus current) ◆Binary input: The device is fully equipped with 30 channels of input and output.: The device is fully equipped with 22 relay outputs 4.1.4 Communication functions ◆Two standard RS485 multi-machine communication ports ◆Two industrial Ethernet ports ◆Supports single network and dual network communication, and can fully realize network redundancy and mutual backup ◆One printing interface, compatible with a variety of printers ◆IEC-60 870-5-103 (serial communication mode), IEC-60870-5-103 (industrial Ethernet communication mode), MODBUS-RTU, MODBUS-TCP standard communication protocol 4.1.5 GPS time synchronization function ◆The device supports 1PPS and IRIG-B code time synchronization modes through RS485 differential level, the error is less than 1ms, and it also supports software background time synchronization. 4.1.6 Features of the device ◆ Adopts a dual-core 32-bit DSP microprocessor, with independent fast-cutting core and human-machine interface core ◆ Real-time multi-tasking operating system and C++ programming technology, enabling online programming ◆ Accurate statistics of switch closing time, automatically adapting to switch aging and switch replacement ◆ Real-time system self-test, system working power supply, AD status, and memory status real-time self-test to ensure stability and reliability ◆ Anti-interference Design, highest EMC electromagnetic compatibility level test, software and hardware composite locking architecture ◆ Large screen dual display (LCD Chinese display and LED display), convenient for inspection by operators ◆ Good hardware interchangeability, convenient for user maintenance and reducing the number of spare parts ◆ Using 6U, 19/3-inch standard chassis, back-plug structure, can be installed on the switch cabinet or centralized screen assembly 4.1.7 Rated parameters ◆ Device power supply: AC/DC 86～265V◆Operating voltage: DC 220V, DC 110V or AC220V (allowable deviation +15%, -20%) ◆AC voltage: 100V or 380V (please specify when ordering) ◆AC current: 5A or 1A (please specify when ordering) ◆Applicable frequency: 50Hz4.1.8 power consumption ◆DC circuit : <10W (during normal operation) ； <15W (during operation). ◆AC voltage circuit : <0.5VA/phase◆AC current loop : <1VA/phase (In=5A) ； <0.5VA/phase (In=1A). 4.1.9 Overload capability ◆AC voltage: 1.2 times rated voltage continuous operation ◆Protective current: Continuous operation at 2 times the rated current, 10 times the rated current, allows 10 s, 40 times the rated current, allows 1 s4.1.10 Measurement range and accuracy ◆Voltage component : 1% Un～120% Un◆Current element : 0.05In～20In◆frequency : 30.00Hz～65.00Hz◆Time element : 0.00S～100.00S◆Voltage and current accuracy : Level 0.5◆Frequency accuracy : 0.02Hz◆Angle accuracy : 0.2 degrees◆SOE resolution : ≤2ms◆Closing time measurement : ≤2ms◆GPS timing : ≤1ms4.1.11 Setting value accuracy ◆ Current and voltage setting : ≤±2.5% setting value ◆frequency setting : ≤±0.02Hz◆Angle fixed value : Angle difference setting error: ±0.2°◆Switch minimum power outage time : <11 ms+switching time+user setting delay. 4.1.12 Outlet contact capacity ◆The tripping and closing outlet can be connected to AC 250V, 5A for a long time. ◆The signal outlet can be connected to AC 250V, 5A for a long time. 4.1.13 Electromagnetic compatibility ◆Fast transient interference test complies with the regulations of GB/T 14598.10 ； ◆The electrostatic discharge test complies with the regulations of GB/T 14598.14 ； ◆The pulse group interference test complies with the regulations of GB/T 14598.13 ； ◆The radiated electromagnetic field interference test complies with the regulations of GB/T 14598.9 ； ◆The power frequency magnetic field immunity test complies with the regulations of GB/T 17626.8 ； ◆The conducted disturbance immunity test induced by radio frequency fields complies with the regulations of GB/T 17626.6 ； ◆The pulse magnetic field immunity test complies with the regulations of GB/T 17626.9 ； 4.1.14 Insulation withstand voltage ◆The insulation test complies with the regulations of GB/T14598.3-93 6.0 ； ◆The impulse voltage test complies with the regulations of GB/T14598.3-93 8.0. 4.1.15 Environmental conditions◆Operating temperature: -20℃～+55℃. ◆storage temperature: -25℃～+70℃, relative humidity not more than 80%, rainproof and snowproof indoors where the surrounding air does not contain acid, alkaline or other corrosive and explosive gases ； If no excitation is applied at the limit value, the device will not undergo irreversible changes, and the device should be able to operate normally after the temperature recovers. ◆relative humidity: The monthly average maximum relative humidity of the wettest month is not greater than 90%, and the monthly average minimum temperature of the month is not lower than 25°C and there is no condensation on the surface. When the maximum temperature is +40°C, the average maximum humidity does not exceed 50%. ◆atmospheric pressure: 80kPa～110kPa (relative altitude below 2km). 4.1.16 Fault wave recording ◆Record 2 cycles before switching start, up to 98 cycles after start, and up to 32 sets of wave recording data. The recording data format meets the COMTRADE99 standard. 4.2 DCM621KH restart motor anti-sway meter 4.2.1 Basic parameters u System power consumption: 1Wu installation method: Magnetic typeu Dimensions: 64mm * 47mm * 96mm (width * high * Deep) u product net weight: Approximately 300 grams u Applicable voltage : AC220V (customizable) u Starting node capacity: Normally open, 5A 440Vac/300Vdcu RUN signal capacity: Normally open, timeout return, 5A 250Vac/30Vdcu maximum power consumption time: 0-9s adjustable, step 1s, module exits at 0. u restart delay: 0-1S continuously adjustable, step 0.1S. u Applicable circuit: Direct start, frequency converter, soft start 4.2.2 Functional features u The starting motor is in automatic standby, and it automatically discharges when it is manually stopped. ； u Magnetic installation, reliable and flexible ； u Plug-in terminals for easy maintenance ； u Pulse starting, energy saving and reliable ； u The power-down time is up to 10S and is easy to modify ； u The restart delay can be modified, which is beneficial to multi-motor environments in batches. ； u The voltage fluctuation does not cause the contactor to release and will not affect the anti-sway module. 4.3 MSpower low voltage ride-through device 4.3.1 Basic parameter name Basic parameter model MSpower-C Rated power 10-1000kW Input voltage level AC 80V~400V AC input rated frequency 50Hz±2 Hz DC output voltage DC 490V±5% Voltage drop support range 20%~90%Ue Working time 0-30s time-adjustable electromagnetic interference level conforms to IEC standard DC power supply switching time ≤ 200 microseconds, semiconductor conduction time noise ≤ 60dB Action interlock with frequency converter operation/fault interlock with uninterruptible power supply Comprehensive efficiency ≥ 99% Alarm output Various types of alarm output short-circuit protection, overload, etc. There are heat dissipation methods Intelligent air-cooling system in/out line form, bottom in and bottom out Figure 84.3.2 Functional features u Modular design, convenient for installation, maintenance and debugging ； u Fast switching, when the grid voltage drops by 80%, it can still provide 30s delay support ； u External interlock control can be expanded to improve system security ； u The system’s independent module self-test enables long-term maintenance-free operation. ； u Large industrial touch screen display, intuitive and detailed system operating conditions ； u Communication function supports RS485 and Ethernet, easily realizing DCS system interconnection ； Detailed description of the functions of the quick-cut system 5.1 The wiring terminals of the switching function are shown in the figure below. The system consists of two incoming lines. During normal operation, the first incoming line supplies power to the entire busbar, and the second incoming line provides backup power supply. Starting mode: Manual, protection, voltage loss, false trip, no current, reverse power, frequency voltage starting switching process: Jump 1QF to 2QF, jump 2QF to 1QF. Figure 95.2 Auxiliary function u The intelligent closing timing device is equipped with a high-precision switch closing timing function, which can accurately measure the time from when the device sends the closing command to receiving the switch closing signal, including the switch closing time and the electrical time on the closing circuit. If no switch closure is detected within 5 seconds, the recorded data is invalid. In the incoming line mode, measure the closing time of the incoming line first low switch and the incoming line second low switch. ； In the bus tie mode, measure the closing time of the incoming line first low switch, the incoming line second low switch and the bus tie switch, and each switch records the latest six time values. u Locking function: The following locking functions are self-returning locking: ●The switch position is abnormally locked, the incoming line current is greater than the no-current setting value, and the corresponding switch is tripped, and the alarm is delayed for 10 seconds ●Backup power loss lockout, the incoming line current is greater than the no-flow setting value, the backup power supply is less than the "backup loss of voltage voltage setting value" and the "backup power loss lockout" is turned on, and the device is locked. ●The function of blocking is not enabled, and the "switching on and off" function is not enabled. ； Start mode is not enabled at all ； Switching mode is not input at all ； When any of the above conditions are met, the device is locked. ●The outlet is locked. During the test, the signal locking device is used. When there is a signal input to terminal 332, the device exit is locked and the signal is released and disappears. ●PT disconnection latch, "PT disconnection switch" is enabled, when the bus PT is disconnected, through the "voltage loss detection incoming line no voltage" control word selection, detect the incoming line and bus no voltage or detect the incoming line no flow and bus no voltage latch switching, or through the bus negative sequence voltage latch switching, fault release latch return. ●Busbar PT inspection lock is used for manual locking device during maintenance. When there is a signal input at terminal 337, the device outlet is locked, and the signal is released and the lock disappears. The following latches are manual reset latches: ●Protection lockout 1 and protection lockout 2. When the protection lockout is installed on this side and is connected, a protection action signal is generated to switch the lockout. When the signal is released, manual reset is required to return the lockout. ●Overcurrent switching and blocking, when there is no protection blocking on the local side, when the busbar and outlet faults occur, it is used to identify the fault blocking switching in the area. When the current is in the positive direction (flowing from the incoming line to the bus) and the current value is greater than the "directional overcurrent blocking value", the device blocks and switches and alarms (this function must be connected to the three-phase current of the incoming line). ●Switching latching, when the 332 terminal has a switching latching signal, the device is latched. When the signal is released, manual reset is required, and the latching returns. When any of the above situations occurs, the device is locked, the panel "lock" light is illuminated, and the exits 215-216 are closed. u Alarm function ●Self-check alarm, real-time self-check when the device is running. When the self-check fails, a device fault signal is sent (209, 210 is closed), and the switching and protection functions are blocked at the same time. Self-check faults include: RAM, EPROM, exit failure, setting error and power failure. When the following conditions are detected, an alarm signal is issued (211, 212 closed): ●Reverse power alarm, if any of the three-phase incoming current is greater than 0.1A and the power is reversed, after a fixed delay of 10ms, the device will alarm and record. (Only an alarm will be issued, and switching will not be started or blocked. At this time, the bus voltage is lower than the reverse power voltage threshold before switching can be started). This function is mainly used to check on-site wiring and monitor power grid voltage fluctuations, and provide accident analysis materials. ●Voltage loss alarm, when the working bus voltage is detected to be lower than the voltage set value, the device will alarm and record after a fixed delay of 20ms. (Only alarm, not starting or blocking switching). This function is mainly used to monitor power grid voltage fluctuations and provide accident analysis materials. ●Internal frequency measurement failure (voltage greater than 15%, frequency less than 30Hz or greater than 65Hz, fixed delay 10s alarm) When any of the above conditions occurs, the device alarms, lights up the "alarm" light on the panel, and closes exits 211-212. Automatically returns when the alarm condition is cleared, no need to reset. u Other functions ● Post-start acceleration function During the switching process, if a certain incoming line is closed, a pair of post-acceleration contacts will be output at the same time to start the post-acceleration function of the incoming line. This node will return after the switching is completed. ●The power disappearing device of the quick-cut device provides a pair of normally open and normally closed nodes for the power disappearing signal. If the power of the device disappears, the 207-208 normally closed nodes are opened and the 207-206 normally open nodes are closed. After the power is restored, the nodes return. ●The decoupling function is to prevent two power supplies from running in parallel for a long time. During the "decoupling delay" time during the switching process, the switch that should be closed is closed but the switch that should be tripped is not tripped. The quick-cut device will perform the decoupling function and trip the switch that was just closed. ●The low-voltage load shedding function (optional) is limited by the capacity of the transformer. When the bus coupler is running (the bus coupler is in the closed position), the load shedding function is started based on voltage slip, undervoltage and overcurrent, and the non-important load is tripped to ensure the continuous and reliable operation of the system. 5.3 Fast switching process 5.3.1 Switching flow diagram DCM635 power supply non-disturbance fast switching device provides seven starting methods. Parallel, simultaneous and series connection are supported during manual start. Misjumping supports series connection, and the other five starting methods support series connection and simultaneous switching. The parallel switching mode only has a fast switching implementation mode, while series and simultaneous support support four switching implementation modes: fast, simultaneous capture, residual voltage and long delay. Figure 105.3.2 Starting mode DCM635G power supply disturbance-free fast switching device provides seven modes in total: manual starting, protection starting, voltage loss starting, reverse power starting, no flow starting, frequency voltage starting and false jump starting. u Manual start. The manual starting method is mainly used for system shutdown, incoming line maintenance and incoming line recovery after a fault. The manual button triggers the switching function through the input amount. The manual start of the device sets specific switching logic for bus coupler operation mode and incoming line operation mode. In the incoming line mode, manual start can realize mutual switching between incoming line 1 and incoming line 2. In the bus coupler mode, use "Manual Start One" to start the switching between the 1 incoming line and the bus coupler, and "Manual Start Two" to start the switching between the 2 incoming line and the bus coupler. u Protection starts. Introduce the upper-level fast main protection contact on the power supply side into the quick-cut device to start switching. After the system is charged, it runs normally. Once the upper-level main protection action signal is detected, the quick-cut device immediately starts switching, disconnects the fault line, and puts in the backup power supply u to start by accidental jump. When the system is running normally after charging, if the switch in the closed position suddenly trips and the incoming line current on that side is less than the no-current value, the device will start and switch by mistake, and close the power supply on the other side to ensure the bus power supply. u Start without pressure. The device provides two criteria for the user to choose: voltage loss detection incoming line voltage and voltage loss detection incoming line current, and the selection is made through the "no voltage detection incoming line voltage" control word. When the "voltage loss detection incoming line no voltage" control word is 1, if the device detects that the bus three-phase voltage and the incoming line voltage are both lower than the voltage loss starting setting value, the set delay device will start the switching function. When the "Loss of voltage detection incoming line no voltage" control word is 0, when it is detected that the three-phase voltage of the bus is lower than the loss of voltage starting setting value and there is no flow in the incoming line, the setting delay device starts the switching function. This starting mode can be turned off through the control word in the setting. The voltage loss starting logic is as follows:: u Start without flow. When the device detects that the incoming line current changes from current (greater than the no-current starting setting value) to no current (less than the no-current starting setting value), and the bus frequency is less than the no-current starting frequency setting value, the device delays the start switching function through setting. The no-flow starting method is mainly used in working conditions where the protection on the side of the incoming line cannot be connected to the device. The logic is as follows: u Start with reverse power. When there is no incoming line fast protection contact starting device switching, this starting criterion can be used to achieve fast switching under fault conditions. The logic is as follows: u Frequent voltage start. Frequency-voltage starting is mainly used when the incoming line current is very small. After the incoming line power supply disappears for various reasons, the workload runs on an isolated grid, and the bus frequency will deviate from the industrial frequency. At this time, no-flow starting and reverse power starting are not suitable. The logic diagram is as follows.