Single voltage sensor module voltage detection method for PSM high-voltage power supply

Abstract

The invention belongs to the related technical field of high-voltage power supplies, and particularly relates to a single voltage sensor module voltage detection method for a PSM high-voltage power supply, which comprises the following steps of: determining a target power supply module in a PWM modulation state through a PWM module cycle control strategy, and performing voltage sampling at a direct output end of the PSM high-voltage power supply by using a single voltage sensor; and the voltage value of the target power supply module is obtained by calculating the difference value of the sampling voltage signals. According to the method, the hardware structure is simplified, and the cost is reduced. In addition, the system also has overvoltage and undervoltage protection functions, monitors a voltage value of the power supply module, compares the voltage value with a preset threshold value, and executes protection actions when the voltage value is abnormal, such as locking a trigger signal of a switching tube IGBT and lightening an indicator lamp, so as to ensure safe operation of the system. According to the invention, the detection method of the high-voltage power supply is optimized, the safety and reliability of the system are enhanced, and the method has wide application prospect and popularization value.

Description

Technical Field

[0001] The present invention belongs to the technical field related to high-voltage power supplies, and particularly relates to a method for detecting the voltage of a single voltage sensor module of a PSM high-voltage power supply. Background Art

[0002] The PSM high-voltage power supply is an important part of the Electron Cyclotron Resonance Heating (ECRH) system of a Tokamak device. The PSM high-voltage power supply is composed of a large number of power modules connected in series to obtain the required high-voltage DC output. When the voltage of a power module is too high, an overvoltage state occurs. After the PSM high-voltage power supply is turned on, the load overshoot is large, which will endanger the safety of the load. When the voltage of a power module is too low, an undervoltage state occurs, and the output of the high-voltage power supply will not be able to meet the load requirements. Therefore, in order to ensure that the output voltage of the power module is within a safe and stable range and to ensure that the power system can operate normally, over-undervoltage protection is required. Voltage detection is a prerequisite for over-undervoltage protection. Usually, the PSM high-voltage power supply consists of hundreds of power modules. The traditional detection method requires the use of hundreds of corresponding voltage sensors to detect the voltage of the power modules. On the one hand, this leads to a relatively high detection cost. On the other hand, the number of sensors required for detection is large, and the overall reliability of the system is low. Therefore, how to reduce the number of required voltage sensors, reduce the voltage detection cost of the PSM high-voltage power supply, and improve the overall reliability of the system is an important issue in the voltage detection of the PSM high-voltage power supply. Summary of the Invention

[0003] The purpose of the present invention is to provide a method for detecting the voltage of a single voltage sensor module of a PSM high-voltage power supply to solve the problems of a large number of voltage sensors required for detecting the module voltage of the existing PSM high-voltage power supply and a high detection cost as proposed in the background art.

[0004] The present invention achieves the above purpose through the following technical solutions:

[0005] A method for detecting the voltage of a single voltage sensor module of a PSM high-voltage power supply, the PSM high-voltage power supply includes a plurality of power modules and a signal generation module, and the method includes:

[0006] Determine the target power module currently in the PWM modulation state according to the PWM module cyclic control strategy;

[0007] Perform voltage sampling according to the voltage signal of the voltage sensor at the direct output end of the PSM high-voltage power supply and the set acquisition mechanism to obtain a sampled voltage signal;

[0008] Determine the voltage value of the target power module according to the sampled voltage signal;

[0009] The PWM module traverses each power module in the PSM high-voltage power supply and sequentially detects the voltage of each power module.

[0010] Further, the voltage sensor is connected in parallel to the direct output terminal of the PSM high-voltage power supply, and one voltage sensor is provided.

[0011] Further, determining the target power module currently in the PWM modulation state according to the PWM module cyclic control strategy includes:

[0012] Set N - 1 of the N power modules to the through state, where N is an integer greater than 1, and the remaining 1 is set to the PWM modulation state, and control the through signal (SM signal) and the PWM signal to cycle and switch between each power module through the PWM module cyclic control unit;

[0013] Read the cyclic control signal of the PWM module cyclic control unit to determine the target power module currently in the PWM modulation state.

[0014] Further, reading the cyclic control signal of the PWM module cyclic control unit to determine the target power module currently in the PWM modulation state includes:

[0015] The cyclic control signal of the PWM module cyclic control unit is an N-bit binary coded signal, each bit corresponding to a power module, and the power module corresponding to the bit with a value of "1" in the output signal is the target power module.

[0016] Further, performing voltage sampling according to the voltage signal of the voltage sensor at the direct output terminal of the PSM high-voltage power supply and the set acquisition mechanism to obtain a sampled voltage signal, including:

[0017] Determine the sampling moment through the PWM signal in the signal generation module, and detect the rising edge or falling edge of the PWM signal by means of interruption;

[0018] After detecting the rising edge or falling edge of the PWM signal, delay for a preset time t to ensure that the switching tube of the detected target power module is in the on or off state;

[0019]

[0020] where D is the duty cycle of the PWM signal and f is the switching frequency;

[0021] Read the analog voltage signal of the voltage sensor and convert it into a digital voltage value through an analog-to-digital converter (ADC);

[0022] Among them, the digital voltage value includes the sampled voltage signal U2 collected after a delay of t after detecting the rising edge of the PWM signal, and the sampled voltage signal U1 collected after a delay of t after detecting the falling edge of the PWM signal.

[0023] Further, determining the voltage value of the target power supply module according to the sampled voltage signal includes:

[0024] Taking the difference between the sampled voltages U2 and U1 of the direct output terminal voltage signal of the PSM high-voltage power supply as the voltage value of the target power supply module.

[0025] Further, the method further includes:

[0026] According to the voltage value of the target power supply module, comparing the calculated voltage value with the preset overvoltage and undervoltage thresholds. If the voltage value of the power supply module exceeds the preset overvoltage or undervoltage threshold, an overvoltage or undervoltage protection action is performed.

[0027] Further, the overvoltage or undervoltage protection action includes:

[0028] Blocking the trigger signal of the switch tube IGBT;

[0029] Turning on the corresponding overvoltage or undervoltage indicator light.

[0030] The beneficial effects of the present invention are as follows:

[0031] 1. The voltage detection circuit proposed by the present invention only uses one voltage sensor. Compared with the traditional voltage detection method of the PSM high-voltage power supply, it greatly reduces the number of required voltage sensors, reduces the detection cost, and improves the reliability of the system. While achieving its own detection purpose, this detection method also takes into account the loss balance of the PSM high-voltage power supply, killing two birds with one stone.

[0032] 2. The present invention also has overvoltage and undervoltage protection functions. By monitoring the voltage value of the power supply module and comparing it with the preset threshold, the system can quickly respond when the voltage is abnormal and perform corresponding protection actions, such as blocking the trigger signal of the switch tube IGBT and lighting the indicator light, thereby effectively preventing the power supply module from being damaged and ensuring the safe operation of the entire system. Description of the Drawings

[0033] Figure 1 It is a schematic flow chart of the single-voltage sensor module voltage detection method for the PSM high-voltage power supply provided by the embodiment of the present application;

[0034] Figure 2 It is a schematic diagram of the voltage detection circuit of the single-voltage sensor module voltage detection method for the PSM high-voltage power supply provided by the embodiment of the present application;

[0035] Figure 3 Schematic diagram of the signal generation module structure for the voltage detection method of the single voltage sensor module of the PSM high-voltage power supply provided by the embodiment of the present application;

[0036] Figure 4 Schematic diagram for determining the PWM power module of the voltage detection method of the single voltage sensor module of the PSM high-voltage power supply provided by the embodiment of the present application;

[0037] Figure 5 Schematic diagram of the voltage acquisition point in the voltage detection method of the single voltage sensor module of the PSM high-voltage power supply provided by the embodiment of the present application;

[0038] Figure 6 Schematic diagram of the voltage detection and over / under voltage protection method flow of the present invention. Detailed implementation manners

[0039] The following further describes the present application in detail with reference to the drawings. It is necessary to point out here that the following detailed implementation manners are only used to further illustrate the present application and cannot be understood as a limitation on the protection scope of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.

[0040] As Figure 2 shown, point A of the PSM high-voltage power supply is the direct output end. A voltage detection method for the single voltage sensor module of the PSM high-voltage power supply proposed by the present invention refers to configuring a voltage sensor at the direct output end A of the PSM high-voltage power supply to replace the N voltage sensors on the low-voltage side of the power supply module in the traditional voltage detection method, and detecting the voltages of each power supply module by combining the voltage signal of this voltage sensor with the PWM module cyclic control strategy and voltage acquisition mechanism.

[0041] Embodiment 1

[0042] As Figures 1-6 shown, this embodiment proposes a voltage detection method for the single voltage sensor module of the PSM high-voltage power supply. The PSM (Pulse Step Modulation) high-voltage power supply includes several power supply modules and a signal generation module. This detection method proposes a voltage detection circuit that can complete the voltage detection of all power supply modules of the PSM high-voltage power supply with only 1 voltage sensor, and introduces the corresponding detection method and the power supply over / under voltage protection method.

[0043] Combined with Figure 2 、 Figure 3As shown in the figure, the voltage detection circuit includes: one voltage sensor and a signal processing unit; more specifically, the voltage sensor is connected in parallel to the direct output terminal of the PSM high-voltage power supply for collecting the voltage signal at the direct output terminal of the PSM high-voltage power supply; the signal processing unit is used to determine the currently detected power module according to the cyclic control signal, convert the voltage signal of the voltage sensor into a digital voltage signal through ADC, determine the voltage acquisition points according to the PWM signal to obtain the values of U1 and U2, and finally calculate the voltage value of the current power module.

[0044] Explanation of the PWM modulation principle: The PWM modulation principle refers to that in the PSM high-voltage power supply, by controlling the switching state of the power module, the output voltage of the power module shows a periodic change of high and low levels in time. This change can adjust the average value of the output voltage by adjusting the time ratio of the high level and the low level (i.e., the duty cycle), so as to achieve precise control of the output voltage of the power module.

[0045] Combined with Figure 1 As shown in the figure, the voltage detection method includes the following steps:

[0046] S1. Determine the target power module currently in the PWM modulation state according to the PWM module cyclic control strategy.

[0047] More specifically, set N - 1 of the N power modules to the direct-through state, where N is an integer greater than 1, and the remaining 1 is set to the PWM modulation state, and control the direct-through signal (marked as the SM signal) and the PWM signal to cycle and switch between each power module through the PWM module cyclic control unit;

[0048] Read the cyclic control signal of the PWM module cyclic control unit to determine the target power module currently in the PWM modulation state; the cyclic control signal of the PWM module cyclic control unit is an N-bit binary encoded signal, each bit corresponding to one power module, and the power module corresponding to the bit with a value of "1" in the output signal is the target power module.

[0049] S2. Perform voltage sampling according to the voltage sensor configured at the direct output terminal of the PSM high-voltage power supply and the set acquisition mechanism to obtain the sampled voltage signal.

[0050] S3. Determine the voltage value of the target power module according to the sampled voltage signal.

[0051] Further preferably, the PWM module cyclically traverses each power module of the PSM high-voltage power supply and sequentially detects all power modules.

[0052] During specific implementation, combined with Figures 3-5As shown in the figure, according to the PSM modulation principle, N - 1 power modules work in the through state, and the remaining 1 power module works in the PWM modulation state. Considering that the power module working in the PWM modulation state has relatively serious losses, a PWM module cyclic control strategy needs to be designed;

[0053] Taking the PSM high - voltage power supply composed of 6 power modules as an example, the input of the cyclic controller is provided by the SM control unit, the PWM control unit, and the timing and bit control unit. The output signal is sent to the drive circuit of each power module to control the turn - on and turn - off of each module.

[0054] The SM control unit provides control signals for N - 1 power modules that need to be in the through state, collectively referred to as SM signals. The PWM control unit provides a PWM signal with a duty cycle of D. The timing and bit control unit provides a binary - coded signal to control the cycle of the PWM signal output. The timing and bit control principle is to set the counting function f = 2 n , n increments by 1 from 0 every time interval T. The time interval T is the time interval for the PWM signal to switch from the previous power module to the next power module. n increments from 0 to 5 to complete one cycle. The counting function f is converted into a six - bit binary code as the cyclic control signal output by the timing and bit control unit.

[0055] The SM signal and the PWM signal are aggregated and input into the cyclic controller. The cyclic controller outputs the SM signal and the PWM signal according to a certain control rule based on the cyclic control signal.

[0056] When the first power module works in the PWM modulation state, the signal corresponding to the PWM signal at this time is "1", otherwise it is "0". For example, when the first power module works in the PWM modulation state, the counting function f is "2 0 ", which is converted into a binary code of "000001", that is, the cyclic control signal output by the timing and bit control unit is "000001". The cyclic controller outputs the PWM signal as the first signal according to this signal, and the remaining 5 signals are SM signals; after a time interval T, the PWM module rotates to the second power module. At this time, the counting function f is "2 1 ", which is converted into a binary code of "000010", and the output of the timing and bit control unit is the cyclic control signal of "000010". The cyclic controller outputs the PWM signal as the second signal according to this signal, and the remaining 5 signals are SM signals; and so on. Finally, the counting function f becomes 2 5 , and the cyclic control signal becomes "100000", completing one cycle.

[0057] It should be noted that in the above solution, the N-bit binary coded signal refers to a signal composed of N binary bits, and each bit can be "0" or "1". For example, for 6 power modules, the cyclic control signal can be "000001", "000010", etc.

[0058] It should also be noted that in the above solution, each bit corresponds to a power module, which means that each bit of the cyclic control signal corresponds to a power module. For example, for 6 power modules, "000001" indicates that the current first power module is a PWM module, and "000010" indicates that the current second power module is a PWM module. The power module corresponding to the bit with a value of "1" in the cyclic control signal is the power module currently in the PWM modulation state.

[0059] Further preferably, in step S2, voltage sampling is performed according to the voltage sensor voltage signal at the direct output end of the PSM high-voltage power supply and the set acquisition mechanism to obtain a sampled voltage signal, including:

[0060] Determine the sampling moment through the PWM signal in the signal generation module, and detect the rising edge or falling edge of the PWM signal in an interrupt manner;

[0061] After detecting the rising edge or falling edge of the PWM signal, delay for a preset time t to ensure that the switching tube of the target power module to be detected is in the on or off state;

[0062]

[0063] In the formula, D is the duty cycle of the PWM signal, and f is the switching frequency;

[0064] Read the analog voltage signal of the voltage sensor and convert it into a digital voltage value;

[0065] Among them, the digital voltage value includes the sampled voltage signal U2 collected when the rising edge is detected, and the sampled voltage signal U1 collected when the falling edge is detected.

[0066] Furthermore, the difference between the sampled voltage signals U2 and U1 at the direct output end of the PSM high-voltage power supply is used as the voltage value of the target power module.

[0067] Combined with Figure 5As shown in the figure, in combination with the PSM principle, take the voltage U2 at the direct output terminal of the PSM high-voltage power supply collected during the high-level time (rising-edge delay t) when the PWM power supply module (referring to the power supply module in the PWM modulation state) is working. At this time, the measured voltage U2 is the sum of the voltages of all N series-connected power supply modules. Take the voltage U1 at the direct output terminal of the PSM high-voltage power supply collected during the low-level time (falling-edge delay t) when the PWM power supply module is working. At this time, the measured voltage U1 is the sum of the voltages of the remaining N - 1 series-connected power supply modules except the PWM power supply module. The difference between U2 and U1 is the voltage value corresponding to this PWM power supply module.

[0068] In this embodiment, the voltage acquisition mechanism is as follows:

[0069] Detect the rising edge of the PWM signal through the interrupt method, and after detecting the rising edge, delay for t (D / 2f) to ensure the stable conduction of the switching tube, and use the ADC to convert the voltage sensor signal into a voltage value. Similarly, detect the falling edge of the PWM signal through the interrupt method, and after detecting the falling edge, delay for t (D / 2f) to ensure the stable cut-off of the switching tube, and then use the ADC to convert the voltage sensor signal into a voltage value. Finally, store the read voltage value.

[0070] Further preferably, the present invention further includes a power supply over-voltage and under-voltage protection method, which further includes: comparing the calculated voltage value of the target power supply module with the preset over-voltage and under-voltage thresholds. If the voltage value of the power supply module exceeds the preset over-voltage or under-voltage threshold, then perform the over-voltage or under-voltage protection action.

[0071] Furthermore, the over-voltage or under-voltage protection action includes: blocking the trigger signal of the IGBT (Insulated Gate Bipolar Transistor) of the power supply module switch tube, and turning on the corresponding over-voltage or under-voltage indicator light.

[0072] Combined with Figure 6 As shown in the figure, according to the above solution of the present invention, in specific implementation, it includes the following feasible process steps:

[0073] Step 1: Determine the power supply module currently in the PWM modulation state according to the PWM module cyclic control strategy, that is, the currently detected power supply module.

[0074] Step 2: Collect the voltage values U1 and U2.

[0075] Step 3: Calculate the voltage value to obtain the voltage of the current power supply module.

[0076] Step 4: Perform overvoltage and undervoltage threshold judgment. If the measured module voltage value exceeds the set overvoltage or undervoltage threshold, the power controller will lock the trigger signal of the switching tube IGBT for protection and turn on the corresponding over / undervoltage indicator light. If the measured module voltage value is within the set over / undervoltage threshold, it indicates that the power module is working normally.

[0077] Step 5: The PWM signal loops to the next power module, and the above steps are repeated to detect all power modules in turn.

[0078] According to the above embodiments of the present invention, the technical principle of the present invention is to combine the pulse width modulation (PWM) technology with the stepped modulation (SM) technology. The present invention uses the PWM module cyclic control strategy to set each power module to the PWM modulation state in turn, and detects the voltage change at the direct output end of the PSM high-voltage power supply through a single voltage sensor. Since there is voltage pulsation in the direct output voltage of the PSM high-voltage power supply under the PSM technology modulation, and the voltage pulsation magnitude is the power module voltage value, the voltage values sampled at the high level and low level of the PWM signal will be different. By calculating the difference between these two sampled values, the voltage value of the target power module currently in the PWM modulation state can be obtained.

[0079] Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in hardware or software depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of this application.

[0080] In addition, each functional module in the various embodiments of the present application can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit.

[0081] The above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present application.

Claims

1. A voltage detection method for a single voltage sensor module of a PSM high-voltage power supply, characterized in that, The PSM high-voltage power supply includes a number of power modules and a signal generation module, and the method includes: Determining a target power module that is currently in the PWM modulation state according to the PWM module cyclic control strategy; Performing voltage sampling according to the voltage signal of the voltage sensor at the direct output end of the PSM high-voltage power supply and the set voltage acquisition mechanism to obtain a sampled voltage signal; Determining the voltage value of the target power module according to the sampled voltage signal; The PWM module cyclically traverses each power module in the PSM high-voltage power supply and sequentially detects the voltage of each power module.

2. The voltage detection method of the single voltage sensor module of a PSM high-voltage power supply according to claim 1, characterized in that, The voltage sensor is connected in parallel at the direct output end of the PSM high-voltage power supply, and one voltage sensor is provided.

3. The voltage detection method of the single voltage sensor module of a PSM high-voltage power supply according to claim 1, characterized in that, The determining a target power module that is currently in the PWM modulation state according to the PWM module cyclic control strategy includes: Setting N - 1 of the N power modules to the direct-through state, where N is an integer greater than 1, and setting the remaining one to the PWM modulation state, and controlling the cyclic switching of the direct-through signal and the PWM signal among the power modules through the PWM module cyclic control unit; Reading the cyclic control signal of the PWM module cyclic control unit to determine the target power module that is currently in the PWM modulation state.

4. The voltage detection method of a single voltage sensor module of a PSM high-voltage power supply according to claim 3, characterized in that, Reading the cyclic control signal of the PWM module cyclic control unit to determine the target power module that is currently in the PWM modulation state includes: The cyclic control signal of the PWM module cyclic control unit is an N-bit binary encoded signal, each bit corresponding to a power module, and the power module corresponding to the bit with a value of "1" in the output signal is the target power module.

5. The voltage detection method of a single voltage sensor module of a PSM high-voltage power supply according to claim 4, characterized in that, The performing voltage sampling according to the voltage signal of the direct output end of the PSM high-voltage power supply and the set acquisition mechanism to obtain a sampled voltage signal includes: Determining the sampling moment through the PWM signal in the signal generation module, and detecting the rising edge or falling edge of the PWM signal in an interrupt manner; After detecting the rising edge or falling edge of the PWM signal, delaying for a time t to ensure that the switching tube of the detected power module is in the on or off state; Reading the analog voltage signal of the voltage sensor and converting it into a digital voltage value; Wherein, the digital voltage value includes the sampled voltage signal U2 collected after delaying for t when the rising edge of the PWM signal is detected, and the sampled voltage signal U1 collected after delaying for t when the falling edge of the PWM signal is detected.

6. The voltage detection method of the single voltage sensor module of the PSM high-voltage power supply according to claim 5, characterized in that, The determining the voltage value of the target power module according to the sampled voltage signal includes: Taking the difference between the sampled voltages U2 and U1 of the voltage signal at the direct output end of the PSM high-voltage power supply as the voltage value of the target power module.

7. A method for detecting the voltage of a single voltage sensor module of a PSM high-voltage power supply according to claim 1, characterized in that, The method further includes: Comparing the calculated voltage value with the preset overvoltage and undervoltage thresholds according to the voltage value of the target power module, and if the voltage value of the power module exceeds the preset overvoltage or undervoltage threshold, performing an overvoltage or undervoltage protection action.

8. The voltage detection method of the single voltage sensor module of a PSM high-voltage power supply according to claim 7, characterized in that, The overvoltage or undervoltage protection action includes: Blocking the IGBT trigger signal of the switching tube; Turning on the corresponding overvoltage or undervoltage indicator light.

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