Start control method and system of mobile ice melting device

Abstract

The invention provides a starting control method and system of a mobile ice melting device, and the control method is applied to a control system comprising a power supply device, an excitation adjusting device and a control switch, and specifically comprises the steps: starting the power supply device, building the connection between the mobile ice melting device and power supply equipment when a generator of the power supply device reaches a preset condition, and starting the excitation adjusting device; putting a no-load transformer; starting the excitation adjusting device, and collecting the generator rotating speed of the power supply device in real time; based on the generator rotating speed of the power supply device, combining the starting time to construct an excitation regulation input strategy; the excitation adjusting device responds to the input strategy and adjusts the output voltage of the power supply device; and when the output voltage of the power supply device reaches the rated voltage, connection between the mobile ice melting device and the ice melting line is established. By adjusting the starting time sequence of the mobile ice melting device and setting dynamic excitation adjustment, excitation inrush current and voltage impact are effectively reduced, misoperation of protection action is avoided, and reliable starting of the mobile ice melting device is guaranteed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mobile ice melting, in particular to a starting control method and system of a mobile ice melting device. BACKGROUND

[0002] In the winter operation of the power system, the mobile ice melting device is a key equipment for coping with the icing disaster of the transmission line and the equipment of the substation. The traditional starting process of the mobile ice melting device mainly includes: starting the prime mover of the power supply device and dragging the generator to increase the rotating speed of the generator from 0 to the rated rotating speed, inputting the exciter of the generator, gradually increasing the excitation current of the generator, and increasing the terminal voltage of the generator to the rated voltage, closing the circuit breaker on one side of the power supply device to input the no-load transformer, and then closing the circuit breaker at one end of the mobile ice melting device to input the rectifier and the filter, and completing the starting of the mobile ice melting device.

[0003] During the starting process, when the no-load transformer is inputted, the terminal voltage of the generator is the rated voltage. Affected by the nonlinearity of the core of the transformer and the hysteresis effect, there is often a magnetizing inrush current when the transformer is inputted, and the current will suddenly increase. Once the excitation current is too large, it is easy to cause the misoperation of the protection action of the transformer or the generator, so that the generator exits the operation, causes the power input failure, and the mobile ice melting device cannot be started normally. SUMMARY

[0004] The present application aims to overcome the shortcomings of the prior art that the starting of the mobile ice melting device is affected by the magnetizing inrush current, which easily causes the misoperation of the protection action and causes the starting failure. The present application provides a starting control method and system of a mobile ice melting device, which effectively reduces the magnetizing inrush current and the voltage impact by adjusting the starting timing of the mobile ice melting device and setting the dynamic excitation regulation, avoids the misoperation of the protection action, and ensures the reliable starting of the mobile ice melting device.

[0005] The present application is achieved by the following technical solutions:

[0006] The starting control method of the mobile ice melting device comprises:

[0007] starting the power supply device, establishing the connection between the mobile ice melting device and the power supply device when the generator of the power supply device reaches a predetermined condition, and inputting the no-load transformer;

[0008] starting the excitation regulation device and collecting the rotating speed of the generator of the power supply device in real time;

[0009] based on the rotating speed of the generator of the power supply device, constructing an excitation regulation input strategy in combination with the starting time;

[0010] the excitation regulation device adjusts the output voltage of the power supply device in response to the input strategy;

[0011] When the output voltage of the power supply device reaches the rated voltage, the connection between the mobile ice-melting device and the ice-melting line is established.

[0012] By establishing the connection with the mobile ice-melting device and putting the no-load transformer after the generator of the power supply device reaches the predetermined condition, the load impact on the generator in the unstable state is avoided from the source, and a stable foundation is laid for subsequent excitation regulation. After starting the excitation regulation device, the generator speed is collected in real time, and the excitation regulation input strategy is constructed in combination with the starting time, so that the excitation regulation can dynamically adapt to the whole process from starting to stable operation of the generator, effectively reducing the excitation inrush current and voltage impact, reducing the protection action misoperation probability of the transformer or the generator, and ensuring the reliable start of the mobile ice-melting device.

[0013] Further, the excitation regulation input strategy is constructed in combination with the starting time based on the generator speed of the power supply device, comprising:

[0014] When the generator speed is equal to the rated speed and the current time is less than the starting time of the power supply device, the starting excitation regulator is selected to be put into operation, and a voltage control strategy is constructed in combination with the starting time and the output voltage at the generator end;

[0015] When the current time is greater than or equal to the starting time of the power supply device, the excitation regulator is selected to be put into operation, and a voltage control strategy is constructed according to the output voltage at the generator end.

[0016] Further, the excitation regulator is selected to be put into operation, and a voltage control strategy is constructed according to the output voltage at the generator end, comprising:

[0017] The starting excitation regulator generates an excitation voltage control signal according to the starting time;

[0018] The voltage difference between the excitation voltage control signal and the output voltage at the generator end is calculated, and an output adjustment signal is calculated in combination with the PID control according to the voltage difference calculation result;

[0019] An excitation current is output based on the adjustment signal, and the output voltage at the generator end is adjusted according to the excitation current.

[0020] Further, the excitation regulator is selected to be put into operation, and a voltage control strategy is constructed according to the output voltage at the generator end, comprising:

[0021] The output voltage at the generator end is collected in real time, and an excitation current adjustment signal is output through PID control in combination with the rated voltage of the generator;

[0022] An excitation current is output based on the excitation current adjustment signal, and the output voltage at the generator end is adjusted according to the excitation current.

[0023] Further, the starting control method further comprises:

[0024] After the connection between the mobile ice-melting device and the ice-melting line is established, the output voltage of the generator is adjusted according to the excitation regulator, and the voltage control strategy of the excitation regulator is adjusted according to the ice-melting progress of the mobile ice-melting device.

[0025] Further, the adjusting of the voltage control strategy of the excitation regulator according to the ice-melting progress of the mobile ice-melting device comprises:

[0026] dividing the ice-melting stages based on historical ice-melting information, and obtaining the load characteristics of each ice-melting stage;

[0027] real-time collection of operation information of the current mobile ice-melting device, combined with the load characteristics to identify the ice-melting stage in which the current ice-melting progress is located;

[0028] setting the voltage control target according to the ice-melting stage, adjusting the PID control parameters and the feedforward compensation parameters, and constructing the corresponding voltage control strategy according to the output voltage at the generator end.

[0029] Further, it further comprises:

[0030] real-time collection of environmental information of the ice-melting scene and operation information of the mobile ice-melting device, and identification of abnormal working conditions of the mobile ice-melting device;

[0031] When the abnormal working condition is identified, the ice-melting stage identification is reset.

[0032] Further, the starting power supply device, when the generator of the power supply device reaches a predetermined condition, establishes the connection between the mobile ice-melting device and the power supply equipment, comprising:

[0033] starting the power supply device, and putting the prime mover and the speed regulator of the power supply device into operation;

[0034] powered by the prime mover, and raising the speed of the generator according to the speed regulator;

[0035] When the speed of the generator is raised to the rated speed, the connection between the mobile ice-melting device and the power supply equipment is established.

[0036] The starting control system of the mobile ice-melting device is used to execute the starting control method of any one of the above, comprising:

[0037] The power supply device is used to supply power to the mobile ice-melting device;

[0038] The excitation regulating device is connected with the power supply device, and is used to formulate the input strategy of the excitation regulator according to the generator speed and the starting time of the power supply device, and to correspondingly adjust the output voltage of the power supply device;

[0039] The control switch at least comprises a first control switch and a second control switch,

[0040] The first control switch is arranged between the power supply device and the mobile ice melting device, and is used for establishing the connection between the mobile ice melting device and the power supply device when the generator of the power supply device meets the predetermined condition.

[0041] The second control switch is arranged between the mobile ice melting device and the ice melting circuit, and is used for establishing the connection between the mobile ice melting device and the ice melting circuit when the output voltage of the power supply device reaches the rated voltage.

[0042] Further, the excitation regulation device comprises:

[0043] The starting excitation regulator is connected with the power supply device, and is used for performing voltage adjustment according to the starting time of the power supply device and the output voltage at the generator end;

[0044] The excitation regulator is connected with the power supply device, and is used for performing voltage adjustment according to the output voltage at the generator end;

[0045] The selection unit is connected with the excitation regulator and the starting excitation regulator, and is used for selecting the excitation regulator or the starting excitation regulator to perform voltage adjustment according to the generator speed and the starting time of the power supply device.

[0046] The present application has the following beneficial effects:

[0047] (1) By establishing the connection with the mobile ice melting device after the generator of the power supply device meets the predetermined condition and inputting the no-load transformer, the load impact on the generator in the unstable state is avoided from the source, and a stable foundation is laid for subsequent excitation regulation. After the starting excitation regulation device is started, the generator speed is collected in real time, and the starting time is combined to construct an excitation regulation input strategy, so that the excitation regulation can dynamically adapt to the whole process from the starting to the stable operation of the generator, effectively reduces the excitation inrush current and voltage impact, reduces the protection action misoperation probability of the transformer or the generator, and protects the reliable starting of the mobile ice melting device.

[0048] (2) The excitation regulator is input in stages. The starting excitation regulator is input in the starting stage, the excitation voltage control signal is generated in combination with the starting time, and the excitation current is adjusted through the PID control output adjustment signal according to the difference between the signal and the output voltage at the generator end, so as to realize precise voltage control. After starting, the excitation regulator is switched to be input, and the control strategy is constructed according to the output voltage at the generator end. This stage-by-stage regulation mode can respond to different stages of load conditions, effectively suppress the excitation inrush current when the no-load transformer is input, control the voltage fluctuation amplitude in a small range, and significantly improve the voltage stability.

[0049] (3) The ice melting progress adjustment voltage control strategy combined with the mobile ice melting device enables the voltage control strategy to adapt to the load characteristics in different ice melting stages, ensures continuous and stable power supply during the ice melting process, and improves the ice melting efficiency. In addition, when abnormal conditions occur, the corresponding ice melting stage recognition can be reset to enhance the response capability to abnormal conditions, improve the fault tolerance rate, and ensure the normal operation of the mobile ice melting device under complex working conditions. BRIEF DESCRIPTION OF DRAWINGS

[0050] Figure 1 is a flowchart of the present application;

[0051] Figure 2 is a control logic diagram of starting the excitation regulator according to an embodiment of the present application;

[0052] Figure 3 is a general flowchart of generator excitation control during the starting process of a mobile ice melting device according to an embodiment of the present application;

[0053] Figure 4 is a structure diagram of a starting control system according to an embodiment of the present application;

[0054] Figure 5 is a generator voltage variation curve diagram during the starting process of one of the mobile DC ground wire ice melting devices according to an embodiment of the present application;

[0055] Figure 6 is a generator voltage variation waveform diagram during the starting process of one of the mobile DC ground wire ice melting devices according to an embodiment of the present application;

[0056] Figure 7 is a generator voltage variation curve diagram during the starting process of one of the mobile DC ground wire ice melting devices according to an embodiment of the present application;

[0057] Figure 8 is a transformer core magnetic flux variation diagram during the starting process of one of the mobile DC ground wire ice melting devices according to an embodiment of the present application;

[0058] Figure 9 is a magnetic flux variation diagram at the initial starting time during the starting process of one of the mobile DC ground wire ice melting devices according to an embodiment of the present application;

[0059] Figure 10 is a transformer core magnetic hysteresis loop diagram at the initial starting time during the starting process of one of the mobile DC ground wire ice melting devices according to an embodiment of the present application;

[0060] Figure 11is a schematic diagram of magnetic flux variation of a mobile DC ground wire ice melting device in a steady state in a late starting stage in a starting process of an embodiment of the present application;

[0061] Figure 12 is a schematic diagram of a transformer core hysteresis loop of a mobile DC ground wire ice melting device in a steady state in a late starting stage in a starting process of an embodiment of the present application;

[0062] Figure 13 is a schematic diagram of excitation current variation of a mobile DC ground wire ice melting device in a starting process of an embodiment of the present application;

[0063] Figure 14 is a schematic diagram of transformer current waveform of a mobile DC ground wire ice melting device in a starting initial time in a starting process of an embodiment of the present application;

[0064] Figure 15 is a schematic diagram of transformer current waveform of a mobile DC ground wire ice melting device in a steady state in a starting process of an embodiment of the present application;

[0065] Figure 16 is a transformer excitation inrush current waveform of a mobile DC ground wire ice melting device in a starting process of an embodiment of the present application.

[0066] Wherein: 1, power supply device, 11, prime mover, 12, generator, 13, speed regulator, 2, excitation regulating device, 21, starting excitation regulator, 22, excitation regulator, 23, selection unit, 3, control switch, 31, first control switch, 32, second control switch, 4, transformer, 5, ice melting line, 6, filter, 7, rectifier. DETAILED DESCRIPTION

[0067] The present application is further described below in conjunction with the drawings and embodiments.

[0068] Embodiment:

[0069] In the conventional starting mode of such mobile ice melting device, the terminal voltage of the generator is rated voltage when the no-load transformer is put into operation. Due to the influence of the nonlinearity of the transformer core and the hysteresis effect, there is often an excitation inrush current when the transformer is put into operation. When the excitation inrush current exceeds a certain value, it is easy to cause the protection action of the transformer or the generator, so that the generator is taken out of operation, resulting in failure of power supply. In the related art, the excitation inrush current problem of the transformer is mostly suppressed by core demagnetization technology and phase selection closing technology.

[0070] However, the demagnetization technology has complex wiring, and the whole demagnetization process is time-consuming and laborious. The mobile ice melting device requires the characteristics of convenience and rapidity, and the core demagnetization technology is difficult to be applied in the mobile ice melting project.

[0071] And the control of the phase selection closing technology is more complex, which needs to fully master the magnetization history of the core, and is more suitable for substations with long-term unchanged transformer and power characteristics. For the mobile ice melting device, due to the various combination forms of the mobile generator car and the mobile transformer, and the mobile transformer is only used when the line is iced in winter, it is difficult to accurately master the magnetization history of the core, and such phase selection closing technology is also difficult to apply in the mobile ice melting project.

[0072] Based on this, the embodiment proposes a starting control method of the mobile ice melting device, as shown in Figure 1 , which comprises:

[0073] Starting the power supply device, establishing the connection between the mobile ice melting device and the power supply equipment when the generator of the power supply device reaches the predetermined condition, and putting in the no-load transformer;

[0074] Starting the excitation regulation device, and collecting the generator speed of the power supply device in real time;

[0075] Based on the generator speed of the power supply device, the excitation regulation input strategy is constructed in combination with the starting time;

[0076] The excitation regulation device adjusts the output voltage of the power supply device in response to the input strategy;

[0077] When the output voltage of the power supply device reaches the rated voltage, the connection between the mobile ice melting device and the ice melting line is established.

[0078] Considering that the excitation current of the no-load transformer when put in can be decomposed into two parts of transient excitation current and steady-state excitation current, the transient excitation current is the main component of the excitation inrush current, and the steady-state component of the excitation current is very small, generally not more than 1% of the rated current of the transformer. And due to the existence of transformer loss, including hysteresis loss and copper loss, the transient component of the excitation current is a decaying component, which will decay to 0 with the increase of time.

[0079] Therefore, by controlling the generator excitation current and further controlling the change law of the generator terminal voltage, the speed of reducing the transformer terminal voltage and the time of increasing the terminal voltage are realized, the hysteresis loss and copper loss of the transformer are fully utilized, the growth speed of the transformer excitation current is adapted to the decay speed, so as to effectively suppress the excitation inrush current of the transformer in the starting process of the mobile ice melting device. And by the way of putting in the excitation regulator in stages, the change characteristics of the excitation inrush current when the no-load transformer is put in are targetedly responded, and the precise suppression of the excitation inrush current is realized in all directions.

[0080] For the initial start, after starting the power supply device, the connection between the mobile ice melting device and the power supply equipment is not established immediately, but waits for the generator to reach the predetermined condition, and then establishes the connection to put the no-load transformer into operation, to avoid the impact in the unstable state from the source.

[0081] Specifically, the start power supply device establishes the connection between the mobile ice melting device and the power supply equipment when the generator of the power supply device reaches the predetermined condition, comprising:

[0082] The start power supply device puts the prime mover and the speed regulator of the power supply device into operation;

[0083] Powered by the prime mover, the speed of the generator is raised according to the speed regulator;

[0084] When the speed of the generator is raised to the rated speed, the connection between the mobile ice melting device and the power supply equipment is established.

[0085] The prime mover serves as the power source for the generator, providing energy for the operation of the generator, and its performance directly affects whether the generator can stably output power. The core function of the speed regulator is to dynamically adjust the output power of the prime mover according to the set target speed, i.e. the rated speed of the generator. When the start power supply device is started, the prime mover begins to operate, at which time the speed regulator will monitor the current speed of the generator in real time and compare it with the rated speed. If the current speed is lower than the rated speed, the speed regulator will increase the fuel supply of the prime mover, such as increasing the oil supply or adjusting the air intake of the diesel generator, to make the prime mover output more power and drive the generator speed up. When the speed approaches the rated speed, the speed regulator will make fine adjustments to avoid large overshoot of the speed and ensure that the speed stabilizes at the rated value.

[0086] Considering that the output voltage and frequency of the generator are closely related to the speed, when the speed has not reached the rated value, the output voltage and frequency are unstable. At this time, if the load, i.e. the no-load transformer, is connected, it will cause further fluctuations in voltage and frequency, which not only may damage the load equipment, but also will cause a large impact on the generator itself, affecting its service life.

[0087] Therefore, when the speed of the generator is raised to the rated speed, the connection between the mobile ice melting device and the power supply equipment is established again to put the no-load transformer into operation, so as to minimize the impact on the mobile ice melting device.

[0088] This way of establishing the connection after stabilizing the speed of the generator at the rated speed by the speed regulator ensures that the no-load transformer is put into operation after the voltage and frequency output by the generator are in a stable state, avoiding abnormal impact on the transformer caused by unstable voltage and frequency due to speed fluctuations, reducing additional losses of the transformer due to unstable voltage, prolonging the service life of the transformer, and ensuring the quality of electrical energy at the initial connection.

[0089] The excitation regulating device can more accurately judge the operation state of the generator when collecting the generator speed, so as to more accurately construct the excitation regulating input strategy, and provide more accurate data support for inhibiting the excitation inrush current when the no-load transformer is input and stabilizing the generator output voltage.

[0090] The generation and duration of the excitation inrush current are directly affected by the dynamic operation state of the generator, and the speed is a core parameter reflecting the dynamic characteristics of the generator. The speed of the generator affects the synchronous reactance, transient potential and other parameters of the generator, resulting in differences in the amplitude and decay rate of the excitation inrush current.

[0091] The start-up time is a key parameter for dividing the inrush active period and stable operation period after the no-load transformer is input. A certain period of time after the no-load transformer is input is the excitation inrush active period, and the inrush peak value will concentrate. After the excitation inrush active period, the inrush gradually decays to the stable excitation current, and enters the stable operation period of the conventional load state. The two stages have completely different demands for excitation regulation. In the active period, a strong response and high compensation regulation strategy is needed, and in the stable period, a fine regulation focusing on voltage accuracy is needed.

[0092] Therefore, considering the two key parameters affecting the excitation inrush current, a specific excitation regulating input strategy is established.

[0093] Specifically, the generator speed based on the power supply device is combined with the start-up time to construct the excitation regulating input strategy, which comprises:

[0094] When the generator speed is equal to the rated speed and the current time is less than the start-up time of the power supply device, a start-up excitation regulator is selected to be input, and a voltage control strategy is constructed in combination with the start-up time and the output voltage at the generator end.

[0095] When the current time is greater than or equal to the start-up time of the power supply device, an excitation regulator is selected to be input, and a voltage control strategy is constructed according to the output voltage at the generator end.

[0096] The generator speed and the start-up time are used to distinguish the excitation inrush active period and the stable operation period, and then different excitation regulators are used for corresponding voltage control.

[0097] When the generator speed is equal to the rated speed and the current time is less than the start-up time of the power supply device, it can be determined that the current is in the excitation inrush active period. At this time, the peak effect of the excitation inrush current is significant, and the inrush current characteristics are affected by the start-up time. The regulation by simply using voltage feedback has a lag, therefore, a start-up excitation regulator is input, and corresponding voltage control is realized in combination with the start-up time and the output voltage at the generator end, so as to actively inhibit the inrush current.

[0098] When the current time is greater than or equal to the starting time of the power supply device, it can be judged that the stable operation period has been entered, at this time, the load characteristics tend to be stable, and the voltage fluctuation is mainly caused by the change of the conventional load, without complex time prediction, the corresponding voltage control can be realized by collecting the output voltage of the generator end in real time through the excitation regulator.

[0099] The starting time of the power supply device is a preset value, which can be set according to the actual situation.

[0100] For the voltage control in the active period of the excitation inrush current, the starting excitation regulator is selected to be put into operation, and the starting time and the output voltage of the generator end are combined to construct a voltage control strategy, including:

[0101] The starting excitation regulator generates an excitation voltage control signal according to the starting time;

[0102] The voltage difference between the excitation voltage control signal and the output voltage of the generator end is calculated, and the adjustment signal is output according to the calculation result of the voltage difference and the PID control output;

[0103] The excitation current is output based on the adjustment signal, and the output voltage of the generator end is adjusted according to the excitation current.

[0104] The main function of the starting excitation regulator is to increase the excitation voltage of the generator from 0 to 80% of the rated excitation voltage in a linear manner between the time when the generator speed is raised to the rated speed and the starting time of the power supply device.

[0105] The control logic of the starting excitation regulator is specifically as shown in Figure 2 . Figure 2 Among them, the inrush current elimination controller is used to generate an excitation voltage control signal F(t) according to the starting time, K is a proportional amplifier, V g is the output voltage of the generator end, I f is the excitation current of the generator, G is the generator, E f is the adjustment signal of the PID control output excitation voltage.

[0106] During the starting period of the generator, the inrush current elimination controller generates an excitation voltage control signal F(t) through a corresponding control function, and the expression of the control function is:

[0107]

[0108] Where, t is the current starting time, t0 is the time when the generator speed rises to the rated speed, t s is the starting time of the generator.

[0109] Then, the difference e between the excitation voltage control signal F(t) and the output voltage of the generator end is calculated, where e=F(t)-V gand the difference e is amplified K times as the input signal of the PID control.

[0110] The corresponding parameters in the PID control can be set according to requirements. In the embodiment, the parameters of the PID control are specifically set as follows: K p = 0.2, K i = 20, K d = 0. Through the PID control, an adjustment signal E f of the excitation voltage can be output.

[0111] Further, through a power adjustment unit such as a power regulator, an excitation current I f is output to the excitation winding of the generator according to the adjustment signal E f , and then the output voltage V f at the generator end is adjusted according to the excitation current I g .

[0112] Through the synergistic effect of the start-up time prediction and the real-time correction of the PID, the preliminary adjustment of the excitation current can be completed before the peak of the inrush current appears, the loss of magnetic flux caused by the excitation inrush current is compensated, and it is ensured that the output voltage at the generator end can be pulled back to the target range, that is, the situation that the protection action is triggered due to the voltage being too low can be avoided, and the impact of the voltage fluctuation on the transformer and the generator can be reduced.

[0113] And due to the advance increase of the excitation voltage, the support of the output voltage at the generator end is enhanced, which indirectly weakens the saturation degree of the transformer core, effectively reduces the peak value and duration of the excitation inrush current, further reduces the thermal shock on the generator winding, and ensures the operation safety of the mobile ice melting device.

[0114] The core feature of the stable operation period is that the excitation inrush current has been greatly attenuated, the load characteristics tend to be stable, the mobile ice melting device is mainly used as a conventional resistive or inductive load, and the voltage fluctuation of the output voltage at the generator end is mainly caused by slight load changes. Therefore, the voltage control strategy in this stage mainly focuses on fine voltage stabilization and low-loss regulation. In the embodiment, the excitation regulator invested for the stable operation period is the excitation regulator of the generator. When the output voltage at the generator end approaches the rated voltage, the excitation control right of the generator is taken over, and the excitation voltage of the generator is further adjusted according to the set PID control.

[0115] Specifically, the excitation regulator is selected and invested, and a voltage control strategy is constructed according to the output voltage at the generator end, including:

[0116] The output voltage at the generator end is collected in real time, and the rated voltage of the generator is combined to output an excitation current adjustment signal through PID control;

[0117] The excitation current is output based on the excitation current adjustment signal, and the output voltage at the generator end is adjusted according to the excitation current.

[0118] The parameter setting of the PID control in the excitation regulator is different from that in the starting excitation regulator. For the characteristics of the stable running period, the load fluctuation is gentle, and the voltage deviation is small. A mode with a low proportional coefficient and a high integral coefficient is adopted. The proportional coefficient of the PID control in the excitation regulator is set to 60% of the proportional coefficient of the PID control in the starting excitation regulator, and the integral coefficient of the PID control in the excitation regulator is set to 1.5 times of the integral coefficient of the PID control in the starting excitation regulator.

[0119] The PID control in the above excitation inrush active period and stable running period adopts the existing PID control logic, and the control process of the PID control is not described again.

[0120] Specifically, the overall flowchart of the generator excitation control in the starting process of the mobile ice melting device is as shown in Figure 3 . Figure 3 Among them, ω g is the generator speed, and ω gR is the rated speed of the generator.

[0121] Considering that the mobile ice melting device is connected with the ice melting line and put into ice melting work, the adjustment of the output voltage is still realized through the excitation regulator, and the transition of the ice body from solid state to liquid state in the ice melting process will cause significant changes in the load characteristics, such as the decrease of the resistance value with the increase of the temperature and the stage fluctuation of the power. If the fixed voltage control strategy is directly used, it is difficult to adapt to the load demand in different ice melting stages.

[0122] For example, in the initial ice melting stage, the ice body is hard, and the load characteristics are large load resistance and stable power demand. In the middle stage of rapid ice melting, the ice body is largely melted, and the load characteristics are sudden resistance drop and power surge. In the later stage of heat preservation, the ice body is basically melted, and the load characteristics are power tending to be flat. This load characteristic change trend may cause voltage drop due to the adjustment lag of the voltage control strategy when the power surges, or cause energy waste due to excessive adjustment when the power is flat.

[0123] Therefore, in order to avoid the influence of the voltage control strategy of the excitation regulator in the starting process on the ice melting work of the mobile ice melting device, the voltage control strategy is further dynamically adjusted according to the ice melting progress, so as to balance the stability of power supply and the efficiency of ice melting.

[0124] Specifically, after establishing the connection between the mobile ice-melting device and the ice-melting line, the output voltage of the generator is adjusted according to the excitation regulator, and the voltage control strategy of the excitation regulator is adjusted according to the ice-melting progress of the mobile ice-melting device.

[0125] The voltage control strategy of the excitation regulator is adjusted according to the ice-melting progress of the mobile ice-melting device, and includes:

[0126] Based on historical ice-melting information, ice-melting stages are divided, and load characteristics of each ice-melting stage are obtained.

[0127] Real-time operation information of the current mobile ice-melting device is collected, and the current ice-melting stage in which the current ice-melting progress is located is identified in combination with the load characteristics.

[0128] The voltage control target is set according to the ice-melting stage, and the PID control parameter and the feedforward compensation parameter are adjusted, and the corresponding voltage control strategy is constructed according to the output voltage at the generator end.

[0129] According to the historical ice-melting information such as ice-melting time, power curve, and resistance change under different environmental temperatures and ice thickness, the historical ice-melting information is clustered through a clustering algorithm such as K-means, and the whole ice-melting process is divided into several ice-melting stages such as ice-melting early stage, ice-melting middle stage, and ice-melting late stage according to the clustering results, and the load characteristics of each ice-melting stage are determined.

[0130] During the ice-melting process, real-time operation information of the mobile ice-melting device such as current running time, output power, heating element temperature, and line current is collected, and the corresponding feature vector is constructed, and then the feature vector is compared with the load characteristics of each ice-melting stage through a similarity algorithm such as cosine similarity to identify the ice-melting stage in which the current ice-melting progress is located.

[0131] Based on the corresponding ice-melting stage, the mapping relationship between the preset ice-melting stage and the parameter setting is called to set the corresponding voltage control target.

[0132] For the ice-melting early stage, the load is mainly stable resistance, the power fluctuation is small, and the voltage can have slight fluctuation, so the voltage control target can be set as ±3% of the rated voltage of the generator, which avoids the increase of energy consumption caused by excessive regulation and reserves the regulation margin for the subsequent stage.

[0133] For the ice-melting middle stage, the load resistance drops suddenly, the power increases suddenly, and the impact current is accompanied, so the voltage drop needs to be suppressed first, and therefore the voltage control target can be set as ±2% of the rated voltage of the generator, which tightens the control range to ensure sufficient heating power and avoid the decrease of ice-melting speed caused by too low voltage.

[0134] For the late stage of ice melting, due to its stable load resistance and gentle power, high-precision voltage stabilization is required to avoid local overheating, therefore, the voltage control target can be set to the rated voltage of the generator ±1%, to ensure uniform temperature in the insulation stage and prevent secondary freezing of the ice body or overheating damage to the equipment.

[0135] According to the voltage response requirements of each stage, the PID control parameters and feedforward compensation parameters are adjusted based on the preset parameter combination.

[0136] For example, in the middle stage of ice melting, for the PID control parameters, the proportional coefficient is increased to accelerate the response to power surge, the differential coefficient is increased to predict the voltage drop trend, and the integral coefficient is fine-tuned to avoid steady-state deviation. For the feedforward compensation parameters, power rise feedforward is enabled, and when the power rise rate is greater than the preset threshold, a fixed amount of excitation current compensation is immediately output to support the voltage in advance and offset the drop caused by the impact.

[0137] After setting the relevant parameters, the corresponding voltage control strategy can be constructed based on the current output voltage of the generator through PID control and feedforward compensation to achieve the corresponding voltage control adjustment.

[0138] The environmental information of the ice melting scene, such as sudden drop in ambient temperature, sudden increase in wind speed causing abnormal ice accumulation speed, and device operation information, such as short circuit of heating elements, sensor failure causing power or temperature data distortion, may cause the real-time feature vector to deviate from the true ice melting stage benchmark.

[0139] For example, a sudden drop in ambient temperature of 10°C will slow down the melting speed of the ice body, and the ice melting progress that should be in the middle stage will actually stagnate, but the power, resistance, and other data may show similar characteristics of the late stage due to temperature effects. If the anomaly is not identified, the stage identification will be misjudged as the late stage, and the wrong PID control parameters and feedforward compensation parameters will be called, causing the voltage control strategy to deviate from the actual load demand.

[0140] Therefore, during the operation of the mobile ice melting device, the following is also performed:

[0141] Real-time collection of environmental information of the ice melting scene and operation information of the mobile ice melting device to identify abnormal working conditions of the mobile ice melting device;

[0142] When an abnormal working condition is identified, the ice melting stage identification is reset.

[0143] When an abnormal working condition is identified, the stage identification is immediately reset, the current parameter configuration is suspended, and the preset universal parameter combination and relaxed voltage control target are used to perform subsequent ice melting work. After the abnormality is resolved, the stage is re-identified based on the real data, and the voltage control strategy is adjusted to reduce the risk of damage to the mobile ice melting device.

[0144] For example,Figure 4 Another aspect of the embodiment also provides a start control system of the mobile ice-melting device, comprising:

[0145] A power supply device 1 is configured to supply power to the mobile ice-melting device;

[0146] An excitation adjustment device 2 is connected to the power supply device and configured to formulate an input strategy of an excitation regulator according to the generator speed and the start time of the power supply device and adjust the output voltage of the power supply device correspondingly;

[0147] The control switch 3 comprises at least a first control switch 31 and a second control switch 32,

[0148] The first control switch is arranged between the power supply device and the mobile ice-melting device and configured to establish the connection between the mobile ice-melting device and the power supply device when the generator of the power supply device meets a predetermined condition;

[0149] The second control switch is arranged between the mobile ice-melting device and the ice-melting circuit and configured to establish the connection between the mobile ice-melting device and the ice-melting circuit when the output voltage of the power supply device reaches a rated voltage.

[0150] The power supply device in the embodiment is a power supply device with a mobile function, such as a power generation vehicle, which can realize mobile power supply. The power supply device is provided with a prime mover 11, a generator 12 and a speed regulator 13. After the power supply device is started, the prime mover is powered, and the speed of the generator is raised to the rated speed through the speed regulator.

[0151] The excitation adjustment device comprises:

[0152] A start excitation regulator 21 is connected to the power supply device and configured to adjust the voltage according to the start time and the output voltage at the generator end of the power supply device;

[0153] An excitation regulator 22 is connected to the power supply device and configured to adjust the voltage according to the output voltage at the generator end;

[0154] A selection unit 23 is connected to the excitation regulator and the start excitation regulator and configured to select the excitation regulator or the start excitation regulator to perform voltage adjustment according to the generator speed and the start time of the power supply device.

[0155] The selection unit comprises a microprocessor and corresponding sensors, which are arranged on the generator of the power supply device and can collect the rotation speed and start time of the generator. When the rotation speed of the generator is less than the rated rotation speed, the output value is 0, and no excitation regulator is selected. When the rotation speed of the generator is equal to the rated rotation speed and the current time is less than the start time of the power supply device, the output value is 1, and the start excitation regulator is selected for voltage control. When the current time is greater than or equal to the start time of the power supply device, the output value is -1, and the excitation regulator is selected for voltage control.

[0156] The excitation regulator is a common exciter relying on PID control, which comprises a corresponding PID controller and a power converter, and can output a corresponding adjustment signal in real time according to the output voltage.

[0157] The start excitation regulator further comprises a surge current elimination controller and a proportional amplifier in addition to the PID controller and the power converter. The surge current elimination controller has a control function for generating an excitation voltage control signal according to the start time. After the excitation voltage control signal is amplified by the proportional amplifier, the corresponding voltage control can be performed according to the corresponding PID controller.

[0158] The first control switch and the second control switch are circuit breakers. After the first control switch is closed, the transformer 4 in the idle state is put into operation. After the second control switch is closed, the ice melting line 5 is connected, and then the filter 6 and the rectifier 7 are put into operation, so that the start of the mobile ice melting device is completed, and the ice melting work is carried out.

[0159] Taking the start process of one of the mobile DC ground wire ice melting devices as an example, the time t0 required for the rotation speed of the generator to rise from 0 to the rated rotation speed is 5s, and the time t1 required for the terminal voltage of the generator to rise from 0 to the rated voltage is 60s. s

[0160] According to the start control method provided in the embodiment, the terminal voltage of the generator rises from 0 to the rated voltage during the start of the power supply device. The voltage change curve and the voltage change waveform of the generator during the start process are shown in Figure 5 and Figure 6 respectively. In the late start process, the voltage change curve of the generator in the steady state is shown in Figure 7 .

[0161] As shown in Figure 5 , Figure 6 and Figure 7 , the voltage of the transformer rises from 0 to the rated voltage during the start process of the DC ice melting device.

[0162] ​After reaching the predetermined condition, the no-load transformer is put into operation, the terminal voltage of the transformer is equal to the output voltage of the generator, thus the voltage of the primary side of the transformer gradually increases from 0 to the rated voltage, and the magnetic flux of the transformer core is also a process of increasing vibration, the magnetic flux change of the transformer core in the initial stage of starting is shown in Figure 8 , the magnetic flux change in the late stage of starting and the magnetic hysteresis loop of the transformer core are shown in Figure 9 and Figure 10 , respectively. Figure 11 and Figure 12 .

[0163] As can be seen from Figure 9 , Figure 10 , Figure 11 and Figure 12 , at the initial moment of transformer input, the magnetic flux of the transformer core fluctuates around the residual magnetism, and the magnetic flux is not symmetrical, and with the increase of time, although the whole amplitude of the magnetic flux gradually increases, the magnetic flux gradually tends to be symmetrical, and the symmetrical change of the magnetic flux can effectively suppress the excitation inrush current.

[0164] During the starting process, the excitation current of the transformer is also a process of increasing vibration with time, but during the whole starting process, the transformer excitation current is very small, the maximum value of the transformer excitation current during the starting process is equivalent to the rated excitation current, the excitation current change during the starting process, the transformer current waveform at the initial stage of starting, and the transformer current waveform in the late stage of starting are shown in Figure 13 , Figure 14 and Figure 15 , respectively.

[0165] The starting control of the mobile DC ground ice melting device with the same parameter setting as the traditional starting method is executed, and the transformer excitation inrush current waveform during the starting process is shown in Figure 16 .

[0166] As can be seen from Figure 13 , Figure 14 , Figure 15 and Figure 16 , through the starting control method of the embodiment, the excitation current of the transformer can be maintained at not more than 1A, and the influence of the excitation inrush current can be completely eliminated.

[0167] Therefore, in combination with Figures 5-15It can be seen that with the increase of the generator speed, the terminal voltage of the generator is oscillated from 0 to the rated voltage, the hysteresis loop of the transformer core is oscillated around the residual magnetism in the initial stage of starting, the center of the hysteresis loop is gradually shifted to the 0 residual magnetism point, and the oscillation range of the hysteresis loop is gradually increased, but it is basically in the linear region of the hysteresis loop, and the excitation current of the transformer is always less than 1A in the starting process, so the excitation inrush current when the no-load transformer is put into operation is effectively eliminated.

[0168] The above-described embodiments are only a preferred scheme of the present application, and do not limit the present application in any form, and other variants and modifications are possible without departing from the technical scheme recited in the claims.

Claims

1. A start-up control method for a mobile ice-melting device, characterized in that, include: Start the power supply device, and when the generator of the power supply device reaches the predetermined conditions, establish the connection between the mobile ice melting device and the power supply equipment, and put the unloaded transformer into operation. Start the excitation regulator and collect the generator speed of the power supply unit in real time; Based on the generator speed of the power supply unit and the start-up time, an excitation regulation input strategy is constructed. The excitation regulating device adjusts the output voltage of the power supply device in response to the activation strategy. When the output voltage of the power supply device reaches the rated voltage, establish the connection between the mobile de-icing device and the de-icing line.

2. The start-up control method for the mobile ice-melting device according to claim 1, characterized in that, The excitation regulation activation strategy, based on the generator speed of the power supply unit and the start-up time, includes: When the generator speed is equal to the rated speed and the current time is less than the start-up time of the power supply unit, the starting excitation regulator is selected to be engaged. A voltage control strategy is constructed by combining the start-up time and the output voltage at the generator terminal. When the current time is greater than or equal to the start-up time of the power supply unit, the excitation regulator is selected to be engaged, and a voltage control strategy is constructed based on the output voltage at the generator terminal.

3. The start-up control method for the mobile ice-melting device according to claim 2, characterized in that, The selection of the starting excitation regulator, combined with the starting time and the output voltage at the generator terminals, constructs a voltage control strategy, including: The excitation regulator generates an excitation voltage control signal based on the startup time. Calculate the voltage difference between the excitation voltage control signal and the generator terminal output voltage, and based on the voltage difference calculation result, combine it with PID control to output adjustment signal; Based on the adjustment signal output excitation current, the output voltage at the generator terminal is adjusted according to the excitation current.

4. The start-up control method for the mobile ice-melting device according to claim 2, characterized in that, The selection of the excitation regulator and the construction of a voltage control strategy based on the generator terminal output voltage include: The generator output voltage is collected in real time, and combined with the generator's rated voltage, the excitation current adjustment signal is output through PID control. The excitation current is adjusted based on the excitation current adjustment signal, and the output voltage at the generator terminals is adjusted according to the excitation current.

5. The start-up control method for the mobile ice-melting device according to claim 1, characterized in that, Also includes: After establishing the connection between the mobile de-icing device and the de-icing line, the generator output voltage is adjusted according to the excitation regulator, and the voltage control strategy of the excitation regulator is adjusted according to the de-icing progress of the mobile de-icing device.

6. The start-up control method for the mobile ice-melting device according to claim 5, characterized in that, The method of adjusting the voltage control strategy of the excitation regulator according to the melting progress of the mobile ice-melting device includes: The ice-melting stages are divided based on historical ice-melting information, and the load characteristics of each ice-melting stage are obtained. Real-time collection of operational information of the current mobile ice-melting device, combined with load characteristics to identify the current ice-melting stage; The voltage control target is set according to the ice melting stage, and the PID control parameters and feedforward compensation parameters are adjusted. A corresponding voltage control strategy is constructed based on the output voltage at the generator end.

7. The start-up control method for the mobile ice-melting device according to claim 6, characterized in that, Also includes: Real-time collection of environmental information from the ice-melting scene and operational information from the mobile ice-melting device, and identification of abnormal operating conditions of the mobile ice-melting device; When an abnormal operating condition is detected, the ice melting stage identification is reset.

8. The start-up control method for the mobile ice-melting device according to claim 1, characterized in that, The aforementioned power supply device, when its generator reaches predetermined conditions, establishes a connection between the mobile ice-melting device and the power supply equipment, including: Start the power supply unit and connect the prime mover and speed controller of the power supply unit; Powered by the prime mover, the generator speed is increased by the speed governor; Once the generator speed reaches the rated speed, establish a connection between the mobile de-icing device and the power supply equipment.

9. A start-up control system for a mobile ice-melting device, used to execute the start-up control method according to any one of claims 1 to 8, characterized in that, include: Power supply unit, used to supply power to the mobile ice-melting device; The excitation regulator is connected to the power supply unit and is used to formulate the activation strategy of the excitation regulator according to the generator speed and start-up time of the power supply unit, and adjust the output voltage of the power supply unit accordingly. A control switch that includes at least a first control switch and a second control switch. The first control switch is set between the power supply unit and the mobile ice-melting device, and is used to establish a connection between the mobile ice-melting device and the power supply unit when the generator of the power supply unit meets the predetermined conditions. The second control switch is installed between the mobile ice-melting device and the ice-melting line, and is used to establish the connection between the mobile ice-melting device and the ice-melting line when the output voltage of the power supply device reaches the rated voltage.

10. The start-up control system of the mobile ice-melting device according to claim 9, characterized in that, The excitation regulating device includes: Start the excitation regulator, connect it to the power supply unit, and use it to adjust the voltage according to the start-up time of the power supply unit and the output voltage at the generator end; The excitation regulator, connected to the power supply unit, is used to adjust the voltage according to the output voltage at the generator terminal; the selection unit, connected to the excitation regulator and the starting excitation regulator, is used to select whether to engage the excitation regulator or start the excitation regulator to perform voltage adjustment according to the generator speed and start-up time of the power supply unit.

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