Ice maker compressor depressurization starting method

Abstract

The invention discloses a step-down starting method for an ice maker compressor, which aims at the problem of poor reliability of a traditional starting device circuit board, adopts a multi-stage damping step-down starting technology and is divided into three stages of pre-excitation, damping transition and stable operation. In the pre-excitation stage, the peak value of the starting current is limited to be below 35% of the rated current through double-frequency superposition pulses; in the damping transition stage, predictive damping regulation and control are utilized, the damping coefficient and voltage are adjusted in advance, and smooth transition is achieved; in the stable operation stage, a multi-phase reverse intervention technology is adopted, reverse pulses are applied, three-dimensional magnetic field balance is constructed, and the current peak is reduced by 40%. Through technologies such as nonlinear damping decline, the heat loss is reduced by 30%, the starting and stopping success rate reaches 98%, the starting time is shortened by 12%, the method is suitable for a high-power ice maker compressor, and the reliability and efficiency are remarkably improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of starting control of ice machine compressors, and relates to a method for reducing voltage and starting an ice machine compressor. Background Art

[0002] As a core component in the refrigeration system, ice machine compressors are widely used in industrial refrigeration, cold chain transportation, food processing and other fields. Their starting performance directly affects the operation stability and production efficiency of the equipment. However, there are many technical defects in the starting methods of traditional ice machine compressors. Especially in high-power equipment, the reliability problem of the starting device circuit board is particularly prominent. Taking the 30000 unit as an example, the traditional starting device used in its No. 2 ice machine controls the thyristor opening to adjust the current through a circuit board. Due to the large current impact and frequent load fluctuations during starting, the circuit board is prone to failure due to thermal stress, high-voltage spikes or torque imbalance, resulting in a decrease in the success rate of starting and stopping, and seriously affecting production continuity.

[0003] In the prior art, common methods for reducing voltage and starting include star-delta starting and soft starter technology. Star-delta starting reduces the starting current to about 1 / 3 of the rated current by switching the connection method of the motor windings (from star to delta) through contactors. This method is simple and practical, but it is prone to secondary current impact during the switching process and cannot dynamically adapt to load changes, making it difficult to completely solve the reliability problem of the circuit board. Soft starters use thyristors to gradually adjust the voltage to achieve smooth starting. Compared with star-delta starting, the current impact is smaller, but the adjustment accuracy depends on the stability of the circuit board. Once the circuit board is damaged due to overload or thermal stress, the starting process will still be interrupted. In addition, the control complexity of soft starters increases the maintenance cost and their adaptability to high-power ice machine compressors is limited.

[0004] In recent years, Pulse Width Modulation (PWM) technology has been widely used in the field of motor control. By adjusting the voltage through high-frequency pulses, it can effectively reduce current fluctuations. However, PWM technology is mostly used for variable frequency control during the running stage of the motor and is less applied in the starting stage. Moreover, its high-frequency characteristics may exacerbate the thermal load of the circuit board and do not fundamentally solve the reliability problem of the starting device. In addition, some documents mention suppressing current fluctuations through damping circuits, but these technologies mostly focus on small-power electronic devices and are difficult to be directly extended to the starting control of high-power ice machine compressors. Magnetic field regulation technology is also applied in some motor drives, such as suppressing magnetic field overshoot through phase adjustment, but the prior art has not combined it with the starting process to form a systematic solution.

[0005] In summary, the existing starting technologies for ice machine compressors have the following limitations: First, the starting current impact is relatively large, which is likely to cause the circuit board to be overloaded or burned out; second, there is a lack of dynamic load adaptability, and the starting and stopping stability is insufficient; third, the problems of thermal stress and high-voltage spikes have not been effectively solved, resulting in a short lifespan of the circuit board; fourth, most of the existing voltage reduction methods are single-stage control, making it difficult to comprehensively optimize the starting process. Taking the No. 2 ice machine of the 30000 unit as an example, the failure rate of the circuit board of its traditional starting device is as high as over 20%, and the economic loss caused by shutdown maintenance each year exceeds 100,000 yuan, with a significant decline in production efficiency. Therefore, there is an urgent need for an innovative voltage reduction starting method that can improve the reliability of the circuit board and the operating stability of the equipment while reducing the starting impact.

[0006] Although certain progress has been made in the field of voltage reduction starting in the existing technologies, there is no systematic and multi-level solution to the problem of poor reliability of the circuit board of the starting device for high-power ice machine compressors. Although the traditional star-delta starting and soft starter technologies have certain effects in industrial applications, their static control modes are difficult to cope with current fluctuations and magnetic field overshoot phenomena under complex load conditions. In addition, although the high-frequency characteristics of PWM technology can optimize the energy efficiency during the operation stage, they have not been fully exploited for low-impact control during the starting stage. Although the application of damping technology in electronic circuits can suppress fluctuations, its specific implementation method in the starting of ice machine compressors is still blank. The potential of magnetic field regulation technology has not been fully developed either. In particular, the idea of achieving three-dimensional magnetic field balance through step-by-step intervention in multi-phase motors is rarely mentioned in the existing literature. These technical defects lead to the inability of the existing methods to completely solve the problem of high failure rate of the circuit board during the starting process of ice machine compressors, and there is an urgent need for a brand-new technical solution to comprehensively improve the starting performance through multi-level control, intelligent regulation, and energy optimization. Summary of the Invention

[0007] In view of this, the purpose of the present invention is to provide a voltage reduction starting method for ice machine compressors. Aiming at the technical problem of poor reliability of the circuit board of the traditional starting device, through multi-level damping voltage reduction starting technology, combined with innovative means such as dual-frequency superposition pulse, predictive damping regulation, and multi-phase reverse intervention, the electrical impact during the starting process is reduced, and the reliability and production efficiency of starting and stopping are improved.

[0008] To achieve the above purpose, the present invention provides the following technical solutions:

[0009] A voltage reduction starting method for ice machine compressors adopts a multi-level damping voltage reduction starting method, divides the starting process into a pre-excitation stage, a damping transition stage, and a stable operation stage, and gradually releases the starting energy through hierarchical damping to reduce the electrical impact;

[0010] In the pre-excitation stage, a damping signal is applied through dual-frequency superposition pulse technology, in which 5-15Hz low-frequency pulse is the main wave, superimposed with 50-100Hz high-frequency disturbance, to optimize the efficiency of magnetic field establishment, limit the starting current peak to less than 35% of the rated current, and avoid circuit overload;

[0011] In the damping transition stage, predictive damping control technology is used to adjust the damping coefficient and voltage to 50%-80% of the rated value 0.1s-0.5s in advance according to the real-time speed and current trends through an embedded prediction model to achieve a smooth transition of current and torque.

[0012] During the stable operation stage, multi-phase reverse intervention technology is adopted to apply 0.02s-0.1s reverse pulses in steps in the three-phase motor to establish a three-dimensional magnetic field balance, suppress magnetic field overshoot, ensure stability during full-voltage operation, and improve starting and stopping reliability.

[0013] Furthermore, in the pre-excitation stage, nonlinear damping reduction technology is used to dynamically reduce the damping strength according to the inverse square law of the speed, so that the starting current presents a smooth quadratic curve change, reducing the starting heat loss by at least 30%, and solving the problem of circuit board failure due to thermal stress.

[0014] Furthermore, the dual-frequency superposition pulse technology generates a damping signal through pulse width modulation. The pulse width is dynamically adjusted between 0.05ms-0.5ms, and the amplitude ratio of low-frequency pulses to high-frequency disturbances is 3:1 to 5:1, which further optimizes the motor magnetic field establishment process and reduces current fluctuations to within ±4%.

[0015] Furthermore, the predictive damping control technology in the damping transition stage calculates the optimal damping coefficient through an embedded prediction model based on historical load data and real-time current. The damping coefficient ranges from 0.1 to 0.8, which improves the voltage response speed by more than 15% and prevents the circuit board from being damaged due to sudden load changes.

[0016] Furthermore, the multi-phase reverse intervention technology applies reverse pulses in steps according to the number of motor phases, with an interval of 0.01s-0.03s between each phase pulse, forming a three-dimensional magnetic field stabilization effect, reducing current spikes by more than 40%, and solving the problem of traditional circuit boards failing due to high-voltage spikes.

[0017] Furthermore, during the pre-excitation stage, the frequency of the dual-frequency pulse is gradually increased from 5Hz to 15Hz, and high-frequency disturbances are superimposed synchronously, so that the motor magnetic field is gradually established and the starting torque fluctuation is controlled within ±4%, avoiding the start-stop failure of traditional circuit boards due to torque imbalance.

[0018] Furthermore, during the damping transition stage, through the collaborative optimization of predictive damping regulation and voltage, the motor torque is smoothly transitioned, and the torque fluctuation is controlled within ±5%, while the startup time is shortened by more than 12%, solving the problem that the production efficiency is affected by unstable start and stop of the circuit board.

[0019] Furthermore, during the damping transition stage, the dynamic energy transfer technology is introduced. By connecting a shunt energy storage unit to absorb the excess current energy during startup, the energy storage efficiency reaches more than 15%, which is used for subsequent heat dissipation or pre-excitation power supply, reducing the thermal stress impact on the control system.

[0020] Furthermore, it is applied to high-power ice machine compressors, including but not limited to 30000 units.

[0021] The beneficial effects of the present invention are as follows:

[0022] 1. Significantly reduce the starting current impact and improve the reliability of the circuit board

[0023] Through the dual-frequency superposition pulse technology, the peak value of the starting current is limited to less than 35% of the rated current, which is lower than that of the traditional star-delta starting (about 60%-70%) and soft starter (about 50%). The non-linear damping decreasing technology makes the current change in a smooth quadratic curve, avoiding sudden impact, reducing the heat loss by more than 30%, effectively reducing the thermal stress damage of the circuit board, and extending its service life by at least 50%.

[0024] 2. Optimize the starting and stopping stability and reduce production interruptions

[0025] The predictive damping regulation technology adjusts the damping coefficient and voltage 0.1s - 0.5s in advance, combined with the multi-phase reverse intervention technology to suppress the magnetic field overshoot, reducing the current peak by more than 40% and controlling the torque fluctuation within ±5%. Compared with the traditional method with a starting and stopping success rate of 85%-90%, the success rate of the present invention is increased to more than 98%, significantly reducing the downtime caused by startup failures, and reducing the annual average downtime loss by about 80%.

[0026] 3. Improve production efficiency and shorten the startup time

[0027] Through the gradual increase of the frequency of the dual-frequency pulse and the collaborative optimization of predictive regulation and voltage, the startup time is shortened by more than 12%. For example, the startup time of the No. 2 ice machine of the 30000 unit is reduced from 8 seconds by the traditional method to about 7 seconds, the number of start and stop times per day is increased by 10%, and the production efficiency is increased by 25%, bringing significant economic benefits to the enterprise.

[0028] 4. Balance energy saving and system protection

[0029] The dynamic energy transfer technology transfers the excess current energy in the damping transition stage to the energy storage unit, with an energy storage efficiency of over 15%, which can be used for subsequent heat dissipation or pre-excitation power supply, saving about 5%-8% of energy annually. At the same time, reducing electrical shock and thermal stress decreases the maintenance frequency of the control system, and the maintenance cost is reduced by 20%-30%.

[0030] 5. Wide applicability and technical universality

[0031] This method is applicable to high-power ice machine compressors, not limited to 30,000-unit machines, and can adapt to equipment with different powers and load conditions, having good promotion value.

[0032] Other advantages, objectives, and features of the present invention will be described to some extent in the subsequent specification, and to some extent, will be obvious to those skilled in the art based on the study of the following text, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the following specification. Detailed implementation manners

[0033] The following uses specific specific examples to illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation manners, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0034] A quick start-stop hydrogenation method for a skid-mounted hydrogenation station based on a liquid-driven compressor, comprising:

[0035] (1) Construct a skid-mounted hydrogenation station system, which includes a hydrogen storage module, a liquid-driven compressor module, and a hydrogenation module. The hydrogen storage module is composed of a high-pressure storage tank in series with a low-pressure buffer tank, and a dynamic liquid control valve is installed in the buffer tank to adjust the pressure according to the fluctuation of the hydrogen supply flow rate;

[0036] (2) Set up the liquid-driven compressor module, and the module operates in combination with a gas-liquid separator through a hydraulic drive unit. The hydraulic drive unit adjusts the movement of the compressor piston through a two-way hydraulic pump;

[0037] (3) Implement quick start-stop control, and run a dynamic response algorithm through an embedded controller to adjust the operating state of the liquid-driven compressor in real time according to the hydrogenation demand.

[0038] Example 1: Centralized hydrogenation station in a green park

[0039] In this embodiment, a flat site of 200 square meters is selected in a green park, and a skid-mounted hydrogen refueling station system based on a liquid-driven compressor is constructed to meet the centralized hydrogen refueling needs of hydrogen forklifts, logistics vehicles and experimental equipment in the park.

[0040] 1. System construction

[0041] The system consists of a hydrogen storage module, a liquid-driven compressor module and a hydrogenation module. The hydrogen storage module includes a high-pressure storage tank and a low-pressure buffer tank. The high-pressure storage tank has a capacity of 500kg, a rated pressure of 35MPa, and a pressure relief valve installed on the top (the valve core diameter is 20mm, and the release pressure is set to 40MPa). The low-pressure buffer tank has a capacity of 100kg, a rated pressure of 5MPa, and a built-in dynamic hydraulic control valve. The dynamic hydraulic control valve adopts a stainless steel valve body with a valve core diameter of 15mm. It is driven by a hydraulic servo mechanism. The servo mechanism is equipped with a bidirectional hydraulic cylinder (cylinder diameter 50mm, stroke 30mm) and a flow sensor (measuring range 0-1000L / min, accuracy ±1%). The hydraulic cylinder is connected to the external hydraulic station through a high-pressure oil pipe (pressure resistance 60MPa). The liquid-driven compressor module includes a hydraulic drive unit, a compression cylinder and a gas-liquid separator. The hydraulic drive unit is equipped with a bidirectional hydraulic pump (flow range 0-50L / min, pressure 20MPa). The pump is driven by a servo motor (power 5kW, speed range 0-3000rpm). The high-pressure hydraulic pipeline (inner diameter 10mm, pressure resistance 30MPa) is connected to the compression cylinder. The compression cylinder piston has a diameter of 80mm and a stroke of 100mm. The gas-liquid separator adopts a porous plate structure (aperture 2mm, hole spacing 5mm). The hydrogenation module is connected to the liquid-driven compressor module through an adaptive quick-release interface. The interface adopts a wedge-shaped locking mechanism (locking force 15kN) and a liquid-tight sealing ring (material fluororubber, pressure resistance 20MPa). The installation time of a single module is about 3 hours, and the total construction period is 20 days.

[0042] 2. Hydrogen storage and supply regulation

[0043] The hydrogen storage module is linked to the hydrogen storage tank in the station through the tube bundle car (capacity 600kg, pressure 20MPa) to supply hydrogen. The tube bundle car is connected to the high-pressure storage tank through a quick connector (diameter 25mm). The dynamic hydraulic control valve adjusts the buffer tank pressure according to the flow sensor data. When the input flow of the tube bundle car suddenly changes from 500L / min to 800L / min, the hydraulic servo mechanism drives the valve core to move 10mm to the left through the two-way hydraulic cylinder, increasing the exhaust volume of the buffer tank and maintaining the pressure between 4-5MPa.

[0044] 3. Operation of liquid-driven compressor

[0045] The liquid-driven compressor module drives the piston to compress hydrogen through a two-way hydraulic pump. The pump alternately supplies liquid through a high-pressure hydraulic pipeline (length 2m) and a low-pressure return pipeline (length 1.5m). The hydraulic oil is controlled by a servo motor, and the initial flow rate is set to 30L / min. The compression cylinder raises the hydrogen pressure from 5MPa to 12MPa. The gas-liquid mixture generated during the compression process is separated by a gas-liquid separator. The porous plate intercepts the liquid droplets to the bottom drain port (diameter 10mm). The liquid level self-monitoring function monitors the liquid level of the hydraulic drive unit fuel tank through a liquid level sensor (range 0 - 500mm, accuracy ±2mm). When the liquid level exceeds 400mm, the overflow valve (set pressure 25MPa) automatically opens to discharge the excess hydraulic oil to the recovery tank (capacity 20L).

[0046] 4. Quick start and stop control

[0047] The embedded controller (processor ARM Cortex-A53, frequency 1.5GHz) runs a dynamic response algorithm, which real-time collects the pressure demand signal of the hydrogenation module (through a pressure sensor, range 0 - 15MPa, accuracy ±0.5%) and the flow data of the hydrogen storage module (through a flow sensor). The algorithm constructs an instantaneous operating condition vector (including pressure 12MPa and flow rate 600L / min), predicts the demand change within the next 5 seconds (such as the pressure rising to 13MPa) through a feedforward control model, and the feedback adjustment mechanism adjusts the liquid supply frequency of the two-way hydraulic pump to 35L / min, and the piston movement frequency increases from 10 times / min to 15 times / min to achieve the quick start and stop of the compressor.

[0048] 5. Hydrogenation pressure switching

[0049] The hydrogenation module supports wide-range filling through a multi-stage pressure distribution device. The high-pressure filling channel (diameter 8mm, pressure 12MPa) and the low-pressure filling channel (diameter 12mm, pressure 3MPa) are respectively connected to the hydrogenation gun. The liquid-controlled switching valve (response time 0.2 seconds) switches the channels according to the forklift (demand 3MPa) and the logistics vehicle (demand 12MPa), and the switching process is driven by a hydraulic control unit (pressure 15MPa).

[0050] 6. Operation and application

[0051] After the system runs, the daily hydrogenation capacity reaches 500kg / 12h. The dynamic liquid control valve and the two-way hydraulic pump work together. When the hydrogenation demand of the forklift is interrupted, the algorithm drives the hydraulic pump to stop, and the compressor stops running within 0.5 seconds; when the experimental equipment needs 12MPa hydrogen, the compressor starts within 0.3 seconds and stably outputs, supporting the durability experiment of the hydrogen fuel cell stack.

[0052] Example 2: Temporary hydrogenation station in industrial park

[0053] In this embodiment, a 150-square-meter temporary site is selected in an industrial area to construct a skid-mounted hydrogen refueling station based on a liquid-driven compressor, which is used to support the hydrogen refueling needs of commuter vehicles and experimental equipment in the short term.

[0054] 1. System construction

[0055] The system includes a hydrogen storage module, a liquid-driven compressor module, and a hydrogen refueling module. The hydrogen storage module is composed of a high-pressure storage tank (300 kg, 20 MPa) and a low-pressure buffer tank (80 kg, 3 MPa) connected in series. A pressure relief valve (valve core diameter 15 mm, relief pressure 25 MPa) is installed on the top of the high-pressure storage tank. A dynamic liquid control valve is built into the low-pressure buffer tank, with a valve core diameter of 12 mm, driven by a hydraulic servo mechanism. A two-way hydraulic cylinder (cylinder diameter 40 mm, stroke 25 mm) is connected to a flow sensor (range 0 - 800 L / min, accuracy ±1%), and the hydraulic station supplies oil through an oil pipe (pressure resistance 50 MPa). The liquid-driven compressor module includes a hydraulic drive unit (two-way hydraulic pump, flow range 0 - 40 L / min, pressure 15 MPa), a compression cylinder (piston diameter 70 mm, stroke 80 mm), and a gas-liquid separator (porous plate pore diameter 1.5 mm, pore distance 4 mm). The two-way hydraulic pump adjusts the hydraulic oil flow through a servo motor (power 4 kW, speed 0 - 2500 rpm), and a high-pressure hydraulic pipeline (inner diameter 8 mm) connects the compression cylinder. The hydrogen refueling module is connected through an adaptive quick-connect interface. A wedge locking mechanism (locking force 12 kN) and a liquid-tight sealing ring (pressure resistance 15 MPa) fix the module. The installation time for a single module is 2.5 hours, and the total construction period is 15 days.

[0056] 2. Hydrogen storage and hydrogen supply regulation

[0057] The hydrogen storage module is linked with the hydrogen storage tank through a tube trailer (capacity 400 kg, pressure 15 MPa), and the tube trailer inputs hydrogen through a quick connector (diameter 20 mm). The dynamic liquid control valve adjusts the pressure according to the data of the flow sensor. When the input flow rate drops from 400 L / min to 200 L / min, the hydraulic servo mechanism drives the valve core to move 8 mm to the right, reducing the exhaust volume of the buffer tank and maintaining the pressure at 2.5 - 3 MPa.

[0058] 3. Operation of the liquid-driven compressor

[0059] The liquid-driven compressor drives the piston through a two-way hydraulic pump. The pump alternately supplies liquid through a high-pressure hydraulic pipeline (length 1.8 m) and a low-pressure return pipeline (length 1.2 m). The initial flow rate is 25 L / min, and the compression cylinder raises the hydrogen pressure from 3 MPa to 10 MPa. The gas-liquid separator separates the gas-liquid mixture, and the liquid droplets are discharged through the bottom drain port (diameter 8 mm). A liquid level sensor (range 0 - 400 mm, accuracy ±2 mm) monitors the liquid level in the fuel tank. When the liquid level exceeds 350 mm, the overflow valve (set pressure 20 MPa) opens to discharge the hydraulic oil to a recovery tank (capacity 15 L).

[0060] 4. Quick start-stop control

[0061] The embedded controller runs a dynamic response algorithm, collects the pressure demand of the hydrogenation module (sensor range 0 - 12 MPa, accuracy ±0.5%) and the flow data of the hydrogen storage module, and constructs a working condition vector (pressure 10 MPa, flow rate 300 L / min). The feedforward control model predicts the demand change (such as the pressure drops to 9 MPa), and the feedback adjustment mechanism adjusts the flow rate of the hydraulic pump to 20 L / min, and the piston frequency decreases from 8 times / min to 5 times / min to achieve quick shutdown.

[0062] 5. Hydrogenation pressure switching

[0063] The hydrogenation module supports filling through a multi-stage pressure distribution device. The high-pressure filling channel (pressure 10 MPa) and the low-pressure filling channel (pressure 5 MPa) are respectively connected to the hydrogenation gun. The liquid control switching valve switches the channels according to the commuter vehicle (5 MPa) and the experimental equipment (10 MPa), and the switching time is 0.15 seconds.

[0064] 6. Operation and application

[0065] After the system runs, the daily hydrogenation capacity is 400 kg / 12 h. The dynamic liquid control valve and the bidirectional hydraulic pump work together. When the hydrogenation of the commuter vehicle ends, the compressor shuts down within 0.4 seconds; when the experimental equipment starts, the compressor starts within 0.2 seconds and outputs hydrogen at 10 MPa to support the durability test of the internal combustion engine. After the operation ends, the disassembly time of the system is about 10 hours.

[0066] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the present technical solution, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A method for starting a refrigerating compressor under reduced voltage, characterized in that, Adopt a multi-stage damping step-down starting method, divide the starting process into a pre-excitation stage, a damping transition stage, and a stable operation stage, and gradually release the starting energy through hierarchical damping to reduce electrical shock; In the pre-excitation stage, apply a damping signal through a dual-frequency superposition pulse technique, where the 5 - 15 Hz low-frequency pulse is the main wave, and a 50 - 100 Hz high-frequency perturbation is superimposed to optimize the magnetic field establishment efficiency, limit the starting current peak to below 35% of the rated current, and avoid circuit overload; In the damping transition stage, utilize the predictive damping control technique. According to the real-time speed and current trend through an embedded prediction model, adjust the damping coefficient and voltage to 50% - 80% of the rated value 0.1 s - 0.5 s in advance to achieve a smooth transition of current and torque; In the stable operation stage, adopt a multi-phase reverse intervention technique, and apply reverse-phase pulses for 0.02 s - 0.1 s step by step in a three-phase motor to construct a three-dimensional magnetic field balance, suppress magnetic field overshoot, ensure stability during full-voltage operation, and improve the starting and stopping reliability.

2. The step-down starting method of an ice machine compressor according to claim 1, wherein, In the pre-excitation stage, adopt a non-linear damping decreasing technique, dynamically reduce the damping intensity according to the inverse square law of speed, make the starting current show a smooth quadratic curve change, reduce the starting heat loss by at least 30%, and solve the problem of circuit board failure due to thermal stress.

3. A starting method for reducing the voltage of an ice machine compressor according to claim 1, characterized in that, The dual-frequency superposition pulse technique generates a damping signal through pulse width modulation, the pulse width is dynamically adjusted between 0.05 ms - 0.5 ms, and the amplitude ratio of the low-frequency pulse to the high-frequency perturbation is 3:1 to 5:1, further optimizing the motor magnetic field establishment process and reducing the current fluctuation to within ±4%.

4. A method for starting a refrigerator compressor with reduced voltage according to claim 1 or 3, characterized in that, The predictive damping control technique in the damping transition stage calculates the optimal damping coefficient through an embedded prediction model based on historical load data and real-time current, and the damping coefficient range is 0.1 - 0.8, which improves the voltage response speed by more than 15% and prevents the circuit board from being damaged due to sudden load changes.

5. A starting method for reducing the voltage of an ice machine compressor according to claim 1, characterized in that, The multi-phase reverse intervention technique applies reverse-phase pulses step by step according to the number of motor phases, with a pulse interval of 0.01 s - 0.03 s for each phase, forming a three-dimensional magnetic field stabilization effect, reducing the current peak by more than 40%, and solving the problem of traditional circuit board failure due to high-voltage spikes.

6. A method for starting a refrigerating compressor under reduced voltage according to claim 1, characterized in that In the pre-excitation stage, through the frequency gradual increase technique of dual-frequency pulses, increase from 5 Hz to 15 Hz and synchronously superimpose high-frequency perturbations to gradually establish the motor magnetic field, control the starting torque fluctuation within ±4%, and avoid starting and stopping failures of traditional circuit boards due to torque imbalance.

7. A method for starting a refrigerator compressor with reduced voltage according to claim 1, characterized in that In the damping transition stage, through the collaborative optimization of predictive damping control and voltage, make the motor torque transition smoothly, control the torque fluctuation within ±5%, and at the same time shorten the starting time by more than 12%, solving the problem that the production efficiency is affected due to unstable starting and stopping of the circuit board.

8. A method for step-down starting of an ice machine compressor according to claim 1, characterized in that Introduce a dynamic energy transfer technique in the damping transition stage, absorb the excess current energy during the starting process through a parallel energy storage unit, and the energy storage efficiency reaches more than 15%, which is used for subsequent heat dissipation or pre-excitation power supply, reducing the thermal stress impact on the control system.

9. A method for starting a refrigerating compressor under reduced voltage according to claim 1, characterized in that, Applied to high-power ice machine compressors, including but not limited to 30000 units.