Control method for pulse power supply operation time sequence and pulse number based on state machine

Abstract

The invention discloses a pulse power supply operation time sequence and pulse number control method based on a state machine. The method comprises the following steps: obtaining charging time and discharging waiting time of a pulse power supply according to the capacity and voltage of an electricity storage capacitor of the pulse power supply; obtaining the discharge time and the charge waiting time of the pulse power supply according to the power storage capacitor capacity and the discharge inductance of the pulse power supply; according to the charging time, the charging waiting time, the discharging time and the discharging waiting time of the pulse power supply, the discharging frequency of the pulse power supply is obtained; setting a power supply operation state according to the discharge frequency of the pulse power supply. The invention relates to the technical field of pulse laser power supplies, and solves the technical problem that the existing method cannot realize accurate control of the number of output pulses.

Description

Technical Field

[0001] The invention belongs to the technical field of pulse laser power supplies, and in particular is a method for controlling the operating timing and pulse quantity of a pulse power supply based on a state machine. Background Art

[0002] Solid-state lasers are widely used in many fields such as industry, agriculture, medicine and military, and they are highly valued. As the core driving component, high-power and high-voltage pulse power supplies are particularly concerned. In these pulse power supply circuits, isolated DC / DC converters play a vital role. They not only have the characteristics of high power density and high efficiency, but also their RLC pulse forming network can realize high-current and high-energy pulse discharge. In order to meet the specific requirements of pulse power supply in terms of charging time, discharge network time and repetition frequency, it is particularly important to design a precise and controllable pulse power supply control program timer.

[0003] However, traditional high-power high-voltage pulse power supplies have problems such as low charging efficiency and insufficient single-pulse energy, which limits the controllability of the number of output pulses. The invention patent with publication number CN112909722B discloses "a high-power pulse laser power supply circuit". The invention adopts a topological structure of BUCK+ linear constant current source parallel output. The lithium battery power is boosted and stored in a 500V capacitor array through staggered parallel BOOST and control parts to provide an output environment for the subsequent stage. The hysteresis BUCK circuit and control part quickly charge and coordinate the linear constant current source output. The voltage hysteresis control stabilizes the 300V capacitor voltage. The linear constant current source circuit and its control part receive signals to output specific pulse currents and have overcurrent protection functions, thereby solving the existing high-power laser driving power supply problem.

[0004] However, the prior art does not fully consider the issues of charging voltage and output pulse energy when considering pulse power supply energy storage, resulting in a low charging voltage and inability to effectively control the number of pulses of the pulse power supply. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art; to this end, the present invention proposes a control method for the operating timing and pulse number of a pulse power supply based on a state machine, which is used to solve the technical problem that the existing method cannot achieve precise control of the output pulse number.

[0006] To achieve the above object, a first aspect of the present invention provides a method for controlling the operation timing and pulse quantity of a pulse power supply based on a state machine, comprising:

[0007] S1, obtain the charging time and discharge waiting time of the pulse power supply according to the storage capacitor capacity C2 and the storage capacitor voltage Uout of the pulse power supply;

[0008] S2, according to the storage capacitor C2 and the discharge inductor L of the pulse power supply, the discharge time and charging waiting time of the pulse power supply are obtained;

[0009] S3, obtaining the discharge frequency of the pulse power supply according to the complete charge and discharge operation cycle of the pulse power supply and the charging time and charging waiting time, and the discharging time and discharging waiting time of the pulse power supply;

[0010] S4, setting the power supply operation state according to the discharge frequency of the pulse power supply.

[0011] Further, the charging time and the discharge waiting time of the pulse power supply are obtained according to the storage capacitor capacity C2 and the storage capacitor voltage Uout of the pulse power supply, including:

[0012] A1, calculate the ratio of the charging cycle Ts to the total charging cycle Tc, and obtain Ks;

[0013] A2, according to the formula IC2,avg = (8Cr × fr × Udc) / n, the constant current charging current IC2,avg of the pulse power supply is calculated; where Cr represents the resonant cavity capacitance of the pulse power supply, fr represents the switching frequency of the pulse power supply, Udc represents the output voltage of the three-phase rectifier bridge of the pulse power supply, and n represents the transformer ratio of the pulse power supply;

[0014] A3, calculating the charging time and the discharge waiting time of the pulse power supply according to the Ks and the constant current charging current of the pulse power supply.

[0015] Furthermore, the calculation formula of the charging time is: ts=(C2×Uout) / IC2,avg.

[0016] Furthermore, the calculation formula of the discharge waiting time is: tb = [C2 × Uout × (1-Ks)] / (I C2,avg ×Ks).

[0017] Furthermore, the calculation formula of the discharge time is: td=2π√LC2.

[0018] Furthermore, the calculation formula of the charging waiting time is: tj=[2π×(1-Kd)×√LC2] / Kd; wherein Kd represents the ratio of the discharge period T to the total discharge period Tdisc.

[0019] Furthermore, the calculation formula of the discharge frequency of the pulse power supply is: f=1 / (ts+tb+td+tj).

[0020] Further, setting the power supply operation state according to the discharge frequency of the pulse power supply includes:

[0021] C1, the number of discharges of the pulse power supply to the xenon lamp pulse per unit time is calculated according to the discharge frequency of the pulse power supply;

[0022] C3 switches the operating state of the state machine according to the number of discharges.

[0023] Furthermore, the switching of the operating state of the state machine according to the number of discharges includes:

[0024] Ready state: The pulse power supply main circuit is closed, the switch power supply is energized, the power supply is soft-started, and the power supply enters state 1;

[0025] State 1: The xenon lamp enters pre-combustion, and the voltage and frequency are set by the state machine;

[0026] State 2: Turn on the start button of the power supply, PWM generates waves, the DC / DC converter starts, and the power supply starts charging. When the power supply is charged to the set voltage, it enters state 3;

[0027] State 3: PWM stops emitting waves, the DC / DC converter is paused, and enters state 4;

[0028] State 4: Turn on the thyristor, the power supply discharges, and the discharge waiting time and discharge frequency are set according to the discharge waiting time tb and the discharge frequency f of the pulse power supply;

[0029] State 5: Count the number of discharges according to state 4. When the number of discharges does not reach the set value, return to state 2; when the number of discharges reaches the set value, stop the discharge operation.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] PWM pulse width modulation technology is introduced for pulse power supply, constant current charging method is adopted, and the charging voltage and average output power requirements of energy storage capacitor are taken into consideration; first, the appropriate charging reserve time and charging waiting time are calculated according to these requirements; then, the actual discharge time and discharge waiting time are calculated according to the circuit parameters of the pulse forming network. By combining PWM pulse width modulation technology and constant current charging method, the isolation of pulse power supply charging and discharging is realized, which can effectively prevent the occurrence of accidents where thyristor cannot be turned off, and provide a reliable solution for the stable operation and safety of pulse power supply;

[0032] According to the requirements of the charging time of the energy storage capacitor of the high-voltage pulse power supply and the pulse width of the discharge network, the operation cycle of the pulse power supply charging and discharging is calculated; by controlling the maximum waiting time of a single charge of the pulse power supply, the maximum number of charge and discharge times of the pulse power supply per unit (second) is controlled, and the discharge frequency control of the pulse power supply is realized;

[0033] The state machine of the high-power high-voltage pulse power supply controller program under different discharge frequencies identifies the number of times it enters the discharge action state, calculates the number of pulse discharges of the pulse power supply to the xenon lamp, jumps out of the pulse power supply charge and discharge cycle, and realizes precise control of the pulse power supply charge and discharge times. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0035] Figure 1 A control block diagram of a main circuit obtained according to the main circuit topology parameters of a pulse power supply provided by the present invention;

[0036] Figure 2 A flow chart of the main circuit parameter design of a high-power high-voltage pulse power supply provided by the present invention;

[0037] Figure 3 A loop switching diagram of the operating state of the high-power high-voltage pulse power supply provided by the present invention;

[0038] Figure 4 The charging and discharging voltage, current and time design waveform diagram of the high-power high-voltage pulse power supply provided by the present invention;

[0039] Figure 5 The discharge waveform diagram of the high-power high-voltage pulse power supply provided by the present invention;

[0040] Figure 6 This is a diagram showing the experimental results of the high-power high-voltage pulse power supply timer design provided by the present invention;

[0041] Figure 7 A schematic flow chart of a method for controlling the operating timing and pulse quantity of a pulse power supply based on a state machine provided by the present invention. DETAILED DESCRIPTION

[0042] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] See also Figure 1-Figure 7 The embodiment of the present invention provides a method for controlling the operation timing and pulse quantity of a pulse power supply based on a state machine, including:

[0044] S1, according to the pulse power supply storage capacitor capacity C2 and storage capacitor voltage U out Get the charging time and discharge waiting time of the pulse power supply;

[0045] S2, according to the storage capacitor C2 and the discharge inductor L of the pulse power supply, the discharge time and charging waiting time of the pulse power supply are obtained;

[0046] S3, obtaining the discharge frequency of the pulse power supply according to the complete charge and discharge operation cycle of the pulse power supply and the charging time and charging waiting time, and the discharging time and discharging waiting time of the pulse power supply;

[0047] S4, setting the power supply operation state according to the discharge frequency of the pulse power supply.

[0048] It should be noted that the method of the present invention is implemented based on a high-power, high-voltage pulse power supply circuit topology;

[0049] The high-power high-voltage pulse power supply circuit topology includes: a three-phase rectifier bridge and a filter capacitor C1, an isolated resonant cavity including a resonant capacitor C r , resonant inductor L r , transformer ratio n and rectifier bridge, the pulse forming network includes xenon lamp resistor R, discharge inductor L, and energy storage capacitor C2. According to the design parameters of high-power high-voltage pulse power supply, the pulse power supply control program timer is designed to control the operation cycle of pulse power supply charge and discharge. Finally, this method is used to realize the accurate control of pulse power supply charge and discharge times. The control network is as follows Figure 1 shown.

[0050] In this embodiment, before calculating the charge and discharge time of the pulse power supply, it is first necessary to understand the operation cycle of the pulse power supply and the relationship between the input and output parameters of the power supply, including:

[0051] The average output power of the pulse power supply: P av =WT all ;

[0052] Single pulse energy of pulse power supply:

[0053] The charge in the energy storage capacitor of the pulse power supply for a single output is: q = C2U out ;

[0054] A single charge and discharge complete operation cycle of a pulse power supply:

[0055] Among them, T all represents a single charge and discharge cycle under different frequency states of the pulse power supply, f represents the maximum repetition frequency of the pulse power supply, where W represents the single discharge energy of the capacitor of the pulse power supply, Pav Indicates the average output power of the pulse power supply, U out represents the charging voltage of the pulse power supply storage capacitor, C2 represents the storage capacitor capacity of the pulse power supply, T c Indicates the total charging cycle of the pulse power supply, T disc Indicates the total discharge cycle of the pulse power supply.

[0056] Then according to the storage capacitor capacity C2 and the storage capacitor voltage U of the pulse power supply out To obtain the charging time and discharge waiting time of the pulse power supply, the specific steps are:

[0057] The sum of the actual charging cycle (charging action and charging completion) and the charging and discharging interval (discharging waiting) of the pulse power supply storage capacitor: T c =T s +T b ;

[0058] The actual charging cycle (charging action and charging completion) of the pulse power supply storage capacitor accounts for the total charging cycle:

[0059] The proportion of the charge-discharge interval (discharge waiting) cycle in the total charging cycle:

[0060] The pulse power supply storage capacitor adopts constant current charging method:

[0061] The pulse power supply charging time is:

[0062] The pulse power supply charge and discharge interval (discharge waiting) time is:

[0063] Among them, U dc Indicates the output voltage of the three-phase rectifier bridge of the pulse power supply, T s Indicates the actual charging cycle of the pulse power supply, T b Indicates the charge and discharge interval (discharge waiting) cycle, I C2,avg Indicates the current of the pulse power supply storage capacitor using constant current charging, C r represents the capacitance of the pulse power supply resonant cavity, f r represents the switching frequency of the pulse power supply, n represents the transformer ratio of the pulse power supply, t s Indicates the charging time of the pulse power supply, t b Indicates the discharge waiting time of the pulse power supply;

[0064] According to the storage capacitor C2 and the discharge inductor L of the pulse power supply, the discharge time and charging waiting time of the pulse power supply are obtained. The specific steps are:

[0065] The sum of the actual discharge cycle of the pulse power supply and the discharge and charge interval (charging waiting) cycle: T disc =T d +T j ;

[0066] The actual discharge cycle of the pulse power supply accounts for the total discharge cycle:

[0067] The proportion of the discharge-charge interval (charging waiting) period in the total discharge period is:

[0068] The actual discharge time of the pulse power supply is:

[0069] The charging interval (charging waiting) time is:

[0070] Where, L represents the pulse power supply discharge inductance, t d Indicates the discharge time of the pulse power supply, t j Indicates the charging waiting time of the pulse power supply;

[0071] Next, according to the complete charge and discharge operation cycle of the pulse power supply and the charging time and charging waiting time, discharging time and discharging waiting time of the pulse power supply, the discharge frequency of the pulse power supply is obtained:

[0072] A single charge and discharge complete operation cycle of a pulse power supply:

[0073] Single charge and discharge complete operation time of pulse power supply:

[0074] The pulse power supply discharge frequency within the unit (second) time of the pulse power supply is:

[0075] Among them, t all It represents the complete running time of a single charge and discharge of the pulse power supply, and f represents the discharge frequency of the pulse power supply;

[0076] Finally, according to the requirements of the charging time and discharging time of the pulse power supply, as well as the discharge frequency of the pulse power supply, the state machine of the pulse power supply controller program identifies the number of times the discharge action state is entered, and the number of pulse discharges of the pulse power supply to the xenon lamp is calculated to set the power supply operation state, so as to achieve accurate and controllable pulse power supply discharge times;

[0077] The specific operation of setting the power supply operation state according to the discharge frequency of the pulse power supply is:

[0078] Ready state: The pulse power supply main circuit is closed, the switch power supply is energized, the power supply is soft-started, and the power supply enters state 1;

[0079] State 1: The xenon lamp enters pre-combustion, and the voltage and frequency are set by the state machine;

[0080] State 2: Turn on the start button of the power supply, PWM generates waves, the DC / DC converter starts, and the power supply starts charging. When the power supply is charged to the set voltage, it enters state 3;

[0081] State 3: PWM stops emitting waves, the DC / DC converter is paused, and enters state 4;

[0082] State 4: Turn on the thyristor, the power supply discharges, and the discharge waiting time and discharge frequency are set according to tb and f;

[0083] State 5: Count the number of discharges according to state 4. When the number of discharges does not reach the set value, return to state 2; when the number of discharges reaches the set value, stop the discharge operation.

[0084] like Figure 4 As shown in the figure, it is a design waveform diagram of the charging and discharging voltage, current and time of the high-power high-voltage pulse power supply obtained by the present invention provided in this embodiment. It can be seen from the figure that:

[0085] When t=t0~t1, the capacitor is charged by constant current, the DC / DC converter is running, the capacitor voltage rises rapidly, and the pulse power supply charging and charging completion time is ts;

[0086] When t=t1~t2, the capacitor is fully charged, the DC / DC converter stops, the charging current is zero, the capacitor voltage remains unchanged, and the pulse power supply charge and discharge interval (discharge waiting) time is tb;

[0087] When t=t2~t3, the RLC pulse forms a network discharge, the capacitor voltage drops rapidly, and the pulse power supply discharge time is td;

[0088] When t=t3~t4, the RLC pulse forming network stops discharging, the capacitor voltage is zero, and the pulse power supply discharge and charge isolation time (charging waiting time) is t j , implement isolation and prevent the thyristor from being unable to shut down.

[0089] like Figure 5 As shown in the figure, the high-power high-voltage pulse power supply discharge waveform, from which it can be seen that the energy storage capacitor of the pulse forming network discharges to the xenon lamp through the inductor. The pulse power supply discharge waveform is a large-amplitude critical damping oscillation. When the voltage and current increase to a certain level, the waveform is non-periodic, and the voltage and current will not oscillate periodically, but slowly return to zero.

[0090] In this embodiment, in order to verify the feasibility of the proposed technical solution, an experimental circuit of a high-power high-voltage pulse power supply main circuit topology was built.

[0091] The main circuit parameters and experimental conditions are as follows: Set the maximum charging voltage of the pulse power supply to 2200V, the input voltage of the three-phase rectifier network to 380V, and the filter capacitor to 420μF. The switching frequency range of the resonant cavity is set to 22kHZ, the value of the resonant capacitor is 0.44μF, the value of the resonant inductor is 28μH, the transformer ratio is 1:5.3, and the value of the energy storage capacitor is 300μF. The pulse forming network, the discharge inductor value is 80μH, and the calculation process is as follows:

[0092] The three-phase bridge rectifier output voltage is:

[0093] Pulse power supply storage capacitor charging current:

[0094] The actual charging time of the pulse power supply is:

[0095] The pulse discharge time of the pulse power supply is: The actual discharge cycle of the pulse power supply accounts for the total cycle:

[0096] According to the above calculation results, set the state machine parameters:

[0097] The state machine sets the pulse power supply storage capacitor reserved charging cycle as a percentage of the total cycle:

[0098] The proportion of the charge-discharge interval (discharge waiting) cycle in the total charging cycle:

[0099] The charging time is required to be greater than 85ms, so the pulse power supply charging time is set to: t s =K s T c ≈90ms, the pulse power supply charge and discharge interval (discharge waiting) time is: t b =(1-K s )T c ≈5ms;

[0100] The proportion of the state machine charging interval (charging waiting) cycle in the total cycle is: The charging interval (charging waiting) time is:

[0101] Therefore, the complete running time of a single charge and discharge of the pulse power supply is:

[0102]

[0103] The pulse power supply discharge frequency within the unit (second) time of the pulse power supply is:

[0104] According to the above calculation process, the calculation results of this embodiment are: the pulse power supply charging time is reserved for 90ms, the charging and discharging interval (discharging waiting time) is 5ms, the discharging and charging interval (charging waiting time) is 5ms, the output frequency is 10Hz, and the wave is stopped after 10 discharges.

[0105] The designed pulse power supply discharge times are: the times the state machine enters the discharge state (state 4) is judged, when the discharge times do not reach the set value, it returns to state 2, when the discharge times reach the set value, the charging and discharging is stopped.

[0106] like Figure 6 As shown, this is a diagram of the experimental results of the high-power high-voltage pulse power supply timer design in the present invention.

[0107] Part of the data in the above formula is calculated by removing the dimension and taking its numerical value. The formula is a formula closest to the actual situation obtained by software simulation of a large amount of collected data; the preset parameters and preset thresholds in the formula are set by technical personnel in this field according to actual conditions or obtained through simulation of a large amount of data.

[0108] Working principle of the present invention:

[0109] According to the pulse power supply storage capacitor capacity C2, storage capacitor voltage U out , discharge inductor L and three-phase rectifier bridge output voltage U dc , resonant cavity capacitance C r , switching frequency f r , transformer ratio n and other parameters to calculate charging time, discharging time, charging waiting time and discharging waiting time, so as to achieve precise control of the pulse power supply charging and discharging timing and pulse quantity, and ensure the stable operation of the pulse power supply under different working conditions. At the same time, through the switching and control of each operating state by the state machine, the whole system works in an orderly manner according to the predetermined logic, which improves the reliability and stability of the pulse power supply.

[0110] The above embodiments are only used to illustrate the technical method of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical method of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical method of the present invention.

Claims

1. A method for controlling the operation timing and pulse quantity of a pulse power supply based on a state machine, characterized in that: include: S1, obtain the charging time and discharge waiting time of the pulse power supply according to the storage capacitor capacity C2 and the storage capacitor voltage Uout of the pulse power supply; S2, according to the storage capacitor C2 and the discharge inductor L of the pulse power supply, the discharge time and charging waiting time of the pulse power supply are obtained; S3, obtaining the discharge frequency of the pulse power supply according to the complete charge and discharge operation cycle of the pulse power supply and the charging time and charging waiting time, and the discharging time and discharging waiting time of the pulse power supply; S4, setting the power supply operation state according to the discharge frequency of the pulse power supply.

2. The method for controlling the operation timing and pulse quantity of a pulse power supply based on a state machine according to claim 1, characterized in that: The method of obtaining the charging time and the discharge waiting time of the pulse power supply according to the storage capacitor capacity C2 and the storage capacitor voltage Uout of the pulse power supply comprises: A1, calculate the ratio of the charging cycle Ts to the total charging cycle Tc, and obtain Ks; A2, according to formula I C2,avg =(8Cr×fr×Udc) / n, calculate the constant current charging current I of the pulse power supply C2,avg ; Wherein, Cr represents the resonant cavity capacitance of the pulse power supply, fr represents the switching frequency of the pulse power supply, Udc represents the output voltage of the three-phase rectifier bridge of the pulse power supply, and n represents the transformer ratio of the pulse power supply; A3, calculating the charging time and the discharge waiting time of the pulse power supply according to the Ks and the constant current charging current of the pulse power supply.

3. The method for controlling the operation timing and pulse quantity of a pulse power supply based on a state machine according to claim 2, characterized in that: The calculation formula of the charging time is: ts = (C2 × Uout) / I C2,avg .

4. The method for controlling the pulse power supply operation timing and pulse quantity based on a state machine according to claim 2, characterized in that: The calculation formula of the discharge waiting time is: tb = [C2 × Uout × (1-Ks)] / (I C2,avg ×Ks).

5. The method for controlling the operation timing and pulse quantity of a pulse power supply based on a state machine according to claim 1, characterized in that: The calculation formula of the discharge time is: td=2π√LC2.

6. The method for controlling the pulse power supply operation timing and pulse quantity based on a state machine according to claim 1, characterized in that: The calculation formula of the charging waiting time is: tj=[2π×(1-Kd)×√LC2] / Kd; wherein Kd represents the ratio of the discharge period T to the total discharge period Tdisc.

7. The method for controlling the pulse power supply operation timing and pulse quantity based on a state machine according to claim 1, characterized in that: The calculation formula of the discharge frequency of the pulse power supply is: f=1 / (ts+tb+td+tj).

8. The method for controlling the operation timing and pulse quantity of a pulse power supply based on a state machine according to claim 1, characterized in that: The step of setting the power supply operation state according to the discharge frequency of the pulse power supply includes: C1, the number of discharges of the pulse power supply to the xenon lamp pulse per unit time is calculated according to the discharge frequency of the pulse power supply; C3 switches the operating state of the state machine according to the number of discharges.

9. The method for controlling the pulse power supply operation timing and pulse quantity based on a state machine according to claim 8, characterized in that: The switching of the operating state of the state machine according to the number of discharges includes: Ready state: The pulse power supply main circuit is closed, the switch power supply is energized, the power supply is soft-started, and the power supply enters state 1; State 1: The xenon lamp enters pre-combustion, and the voltage and frequency are set by the state machine; State 2: Turn on the start button of the power supply, PWM generates waves, the DC / DC converter starts, and the power supply starts charging. When the power supply is charged to the set voltage, it enters state 3; State 3: PWM stops emitting waves, the DC / DC converter is paused, and enters state 4; State 4: Turn on the thyristor, the power supply discharges, and the discharge waiting time and discharge frequency are set according to the discharge waiting time tb and the discharge frequency f of the pulse power supply; State 5: The number of discharges is obtained according to the statistics of state 4. When the number of discharges does not reach the set value, the state returns to state 2; when the number of discharges reaches the set value, the discharge operation is stopped.

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