38results about How to "Reduce switching frequency" patented technology

The invention relates to the technical field of MMC sub-module balance control, and discloses a capacitor voltage balance control method and system for an MMC sub-module, and an MMC, and the method comprises the steps: judging whether a bridge arm is in a near-zero current risk region or not according to the direction of the current of the bridge arm in each valve control period; if the bridge arm is not in the near-zero current risk area, judging whether the bridge arm is in a modulating wave extreme value risk area or not according to the bridge arm modulation voltage instruction; if the bridge arm is in a near-zero current risk area or a modulating wave extreme value risk area, a first switching strategy is adopted; and if the bridge arm is not in the modulating wave extreme value risk area, a second switching strategy is adopted. According to the invention, the switching frequency is effectively reduced and the narrow pulse phenomenon of the sub-module is eliminated through the judgment of the frequent switching risk area and the corresponding switching strategy, meanwhile, the module alternation probability is effectively reduced through the sorting switching strategy based on the dynamic additional factor, and the fluctuation range of the module voltage is limited within the required range, so that the switching efficiency is improved. And the operation safety and stability of the MMC are ensured.

The invention provides a dust collection assembly, cleaning equipment and a cleaning system, the dust collection assembly is provided with a dust inlet, a dust extraction opening and a dust collection cavity communicating the dust inlet with the dust extraction opening, the dust collection assembly comprises a bottom wall and a side wall, the side wall extends in the circumferential direction of the bottom wall, the side wall and the bottom wall are connected, the dust collection cavity is defined by the side wall and the bottom wall, and the dust extraction opening is formed in the side wall. The design of a dust extraction opening and an accessory structure thereof on the bottom wall is omitted, the bottom area near the bottom wall is utilized as the volume of the dust collection cavity, and the utilization rate of the dust collection space is increased. The side wall is provided with sufficient available space, the dust extraction openings can be designed without being limited to the structural complexity and the number of the dust extraction openings, the structures and the number of the dust extraction openings can be variously selected and set according to actual requirements, and meanwhile, the sufficient available space is beneficial to improving the switching convenience of the opening and closing states of the dust extraction openings; and the dust extraction efficiency of the cleaning base station from the dust extraction opening is improved.

According to the control method and control system of the frequency conversion device and the air conditioner, under the condition that the temperature data exceeds the first temperature threshold value, the dead zone time and / or the minimum opening time of the frequency conversion device are / is dynamically adjusted, effective control over the temperature of the frequency conversion device is achieved, and the service life of the frequency conversion device is prolonged. The problem that the temperature of the frequency conversion device is not properly controlled in the prior art is solved. Specifically, the method can effectively reduce the switching frequency and continuous turn-on duration of switching devices such as an IGBT (Insulated Gate Bipolar Transistor) and the like in a mode of timely increasing the dead time and the minimum turn-on time, thereby reducing the calorific value of the switching devices, reducing the turn-on and turn-off loss, and avoiding performance reduction or device damage caused by overhigh temperature. Meanwhile, the control mode does not change the carrier frequency, so that the response speed and the control precision of the system are not influenced, the stable output power of the frequency conversion device is ensured under severe working conditions, and the reliability and the service life of equipment are improved.

The present invention discloses a parallel structure high-efficiency envelope tracking power supply and a control method thereof, comprising a parallel switching converter and a linear amplifier, wherein the switching converter and the linear amplifier respectively work in a current source form and a voltage source form; the output current of the switching converter fits the load current in a triangular wave form, and the linear amplifier is used to compensate for the difference current between the load current and the output current of the switching converter. The present invention can reduce the voltage borne by the power tube during operation, reduce the switching frequency of the CSC, greatly reduce the loss of the VLA, and significantly improve the efficiency of the parallel structure envelope tracking power supply.

The present invention provides a zero-crossing resonance ZVS control circuit of a four-switch buck-boost converter, which enables some switches to work in a ZCS state to reduce the loss of circuit switch components. i >V o When the inductor current changes from negative to positive, Q4 is turned off, so that Q4 is turned off with zero current; when V i <V o When the inductor current changes from positive to negative, Q1 is turned off, so that Q1 is turned off with zero current. The present invention uses an inductor current zero-crossing control method for a four-switch buck-boost converter, breaking the limitation of the ZVS current. Under the same output current condition, the effective value of the inductor current can be reduced, and the circuit loss can be reduced; and a lower switching frequency can be obtained when the same power is output, which is beneficial to reducing the loss of the switching device; at the same time, the corresponding switching device can be turned off at the current zero-crossing point, which is beneficial to reducing the switching loss and voltage stress of the switching device, and further improving the conversion efficiency of the circuit.

The invention belongs to the technical field of motor control, and discloses a motor model prediction control method based on asymmetric hybrid vector pulse width modulation. Six sectors of a space voltage vector are divided into odd number sectors and even number sectors. In a singular sector, only a zero vector and a corresponding non-zero effective vector are adopted to perform two-section asymmetric synthesis, so that only one switching state change occurs in one period; in an even number sector, a non-zero effective vector in the sector, a non-zero effective vector in an adjacent odd number sector screened by a cost function and a zero vector are adopted to carry out three-section type asymmetric synthesis, and unnecessary switching actions are avoided while the current tracking performance is ensured. By means of the method, targeted control over the switching times is achieved in different sectors, and the average switching frequency is reduced. In the even-number sectors, optimization is carried out between the non-zero effective vectors of the adjacent odd-number sectors, the current prediction error is further optimized under the condition that the switching frequency is not obviously increased, and the current performance is ensured.

The invention discloses a two-step model-free predictive control method and device for a three-level inverter in the technical field of power electronics. The method comprises the following steps: constructing an over-limit equation of the three-level inverter through Clark transformation; estimating the over-confinement equation based on a neural network, and constructing a discrete time model about an approximate Euler formula; performing two-step prediction based on the time model, and constructing an evaluation function; traversing the candidate quantity of the alternating current side voltage according to the evaluation function, and taking the switching state corresponding to the candidate quantity with the minimum value of the evaluation function as a control signal of the three-level inverter at the next moment; according to the method, the neural network predictor is adopted, the method does not depend on an accurate mathematical model and system parameters, the accuracy of current tracking is effectively improved, and the robustness of the system is enhanced. The optimization range is expanded to two control periods by adopting a two-step prediction structure, and the probability of applying the same voltage vector in the continuous control period is improved, so that the switching frequency is remarkably reduced.

The present invention discloses a midpoint potential control method of an NPC four-bridge arm inverter with low switching frequency, comprising the following steps: S1, obtaining a three-phase reference voltage, comparing the three-phase reference voltage with a neutral bridge arm reference voltage, and obtaining the maximum and minimum values ​​of the four reference voltages; S2, establishing two positron modulation waves of each bridge arm, deriving a general expression of the two positron modulation waves of each bridge arm, and calculating the optimal bias voltage and the two optimal positron modulation waves of each bridge arm; S3, calculating the modulation wave adjustment value of the midpoint current adjustable bridge arm; S4, obtaining the adjusted two positron modulation waves of each bridge arm according to the two optimal positron modulation waves of each bridge arm and the modulation wave adjustment value; S5, comparing with a single carrier to generate a pulse signal for controlling the on and off of a power switch tube. The present invention adopts the above-mentioned midpoint potential control method, and has a lower switching frequency and similar midpoint potential low-frequency oscillation control capability.

The embodiment of the invention provides a multi-target rendering method, and the method comprises the steps: obtaining a plurality of target objects corresponding to a target video frame, and each target object is associated with identification information; according to the identification information of each target object, obtaining a measurement size and on-screen information of each target object; determining a rendering size and a rendering area of each target object according to the measurement size of each target object and a preset target canvas; according to the rendering size and the rendering area of each target object, drawing the plurality of target objects into the target canvas to obtain a target texture; and according to the target texture and the on-screen information of each target object, rendering each target object to the target video frame. According to the technical scheme provided by the embodiment of the invention, the rendering time consumption and the frame dropping frequency can be greatly reduced, and the batch rendering fluency of the multiple target objects is improved.

The application relates to a frequency multiplication circuit and a frequency multiplication device. The frequency multiplication circuit comprises a first high-voltage switch circuit, a second high-voltage switch circuit and a delay circuit. The application replaces the operational amplifier in the traditional frequency multiplication circuit with the first high-voltage switch circuit, the second high-voltage switch circuit and the delay circuit, can generate a frequency multiplication signal based on a reference pulse signal and an input voltage, and can adapt to a high-voltage environment. Meanwhile, since the frequency multiplication signal is obtained by synthesizing the pulse signals output by the first high-voltage switch circuit and each second high-voltage switch circuit, a single first high-voltage switch circuit or second high-voltage switch circuit only needs to output a pulse in the period of a reference pulse signal, thereby avoiding the problem that a single high-voltage switch circuit cannot directly output a high-frequency signal due to a low switching rate of the single high-voltage switch circuit.

The invention belongs to the field of motor control, and particularly discloses a control method for driving a low-inductance high-speed motor by a high-voltage power supply. The software part comprises a commutation module, a bidirectional DC / DC conversion module, a brake module, a rotating speed PI controller and a voltage PI controller, the hardware part is provided with a Hall sensor and a low-inductance high-speed brushless direct current motor, and the commutation module realizes six-step commutation of the brushless direct current motor; the bidirectional DC / DC conversion module is used for realizing a step-down speed regulation function when the motor is driven, and realizing a step-up energy backflow function when the motor reversely generates power; the brake module realizes the functions of voltage limiting and energy storage when the motor reversely generates power; the rotating speed PI controller compares the actual motor rotating speed with a rotating speed reference value and generates a direct-current voltage reference value; the voltage PI controller compares the measured bus DC voltage with a voltage reference value, generates a required duty ratio through modulation, and outputs the duty ratio to the DC / DC module; and the Hall sensor realizes acquisition and feedback of the rotor position.

The utility model provides a novel series topology photovoltaic converter. The photovoltaic converter comprises a common mode inductor, a BOOST circuit and an inverter circuit which are connected in sequence on a direct current bus between a photovoltaic direct current power supply and a three-phase alternating current power supply, because the common mode inductor adopts a reverse winding method that two coils are wound on the same iron core, and the number of turns and the phase are the same, when normal current in a circuit flows through the common mode inductor, the current generates reverse magnetic fields in the inductance coils wound in the same phase so as to cancel out each other, so that the common mode inductor is formed. At the moment, the current is mainly influenced by coil resistance and a small amount of damping caused by leakage inductance; when a common-mode current flows through the coil, due to the homodirectivity of the common-mode current, a homodromous magnetic field can be generated in the coil to increase the inductive reactance of the coil, so that the coil shows high impedance and generates a relatively strong damping effect, the common-mode current is attenuated, the purpose of filtering is achieved, the filtering capability of a photovoltaic current can be greatly enhanced, and a leakage current can be greatly inhibited.

This application provides a general-purpose liquid packaging film, comprising a three-layer co-extruded layer formed by three-layer co-extrusion blown film. The three-layer co-extruded layer includes an inner layer, a middle layer, and an outer layer. The inner layer comprises LLDPE-FG5224, MVLDPE-SP0540, LDPE-2426K, LLDPE-FG5190, and PPA-A1058. The middle layer comprises MLLDPE-1327CA, LLDPE-2056AC, LDPE-2426K, and PPA-A1058. The outer layer comprises LDPE-2426N, LLDPE-7042, MLLDPE-1327CA, and PPA-A1058. This application also provides a method for preparing the general-purpose liquid packaging film. The film produced by the formulation and process provided in this application exhibits physical properties such as tensile strength, elongation at break, and coefficient of friction that are adaptable to the requirements of packaging liquids with different contents, thereby reducing the frequency of formulation changes during production and consequently reducing production costs.

This utility model relates to a dual power supply switching circuit and a dual power supply circuit, belonging to the field of high-voltage switch control technology. The switching circuit includes: a coil of a first contactor and a normally closed contact of a second contactor connected in series to the main power supply line between the main power supply and the electrical load; a normally open contact of the first contactor connected in series on the main power supply line; a coil of the second contactor and a normally open contact of a time relay connected in series to the backup power supply line between the backup power supply and the electrical load; a normally open contact of the second contactor connected in series on the backup power supply line; a coil of an undervoltage relay connected to the main power supply line; and a normally closed contact of the undervoltage relay and a coil of the time relay connected in series to the backup power supply line. This utility model, by using an undervoltage relay and a time relay, reduces frequent switching between main and backup power supplies, and has a simple circuit structure, low cost, and is easy to maintain.

The application discloses a PFC-LLC resonant switching power supply, which comprises a PFC circuit and an LLC circuit, an input end of the PFC circuit is connected with an AC input interface, an output end of the PFC circuit is connected with an input end of the LLC circuit through a high-voltage bus, an output end of the LLC circuit is connected with a DC output interface, and the PFC-LLC resonant switching power supply further comprises a bus voltage sampling circuit, a fault detection circuit, a first enabling control circuit and a second enabling control circuit, an input end of the first enabling control circuit is connected with an output end of the fault detection circuit, an output end of the first enabling control circuit is connected with a voltage sampling end of a PFC control unit of the PFC circuit, a first input end of the second enabling control circuit is connected with the output end of the fault detection circuit, an output end of the second enabling control circuit is connected with a voltage feedback input end of an LLC control unit of the LLC circuit, an input end of the bus voltage sampling circuit is connected with the input end of the LLC circuit, and an output end of the bus voltage sampling circuit is connected with the voltage feedback input end of the LLC control unit.

The application provides a communication frequency selection method and system based on multi-factor heuristic adaptive scoring, which first initializes a candidate frequency point set and related parameters, and then collects channel state parameters of each frequency point in each decision time slot. After normalization processing, the collected parameters enter the EWMA history smoothing link to obtain more stable frequency point evaluation results. According to the current communication environment, corresponding weight configuration is selected, and the comprehensive heuristic score of each selected frequency point is calculated. If the SINR of the current working frequency point is lower than the set threshold or the packet loss rate is higher than the set threshold, the fast reselection mechanism is triggered to directly select the frequency point with the better score; if the fast reselection mechanism is not triggered, the regular hysteresis judgment is entered, and only when the selected frequency point has sufficient score advantage over the current frequency point and overcomes the switching cost, the frequency switching is performed, thereby improving the stability of the communication frequency selection.

The invention relates to a priority setting method and device for a virtual router group and a storage medium, and the method comprises the steps: detecting the fault state occurrence frequency of target router equipment in a target virtual router group, and determining the fault state occurrence frequency of the target router equipment in the target virtual router group; when the fault state occurrence frequency of the target router equipment meets a preset priority adjustment condition, reducing the priority of the target router equipment in the target virtual router group according to a preset reduction proportion; wherein the target virtual router group comprises at least two router devices; and monitoring the available state of the target router equipment, and when it is monitored that the available state of the target router equipment meets a preset stable condition, recovering the priority of the target router equipment to a preset priority. According to the method, the priority of the fault router equipment can be lowered, so that the main and standby switching frequency is reduced, the flow forwarding stability is finally improved, and data packet loss is reduced.

The application discloses a synchronous link data transmission method, a communication device and a storage medium. The method is used for synchronous link data transmission between a first device and a second device. The synchronous link has a reserved transmission window set at a preset interval. The first device generates a first service data block corresponding to the reserved transmission window in time sequence. The method is executed by the first device. The method comprises the following steps: in response to the fact that data transmission associated with a previous first service data block has been completed in a current transmission window, determining whether the current transmission window has sufficient remaining time; and in response to the fact that the current transmission window has sufficient remaining time, performing data transmission associated with a first service data block to be currently transmitted with the second device. The application can optimize the synchronous link of the pre-allocated time slice, improve the fragmentation problem of the time slice available for other links, reduce the link switching frequency, and improve the scheduling efficiency.

The present application relates to a kind of renewable hydrogen sulfide removing agent and its preparation method and application, the renewable hydrogen sulfide removing agent with silica alumina gel as carrier, by loading aluminium hydroxide colloidal solution to silica alumina gel carrier, continue water vapor aging makes aluminium gel and carrier secondary combination, thereby obtains the hydrogen sulfide removing agent with more concentrated pore size distribution, active adsorption site is more abundant.The removing agent is suitable for the removal of hydrogen sulfide in hydrocarbon organic medium, the use condition range is that hydrogen sulfide concentration is less than 1000ppm, removal precision is less than 0.1ppm.When saturated with hydrogen sulfide, the scavenger can be regenerated under the purge of oxygen-free atmosphere, restore removal capacity, regeneration temperature is 250~300 ℃.Compared with prior art, the hydrogen sulfide removing agent prepared in the present application has more prominent hydrogen sulfide removal capacity, adsorption capacity is increased by 3-5 times, and regeneration cycle is prolonged by 2-5 times.

The invention provides a thermal management method and system of a battery pack and a vehicle, and relates to the technical field of batteries. The thermal management method of the battery pack is used for a thermal management system of the battery pack, the thermal management system is configured to be switched between a first circulation mode and a second circulation mode, and the thermal management method of the battery pack comprises the following steps: determining that the battery pack has a refrigeration demand; determining whether the thermal management system meets a mode switching condition or not; if not, controlling the thermal management system to operate in a first circulation mode or a second circulation mode; and if yes, the heat management system is controlled to be switched between the first circulation mode and the second circulation mode. According to the thermal management method of the battery pack, the switching frequency of the thermal management system between the first circulation mode and the second circulation mode is reduced, so that the impact frequency of the internal structure of the thermal management system is reduced, and the service life of the thermal management system is prolonged.

The invention belongs to the technical field of nuclear power, and particularly relates to a high-voltage frequency converter harmonic control method and a filter. According to the method, the harmonic component in the output voltage of the frequency converter can be effectively reduced. According to the method disclosed by the invention, a relatively high fundamental frequency is obtained through modulation, and the voltage utilization rate is improved, so that the torque ripple of the motor is remarkably reduced. Under the same switching frequency, the method disclosed by the invention can generate the optimal output waveform. While the waveform quality is ensured, the switching frequency and the switching loss are reduced, and the overall efficiency of the system is improved.

The present invention belongs to the field of flexible direct current valve control, and specifically relates to a flexible direct current valve control system and a communication redundancy control method. The present invention sets link redundancy between communication nodes, solves the risk of system failure caused by a single link failure from the physical link layer, and causes system exit. In the event of a channel failure, the system is not directly switched, but the temporary failure of the channel is eliminated by restarting first, avoiding system switching caused by temporary failures that can be self-recovered by restarting, and reducing the system switching frequency; two priority reset methods are used, first restarting with less impact on the system and transmission process, and then the next restart method is performed if it is still not recovered after restarting, so that the channel recovery time and system disturbance can be reduced; and there is no priority for fault judgment and restart between two redundant channels, so that the failure of each channel can be eliminated as much as possible during the system operation, reducing the impact on the overall redundancy of the system.

This invention discloses a series-parallel type switched linear composite envelope tracking power supply, comprising a multilevel converter (VSC), a linear amplifier (VLA), and a switching converter (CSC). The multilevel converter (VSC) and the linear amplifier (VLA) are connected in series, and the switching converter (CSC) and the linear amplifier (VLA) are connected in parallel. The multilevel converter (VSC) tracks the envelope signal and outputs a stepped-wave voltage to fit the load voltage v. o Simultaneously, the stepped waveform voltage output by VSC serves as the input voltage of CSC; the linear amplifier VLA realizes the load voltage v o For the reference signal v ref The switching converter (CSC) outputs current to match the load current. This invention significantly reduces the switching frequency of the CSC and the voltage stress on the switching transistor without increasing the complexity of the series-parallel ET power supply, thereby improving the overall efficiency of the ET power supply.

The utility model relates to a charging protection circuit and a charger. The charging protection circuit comprises a charging switch control module and a square wave generation module, a first end of the charging switch control module is connected with an input power supply, a second end of the charging switch control module is connected with an input end of the square wave generation module, and an output end of the square wave generation module is connected with a third end of the charging switch control module. The fourth end of the charging switch control module is connected with the battery; the square wave generation module comprises a thermistor; when the charging switch control module controls the charging path to be conducted, the resistance value of the thermistor is increased along with temperature rise so as to adjust the period of a square wave signal input to the third end of the charging switch control module by the square wave generation module, and the charging switch control module is used for adjusting the switching frequency of the charging path according to the period of the square wave signal. The charging protection circuit can reduce the temperature of the battery.

The present invention belongs to the field of electromagnetic drive power supply technology, and specifically relates to an ultra-high-speed electromagnetic drive power supply system and control method based on a power flow converter, which aims to solve the problems of high switching frequency, weak current carrying capacity, and large output current harmonics of the converter powered by the existing electromagnetic drive system. The present invention includes: an energy storage device connected to the primary side of the input transformer to provide energy for the system; m input transformer secondary windings of the input transformer are respectively connected to the input ends of m current source converters; m output transformer secondary windings of the output transformer are respectively connected to the output ends of m current source converters; the output transformer primary is connected to the load for supplying power to the load. The switching frequency of the power semiconductor device on the rectifier side of the present invention is equal to the input transformer voltage frequency, and the switching frequency of the power semiconductor device on the inverter side is equal to the reference current frequency. The switching frequency is low, the current carrying capacity is strong, and the current harmonic content is small.

The application discloses a low-switching-frequency three-dimensional satisfactory space optimization model predictive control method and device, and the method comprises the following steps: dividing the multi-target optimization of a frequency converter system into main control target optimization and auxiliary control target optimization; estimating the state of the main control target through a control system mathematical model; constructing a three-dimensional satisfactory space according to the tracking deviation of the main control target, and implementing satisfactory space optimization on the main control target to select a candidate switching vector; selecting a corresponding processing method according to the number of the candidate switching vectors, so as to obtain an optimized switching state; and the processing method comprises a maximum average residence time method and a minimum ordering average method. The main control target and the auxiliary control target are divided into two independent optimization levels, so that the complex weight coefficient design and debugging process are effectively avoided. In addition, through the two-level optimization strategy, high-performance control of the motor is realized, and the switching frequency is effectively reduced, so that the optimization balance of energy efficiency and performance is realized.

The present application proposes a method and system for controlling the rapid commissioning of energy-consuming devices based on the limit approximation method, the method comprising: real-time monitoring of the DC voltage of an offshore wind power flexible direct current transmission system connected to an energy-consuming device; when it is monitored that the DC voltage of the flexible direct current transmission system is greater than the first DC voltage threshold corresponding to the flexible direct current transmission system, the limit approximation method is used to determine the energy-consuming resistor value required for the energy-consuming device; and the energy-consuming device is controlled to be rapidly commissioned based on the energy-consuming resistor value required for the energy-consuming device. The technical solution proposed in the present application can significantly reduce the switching frequency of the energy-consuming device, extend the service life of the energy-consuming device, and realize the dynamic regulation of the power absorption of the energy-consuming device.

The present invention relates to a shore-based variable frequency power supply micro-power consumption full-power test method and system under weak power grid conditions, wherein the power supply variable frequency power supply V1 includes a frequency converter VFP1, the shore-based variable frequency power supply V2 includes a frequency converter VFP2, the energy-feeding load power supply V3 includes a frequency converter VFP3, the input end of the frequency converter VFP1 is connected to the shore-based high-voltage power supply, the output end of the frequency converter VFP1 is connected to the input end of the frequency converter VFP2, the output end of the frequency converter VFP2 is connected to the input end of the frequency converter VFP3, and the output end of the frequency converter VFP3 is respectively connected to the output end of the frequency converter VFP1 and the input end of the frequency converter VFP2; the energy-feeding load power supply V3 is used as a simulated load to test the shore-based variable frequency power supply V2, and after the shore-based variable frequency power supply V2 is tested, the shore-based variable frequency power supply V2 is put into use. The advantages of the present invention are: after the test loop forms a loop, no actual work is required, only the current needs to be increased to a predetermined test value, the energy consumption is small, and the power grid does not need to provide a large capacity.

The invention provides a scene component marking method and device, electronic equipment and a readable storage medium, and the method comprises the steps: displaying a level trial playing interface in a level trial playing mode; the level trial playing interface comprises a front sight mark and a virtual level scene edited in a level editing mode; the virtual level scene comprises at least one scene component; in response to the marking operation, determining the scene component aimed at by the front sight mark as a to-be-marked target component, and marking the target component; responding to the mode switching instruction, switching to a level editing mode, and displaying a level editing interface; and displaying the mark prompt identifier at the target component in the level editing interface. Therefore, the frequency of switching between the level editing interface and the level trial playing interface of a player is reduced, the situation that the player forgets the scene component needing to be modified is avoided, the step of repeatedly searching the scene component is reduced, and the editing and adjusting efficiency of the virtual level scene is improved.

This invention discloses an online water quality monitoring system and control method, belonging to the field of water quality monitoring technology. It includes a processing module, a combined valve, a metering device, a peristaltic pump, and a digester. The metering device has a comprehensive metering chamber, a first auxiliary metering chamber, and a second auxiliary metering chamber, respectively corresponding to the isolated metering of non-strongly corrosive reagents, strong acid reagents, and strong alkali or strong oxidizing reagents. Each chamber is equipped with a photoelectric liquid level sensor to achieve precise volume determination. The processing module controls the injection of wastewater in at least three closed-loop batches. The first batches act as a carrier liquid to push reagents and dilute residues, while the last closed-loop batch replenishes the total volume and cleans the pipelines and chambers of residues, using wastewater to replace the cleaning fluid for self-cleaning. This invention can achieve multi-chamber isolated metering, reagent premixing, parallel detection with dual digesters, or time-sharing detection with a single digester, effectively avoiding cross-reactions between acids / alkalis and redox reagents, reducing cleaning fluid consumption and wastewater production, and improving the stability, detection efficiency, and equipment reliability of multi-parameter online monitoring.