A closed-loop variable period control algorithm for power control power supply

Abstract

The application provides a closed-loop variable period control algorithm of a power control power supply, and relates to the technical field of power control power regulation. The zero-crossing signal of the collected AC power is converted into a PWM wave signal, the power regulation ratio is calculated by collecting the power regulation signal, the expected output power of the power control power supply is calculated according to the power regulation ratio and the rated power of the power control power supply, the single-cycle power is calculated according to the real-time output current value and voltage value of the power control power supply, the frequency of the regulation expected power that needs to be turned on in the cycle time is calculated according to the expected output power and the single-cycle power, the length of the regulation small cycle in the cycle time and the number of cycles in the small cycle are calculated, the cycles are evenly distributed in the cycle time, the rising edge signal of the PWM wave signal is controlled according to the cycle distribution, and the controller module controls the opening and closing of the thyristor to control the output of the cycle, so that the output of the power control power supply is adjusted.

Description

Technical Field

[0001] The present invention relates to the technical field of power regulation of a control power supply, and in particular to a closed-loop variable-cycle control algorithm for a power control power supply. Background Art

[0002] Power control power supplies are widely used in heating applications in industrial furnaces, mechanical equipment, the glass industry, the automotive industry, the chemical industry, and other industries. They need to strictly distribute power to each load location without large temperature differences. This requires that under different power adjustment ratios, the output power can quickly reach the desired level and the frequency distribution can be evenly distributed, so that different output power ranges can be determined according to different adjustment signals.

[0003] In the prior art, publication number CN101662153A discloses a thyristor power control triggering method, which controls the number of on-state cycles and off-state cycles within a control period T during load power regulation, and controls an angle a on the on-state cycles within the period T.

[0004] However, although this method is adjusted through the frequency and frequency angle, it does not output the frequency at zero point. The output is a non-shaped wave, which may produce large instantaneous voltage and current spikes, causing the circuit to have no overshoot and oscillation. At the same time, there is a lack of feedback signal. The system is prone to become unstable or oscillate when there is external interference or load changes. Therefore, there is an urgent need for a closed-loop variable-cycle control algorithm for a power control power supply with closed-loop regulation and periodic power control to make the power output more balanced and without oscillation.

[0005] The above information disclosed in this Background section is only for enhancement of understanding of the background of the present disclosure and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art. Summary of the Invention

[0006] The object of the present invention is to provide a closed-loop variable-cycle control algorithm for a power control power supply to solve the problems raised in the above background technology.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A closed-loop variable-cycle control algorithm for a power control power supply, comprising the following steps:

[0009] Step 1: Connect the power supply to be controlled to the voltage stabilizer and the filter in sequence to obtain a stable power supply to be controlled. Collect the zero-crossing signal of each phase of the three-phase AC power of the power supply to be controlled, and convert the positive half-wave of the AC sine wave into a high-level pulse signal and the negative half-wave into a low-level pulse signal (PWM wave signal), and send it to the controller module;

[0010] Step 2: By inputting a power regulation signal into the acquisition end of the power regulation sampling circuit, a power regulation ratio between the power regulation signal and the sampling signal range of the sampling circuit is calculated. Based on the power regulation ratio and the rated power of the control power supply, the expected output power of the power supply to be controlled is calculated;

[0011] Step 3: By collecting the real-time current and voltage signals of the output end of the control power supply and pre-processing the collected real-time current and voltage signals, the effective value of the phase voltage and the effective value of the phase current of each phase are calculated, and the single-cycle power of the output power supply is calculated based on the effective values ​​of the voltage and current;

[0012] Step 4: Set the adjustment accuracy value for the expected output power. Based on the expected output power and the single-cycle power, calculate the number of cycles that need to be turned on within the cycle time. Based on the number of cycles, calculate the length of the small adjustment cycle within the cycle time and the number of cycles in the small cycle according to the variable cycle algorithm.

[0013] Step 5: Based on the small cycle and the number of cycles within the small cycle, the cycles are evenly distributed within the cycle time through calculation. Based on the cycle distribution and the rising edge signal of the PWM wave signal, the controller module adjusts the power of the control power supply by controlling the output of the control cycle by controlling the opening and closing of the thyristor.

[0014] In this embodiment, the calculation formula of the power adjustment ratio is:

[0015]

[0016] Among them, R is the power regulation ratio, and Y is the power regulation signal input from the acquisition end;

[0017] The calculation formula for the expected power of the power supply to be controlled is:

[0018] P exp =P*R

[0019] Among them, P exp is the expected power, P is the rated power, and R is the power regulation ratio.

[0020] In this embodiment, the specific steps of preprocessing the collected real-time current and voltage signals and calculating the effective value of the phase voltage and the effective value of the phase current of each phase are:

[0021] Data is collected every 0.001ms. After collecting data 200 times, the effective value of the data is calculated. The specific calculation formula is:

[0022]

[0023] Among them, a rmsis the effective value of voltage and current signal, a n is the data collected for the nth time, where n is a positive integer, n=1, 2…200;

[0024] The calculation formula for the output power of the power supply to be controlled is:

[0025]

[0026] Among them, P sin is the output power, C A , C B , C C are the current values ​​in the three-phase AC phase A, phase B, and phase C circuits, U AB , U BC They are the line voltage between phase A and phase B, and the line voltage between phase B and phase C in the three-phase AC phase A, phase B, and phase C circuits respectively.

[0027] In this embodiment, the calculation formulas for the line voltage between phase A and phase B and the line voltage between phase B and phase C are:

[0028]

[0029]

[0030] Among them, U AB U is the line voltage between phase A and phase B in the three-phase AC circuit. BC U is the line voltage between phase B and phase C in the three-phase AC A, B, and C circuits. A is the line voltage of phase A, U B is the line voltage of phase B, U C is the line voltage of phase C.

[0031] In this embodiment, the calculation formula for calculating the time length of the small adjustment cycle within the cycle time and the number of cycles in the small cycle according to the variable cycle algorithm is:

[0032]

[0033] Among them, X is the frequency that needs to be turned on, T is the adjustment period, P sin is the output power, P exp is the expected power, t is a single cycle;

[0034] The calculation formula for calculating the time length of the small cycle within the cycle time and the number of cycles in the small cycle is:

[0035]

[0036]

[0037] Among them, M is the time length of the small cycle, q is the adjustment accuracy value, and N is the number of cycles in the small cycle.

[0038] In this embodiment, the specific logic for evenly distributing the cycles within the period time is as follows:

[0039]

[0040] When N>X-N, first cycle M+1 and M small cycles alternately for X-N times, then cycle M+1 small cycles for X-2N times;

[0041] When N <X―N,先N次交替循环M+1和M小周期,再循环X―2N次M小周期。

[0042] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention converts the collected zero-crossing signal of the alternating current into a PWM wave signal, collects the power regulation signal, calculates the power regulation ratio, calculates the output expected power of the power supply to be controlled based on the power regulation ratio and in combination with the rated power of the control power supply, calculates the single-cycle power based on the real-time output current value and voltage value of the control power supply, calculates the number of cycles that need to be turned on within the cycle time to adjust the expected power, as well as the time length of the small cycle adjusted within the cycle time and the number of cycles within the small cycle, so that the cycles are evenly distributed within the cycle time, and according to the cycle distribution and the rising edge signal of the PWM wave signal, the controller module controls the output of the control cycle by controlling the opening and closing of the thyristor, thereby adjusting the output power of the control power supply.

[0043] The present invention performs feedback based on the output voltage and current signals to form a closed-loop control, and at the same time adopts a variable period algorithm to distribute the cycles required to be output as evenly as possible within the cycle time, so that the power output is more balanced. At the same time, each cycle is adjusted and output at zero point to prevent voltage overshoot and oscillation. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 Schematic diagram of the overall method flow of the present invention;

[0045] Figure 2 This is a schematic diagram of the zero-crossing detection circuit of the present invention;

[0046] Figure 3 The zero-crossing detection circuit of the present invention has an input and output waveform diagram;

[0047] Figure 4 This is a circuit diagram of a power regulation signal sampling circuit according to the present invention;

[0048] Figure 5This is a power output waveform diagram of the variable period algorithm of the present invention;

[0049] Figure 6 This is a flow chart of the variable period algorithm of the present invention. DETAILED DESCRIPTION

[0050] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to specific embodiments.

[0051] It should be noted that, unless otherwise defined, the technical or scientific terms used in the present invention should have the usual meanings understood by people with ordinary skills in the field to which the present invention belongs. The "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative position relationships. When the absolute position of the object being described changes, the relative position relationship may also change accordingly.

[0052] Example:

[0053] See also Figure 1-6 , the present invention provides a technical solution:

[0054] A closed-loop variable-cycle control algorithm for a power control power supply, comprising the following steps:

[0055] Step 1: Connect the power supply to be controlled to the voltage stabilizer and the filter in sequence to obtain a stable power supply to be controlled. Collect the zero-crossing signal of each phase of the three-phase AC power of the power supply to be controlled, and convert the positive half-wave of the AC sine wave into a high-level pulse signal and the negative half-wave into a low-level pulse signal (PWM wave signal), and send it to the controller module;

[0056] Voltage regulators help maintain the output voltage amplitude and waveform, ensuring it closely resembles an ideal sine wave. This is crucial for control power supplies, whose optimal performance relies heavily on the quality of the voltage waveform. They also help filter or suppress harmonic interference in the power grid, improving overall power quality and protecting downstream equipment from suboptimal power quality. Harmonics are frequency components above the fundamental frequency present in power supplies. They can be generated by nonlinear loads on the power grid, such as switching power supplies, LED lights, and electronic devices. Harmonics degrade the AC power waveform, impacting the efficiency and lifespan of the control power supply. Filters effectively remove these high-frequency harmonics, maintaining a sinusoidal waveform on the power line, ensuring stable power system operation while reducing electromagnetic interference. A zero-crossing detection circuit is an electronic circuit used to detect when the AC signal voltage crosses zero. The voltage is considered to have crossed zero when the AC voltage changes from positive to negative or vice versa. This is crucial for power regulation in control power supplies. Through the zero-crossing signal, the positive half-wave of the AC sine wave is converted into a high-level pulse signal, and the negative half-wave is converted into a PWM wave signal of a low-level pulse signal, and sent to the controller module. The continuous and periodic high and low levels form a PWM wave with a duty cycle of 50% and a frequency of 50Hz.

[0057] The zero-crossing signal of each phase of the three-phase alternating current of the controlled power supply is collected by a zero-crossing detection circuit, which is composed of a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a resistor R6, a resistor R7, a resistor R8, a resistor R9, a resistor R10, a resistor R11, a resistor R12, a resistor R13, a capacitor C1, a capacitor C2, a capacitor C3, a capacitor C4, a capacitor C5, a capacitor C6, an optocoupler 1, an optocoupler 2, an optocoupler 3, a VCC power supply terminal and a GND ground terminal. The resistor R1 is connected in series with the resistor R2, the resistor R4 is connected in series with the resistor R5, and the resistor R7 is connected in series with the resistor R8. The resistor R2 is connected in series with the resistor R8, one end of the resistor R2 is electrically connected to one end of the resistor R5, one end of the resistor R8, one end of the capacitor C1, one end of the capacitor C2, one end of the capacitor C3, the second input end of the optocoupler 1, the second input end of the optocoupler 2, and the second input end of the optocoupler 3, the other end of the resistor R2 is electrically connected to one end of the resistor R3 and the other end of the capacitor C1, the other end of the resistor R3 is electrically connected to the first input end of the optocoupler 1, the other end of the resistor R5 is electrically connected to one end of the resistor R6 and the other end of the capacitor C2, and the other end of the resistor R6 is electrically connected to the first input end of the optocoupler 2.

[0058] The other end of resistor R8 is electrically connected to one end of resistor R9 and the other end of capacitor C3, the other end of resistor R9 is electrically connected to the first input end of optocoupler 1, the VCC power supply end is electrically connected to one end of resistor R10, the other end of resistor R10 is electrically connected to the third input end of optocoupler 1, the third input end of optocoupler 2, the third input end of optocoupler 3, one end of resistor R11, one end of resistor R12, one end of resistor R13, one end of capacitor C4, one end of capacitor C5, and one end of capacitor C6, the fourth input end of optocoupler 1 is electrically connected to the fourth input end of optocoupler 2, the fourth input end of optocoupler 3, the other end of capacitor C4, the other end of capacitor C5, the other end of capacitor C6 and the GND grounding end, resistor R1, resistor R2, and resistor R3 are respectively connected to phase A, phase B, and phase C of the three-phase alternating current, resistor R11, resistor R12, and resistor R13 are connected to the input pin of the controller module, with phase A as the input pin. Taking the circuit as an example, after the voltage signal is divided by resistors R1 and R2, it is connected to the first input terminal of optocoupler 1. Resistors R2, R5 and R8 form a star connection. The voltage at the connection point is a neutral voltage, and the connection point is connected to the second input terminal of optocoupler 1. When the voltage in the A-phase circuit crosses zero in the positive direction, optocoupler 1 changes from the original on state to the off state, and the VCC power supply end outputs the value controller module through resistors R10 and R11. When the voltage in the A-phase circuit crosses zero in the reverse direction, optocoupler 1 changes from the original off state to the on state, and the VCC power supply end flows into the GND grounding end through resistor R10 and optocoupler 1. Resistor R11 does not output a signal, so the phase difference of the three-phase output signal is the same as the mains voltage, with a duty cycle of 50%, a frequency of 50Hz, and a phase difference of one-third of the cycle. Capacitors C1, C2 and C3 are voltage-stabilizing capacitors, and capacitors C4, C5 and C6 are filter capacitors.

[0059] The controller module adopts the main control chip model TMS320F28035, which is used for sampling, calculating, and generating driving signals. It can accurately perform closed-loop variable period algorithm and accurately control the pulse width of output PWM.

[0060] Step 2: By inputting a power regulation signal into the acquisition end of the power regulation sampling circuit, the power regulation ratio between the power regulation signal and the range of the sampling signal of the sampling circuit is calculated. Based on the power regulation ratio and the rated power of the control power supply, the expected output power of the power supply to be controlled is calculated.

[0061] Furthermore, the calculation formula of the power adjustment ratio is:

[0062]

[0063] Where R is the power regulation ratio, and Y is the power regulation signal input from the acquisition end;

[0064] The calculation formula for the expected power of the power supply to be controlled is:

[0065] P exp =P*R

[0066] Among them, P exp is the expected power, P is the rated power, and R is the power regulation ratio.

[0067] The power regulation ratio is used to adjust the output power of the control power supply. It is input through the acquisition end of the sampling circuit. The acquisition end of the sampling circuit inputs a 4-20mA analog signal. The greater the input current, the greater the power regulation ratio and the greater the output power of the control power supply. That is, the power regulation ratio is linearly positively correlated with the output power of the control power supply.

[0068] The power regulation sampling circuit is mainly composed of an operational amplifier U1, a diode D1, a diode D2, a resistor R1, a resistor R2, a capacitor C1 and a capacitor C2. The resistor R2 is connected in series with the resistor R1, and the capacitor C1 is connected in parallel to the resistor R1. One end of the resistor R1 is electrically connected to the anode of the diode D1. The 4-20mA analog signal is converted into a voltage signal after passing through the resistors R1 and R2. R1 and R2 are connected to the positive input terminal of the operational amplifier after voltage division. The two diodes D1 and the diode D2 are connected in series, wherein the anode of the diode D1 is connected to GND, the connection part of the diode D1 and the diode D2 is connected to the positive input terminal of the operational amplifier U1, and the cathode of the diode D2 is connected to VCC; the upper operational amplifier U1 is electrically connected to the VCC power supply terminal, the inverting input terminal, the negative input terminal and the output terminal, and the output is connected to the ADC1 pin of the DSP main control chip.

[0069] The external input signal is converted into a 1-5V voltage signal after being divided by resistors R1 and R2, and is transmitted to the positive electrode of the comparator U1. After the negative electrode of the comparator is short-circuited with the output side, a voltage follower is formed, which can adjust the input and output impedance of the circuit and realize the unity gain circuit as an electrical buffer to isolate circuits or devices from each other and prevent adverse interactions.

[0070] Step 3: Install a current and voltage signal acquisition module at the output end of the control power supply to collect the real-time output current and voltage values ​​of each phase of electricity, and collect the real-time current and voltage signals for preprocessing. According to the sampling ratio of the acquisition circuit, calculate the effective value of voltage and effective value of current of each phase of electricity, and calculate the single-cycle power through the effective values ​​of voltage and current.

[0071] Furthermore, the specific steps of collecting real-time current and voltage signals for preprocessing are: collecting data once every 0.001ms, collecting data 200 times, and calculating the effective value of the collected data. The specific calculation formula is:

[0072]

[0073] Among them, a rms is the effective value of voltage and current signal, a n is the data collected for the nth time, where n is a positive integer, n=1, 2…200;

[0074] The calculation formula for the output power of the power supply to be controlled is:

[0075]

[0076] Among them, P sin is the output power, X A , C B , C C are the current values ​​in the three-phase AC phase A, phase B, and phase C circuits, U AB , U BC The line voltages between phases A and B, and between phases B and C in the three-phase AC A, B, and C circuits are respectively;

[0077]

[0078]

[0079] Among them, U AB U is the line voltage between phase A and phase B in the three-phase AC circuit. BC U is the line voltage between phase B and phase C in the three-phase AC A, B, and C circuits. A is the line voltage of phase A, U B is the line voltage of phase B, U C is the line voltage of phase C.

[0080] Step 4: Based on the expected output power and the single-cycle power, calculate the number of cycles required to adjust the expected power within the cycle time. By setting the adjustment accuracy value, calculate the length of the small adjustment cycle within the cycle time and the number of cycles in the small cycle.

[0081] Frequency refers to the time required for alternating current to complete a complete change. One cycle of a sine wave is the frequency of alternating current. It is used to describe the number of repetitions of a periodic phenomenon or the number of cycles per unit time. The unit of frequency is Hertz (Hz), which represents the number of changes per second.

[0082] Regulation accuracy refers to the minimum change that a power control system can distinguish or adjust. High resolution allows for more detailed adjustment of output voltage or current, and is suitable for applications that require very fine control.

[0083] Furthermore, the calculation formula for calculating the number of cycles required to adjust the desired power within the cycle time is:

[0084]

[0085] Among them, X is the frequency that needs to be turned on, T is the adjustment period, P sin is the output power, P exp is the expected power, t is a single cycle;

[0086] The calculation formula for calculating the time length of the small cycle within the cycle time and the number of cycles in the small cycle is:

[0087]

[0088]

[0089] Where M is the length of the small cycle, q is the adjustment accuracy value, and N is the number of cycles in the small cycle;

[0090] The small cycle refers to the minimum periodic cycle with evenly distributed cycles within the cycle time. The number of cycles in the small cycle refers to the number of cycles output by the minimum cycle.

[0091] Step 5: Based on the small cycle and the number of cycles within the small cycle, the cycles are evenly distributed within the cycle time through calculation. Based on the cycle distribution and the rising edge signal of the PWM wave signal, the controller module controls the output of the cycle by controlling the opening and closing of the thyristor, thereby adjusting the output of the control power supply.

[0092] Furthermore, the specific logic for evenly distributing the cycles within the period time is:

[0093]

[0094] When N>X-N, first cycle M+1 and M small cycles alternately for X-N times, and then cycle M+1 small cycles for X-2N times;

[0095] When N <X―N,先N次交替循环M+1和M小周期,再循环X―2N次M小周期。

[0096] The purpose of the variable cycle algorithm is to distribute the cycles that need to be opened as evenly as possible. After calculating multiple small cycles and the number of small cycles, each opened cycle needs to be distributed as evenly as possible. When N>X-N, first cycle M+1 and M small cycles alternately for X-N times, then cycle M+1 small cycles for X-2N times. When N <X―N,先N次交替循环M+1和M小周期,再循环X―2N次M小周期。

[0097] For example, it is calculated that 17 waves need to be turned on within 100 cycles. At this time, it is calculated that M=5, N=15, that is, 6(M+1) and 5(M) are the widths of the small cycles after division, 15(N) and 2(XN) are the number of executions of the two small cycles. At this time, N>XN, so the cycle lengths of 6 and 5 are alternately cycled twice, that is, the thyristor is turned on once every 6 sine waves, and then the thyristor is turned on once every 5 sine waves. After completing this stage, 13 cycles of 6 are cycled again, and the 17 conductive sine waves are evenly distributed.

[0098] The present invention converts a collected zero-crossing signal of alternating current into a PWM wave signal, collects a power regulation signal, calculates a power regulation ratio, calculates the output expected power of the power supply to be controlled based on the power regulation ratio and the rated power of the control power supply, calculates the single-cycle power based on the real-time output current value and voltage value of the control power supply, calculates the number of cycles required to be turned on within a cycle time to adjust the expected power, as well as the time length of a small adjustment cycle within the cycle time and the number of cycles within the small cycle based on the output expected power and the single-cycle power, so that the cycles are evenly distributed within the cycle time. According to the cycle distribution and the rising edge signal of the PWM wave signal, a controller module controls the output of the cycle by controlling the on and off of a thyristor, thereby adjusting the output power of the control power supply. The present invention performs feedback based on the output voltage and current signals to form a closed-loop control, and simultaneously adopts a variable cycle algorithm to distribute the cycles required to be output as evenly as possible within the cycle time, so that the power output is more balanced. At the same time, each cycle is adjusted and output at zero point, so that the voltage has no overshoot or oscillation.

[0099] The above formulas are all dimensionless and numerical calculations. The formulas are obtained by collecting a large amount of data and performing software simulation to obtain the most recent real situation. The preset parameters in the formulas are set by technicians in this field according to actual conditions.

[0100] The above embodiments can be implemented in whole or in part by software, hardware, firmware, or any other combination thereof. When implemented using software, the above embodiments can be implemented in whole or in part in the form of a computer program product. Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed by hardware or software depends on the specific application and design constraints of the technical solution.

[0101] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, and may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment as needed.

[0102] The above is only a specific implementation method of the present application, but the scope of protection of the present application is not limited thereto. Any technician familiar with this technical field can easily think of changes or replacements within the technical scope disclosed in this application, which should be covered by the scope of protection of the present application.

Claims

1. A closed-loop variable-cycle control algorithm for a power control power supply, characterized in that: The specific steps include: Step 1: Connect the power supply to be controlled to the voltage stabilizer and the filter in sequence to obtain a stable power supply to be controlled. Collect the zero-crossing signal of each phase of the three-phase AC power of the power supply to be controlled, and convert the positive half-wave of the AC sine wave into a high-level pulse signal and the negative half-wave into a low-level pulse signal (PWM wave signal), and send it to the controller module; Step 2: By inputting a power regulation signal into the acquisition end of the power regulation sampling circuit, a power regulation ratio between the power regulation signal and the sampling signal range of the sampling circuit is calculated. Based on the power regulation ratio and the rated power of the control power supply, the expected output power of the power supply to be controlled is calculated; Step 3: By collecting the real-time current and voltage signals of the output end of the control power supply and pre-processing the collected real-time current and voltage signals, the effective value of the phase voltage and the effective value of the phase current of each phase are calculated, and the single-cycle power of the output power supply is calculated based on the effective values ​​of the voltage and current; Step 4: Set the adjustment accuracy value for the expected output power. Based on the expected output power and the single-cycle power, calculate the number of cycles that need to be turned on within the cycle time. Based on the number of cycles, calculate the length of the small adjustment cycle within the cycle time and the number of cycles in the small cycle according to the variable cycle algorithm. Step 5: Based on the small cycle and the number of cycles within the small cycle, the cycles are evenly distributed within the cycle time through calculation. Based on the cycle distribution and the rising edge signal of the PWM wave signal, the controller module controls the output of the control cycle by controlling the opening and closing of the thyristor to adjust the power supply power; The calculation formula of the power adjustment ratio is: in, is the power regulation ratio, It is the power adjustment signal inputted by the acquisition end; The calculation formula for the expected power of the power supply to be controlled is: in, is the expected power, is the rated power, is the power regulation ratio; The calculation formula for calculating the time length of the small adjustment cycle within the cycle time and the number of cycles in the small cycle according to the variable cycle algorithm is: in, is the frequency that needs to be turned on. To adjust the cycle, is the output power, is the expected power, is a single cycle; The calculation formula for calculating the time length of the small cycle within the cycle time and the number of cycles in the small cycle is: in, is the length of the small cycle, To adjust the accuracy value, is the number of cycles in the small cycle.

2. The closed-loop variable-cycle control algorithm for a power control power supply according to claim 1, characterized in that: The specific steps of preprocessing the collected real-time current and voltage signals and calculating the effective value of the phase voltage and the effective value of the phase current of each phase are: Data is collected every 0.001ms. After collecting data 200 times, the effective value of the data is calculated. The specific calculation formula is: in, is the effective value of voltage and current signal, For the The data collected, is a positive integer, ; The calculation formula for the output power of the power supply to be controlled is: in, is the output power, , are the current values ​​in the three-phase AC phase A, phase B, and phase C circuits respectively. , They are the line voltage between phase A and phase B, and the line voltage between phase B and phase C in the three-phase AC phase A, phase B, and phase C circuits respectively.

3. The closed-loop variable-cycle control algorithm for a power control power supply according to claim 2, characterized in that: The calculation formulas for the line voltage between phase A and phase B, and the line voltage between phase B and phase C are: in, The line voltage between phase A and phase B in the three-phase AC circuit is The line voltage between phase B and phase C in the three-phase AC A, B, and C circuits is: is the line voltage of phase A, is the line voltage of phase B, is the line voltage of phase C.

4. The closed-loop variable-cycle control algorithm for a power control power supply according to claim 1, characterized in that: The specific logic for evenly distributing the cycles within the period is: when ,First Alternating cycle and Small cycle, recycle Second-rate Small cycle; when ,First Alternating cycle and Small cycle, recycle Second-rate Small cycle.

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