A power system load simulation control method

Abstract

This invention discloses a power system load simulation and control method, which loads the majority of the load value using a resistive load and a small portion of the dynamic load value using an electronic load. This satisfies the requirements for capacity, accuracy, and dynamism. By physically combining the resistive and electronic loads, with the resistive load as the primary load, capacity and economy requirements are met; while the electronic load serves as a secondary load, high accuracy and high dynamism performance requirements are met.

Description

Technical Field

[0001] This invention belongs to the field of aircraft ground testing technology, and in particular relates to a power system load simulation loading control method. Background Art

[0002] There are two main types of load simulation methods for power supply systems: traditional resistive loads and electronic loads.

[0003] Resistive loads use relays to control the series and parallel connection of different resistors to change the current. Their load values ​​are discontinuous, with fixed load levels, and they generally employ open-loop control. The equipment has poor continuity and accuracy, and weak dynamic performance, but it is inexpensive, making it quite economical for high-power loads.

[0004] Electronic loads, through the control of power electronic devices and the use of closed-loop control, precisely adjust the load current. They feature high precision, programmability, excellent dynamic performance, and diverse control modes. However, they are expensive and less economical for high-power loads. Summary of the Invention

[0005] Purpose of the invention

[0006] To address the shortcomings of existing power system load simulation methods, this invention provides a power system load simulation loading control method.

[0007] Invention Technology Solutions

[0008] A power system load simulation control method includes the following steps:

[0009] s1. Obtain the required load value. If it is different from the value obtained last time, proceed to step s2. If it is the same as the value obtained last time, exit.

[0010] s2. Load calculation and allocation to resistive and electronic loads: A% of the total capacity of the electronic load is used for allocation. When the load value does not exceed A% of the total capacity of the electronic load, the electronic load is used directly. When the load value exceeds A% of the capacity of the electronic load, the excess part is loaded using the resistive load. Finally, the resistive load level and the electronic load value are obtained.

[0011] s3. Resistive load loading, electronic load loading:

[0012] s3.1 When applying resistive load, if the calculated resistive load value is not equal to the current actual resistive load value, compare the difference between the calculated resistive load loading / unloading position and the current actual resistive load loading / unloading position, and load / unload the positions with differences to make the current actual resistive load position consistent with the calculated resistive load position; if the calculated resistive load value is equal to the current actual resistive load value, then do nothing and proceed to step 3.2.

[0013] s3.2 If the calculated electronic load value is not equal to the current actual electronic load value, then perform electronic load loading; if the calculated electronic load value is equal to the current actual electronic load value, then proceed to step s3.3.

[0014] s3.3 Check the resistive load loading command. If the resistive load loading command has not been executed, re-execute it. If it has been executed, proceed to step 3.4.

[0015] s3.4 Determine whether electronic load loading has been executed. If not, re-execute; if already executed, load loading is complete.

[0016] s4. Load closed-loop control:

[0017] s4.1 reads the total load value;

[0018] s4.2 Confirm whether the resistive load has been fully applied;

[0019] s4.3 Read the current resistive load measurement value. If the current resistive load measurement value is greater than the total load value, reduce the resistive load load value. The amount of reduction in the resistive load load value is equal to the current resistive load measurement value plus the electronic load capacity A% and then subtracted from the total load value. Then proceed to step s4.2. If the total load value is greater than or equal to the resistive load measurement value, proceed to step s4.4.

[0020] s4.4 Determine whether the total load value - the current resistive load measurement value is less than or equal to the electronic load capacity. If yes, adjust the electronic load so that the total load value - the current resistive load measurement value equals the electronic load load value, and then load the electronic load. If no, increase the resistive load load value by an amount equal to the total load value minus the current resistive load measurement value minus the electronic load capacity A%, and then proceed to step s4.2.

[0021] s5: Repeat process s1 to s4.

[0022] Preferably, when loading and unloading resistive loads, the larger speed setting should be used.

[0023] Preferably, A% is 45%.

[0024] Preferably, in step s3, when choosing between increasing and decreasing the load, the load should be decreased first; when adding or unloading electronic loads and resistive loads, the resistive load should be added or unloaded first.

[0025] Preferably, the actual resistive load value is measured by a current and voltage measurement module, which uses current and voltage sensors.

[0026] Preferably, the load calculation, resistive load loading, electronic load loading, and load closed-loop control are performed by a control computer. The control computer can read the measured values ​​of the current and voltage measurement modules, and the electronic load can receive the loading command from the control computer. The resistive load can receive the loading command from the control computer and control the parallel relationship of the relay switching resistors.

[0027] Preferably, the ratio of resistive load to electronic load is ≥4:1.

[0028] Preferably, the resistive load is based on an initial value of 0.25A at the nominal voltage, and is divided into several levels in geometric multiples of 2.

[0029] Preferably, the number of current and voltage acquisition modules is no less than 3, and the acquisition range of the current and voltage sensor modules is 1 / 3, 2 / 3 and full scale of the rated load value of the resistive load box.

[0030] Preferably, the resistive load is in constant resistance mode; the electronic load has constant resistance mode, constant current mode, and constant power mode; the control computer has constant resistance mode, constant current mode, and constant power mode control modes. In constant resistance mode control mode, the electronic load is set to constant resistance mode, and the calculated resistive load value + calculated electronic load value = total set value; in constant current mode control mode, the electronic load is set to constant current mode, and the load closed-loop control feedback signal is the measured value of the current sensor that measures the actual resistive load value; in constant power mode control mode, the electronic load is set to constant power mode, and the load closed-loop control feedback signal is calculated using P = U*I.

[0031] Advantages of this invention:

[0032] (1) Physically combine resistive loads and electronic loads, with resistive loads as the main component to meet capacity and economic requirements; and electronic loads as the auxiliary component to meet high precision and high dynamic performance requirements.

[0033] (2) This method performs real-time load distribution calculation and parameter closed-loop control, distributes the load to resistive load and electronic load, and makes periodic corrections to meet the loading requirements of dynamic, high precision and programmability, effectively meeting the load simulation requirements of the power system of the test equipment such as aircraft. Attached Figure Description

[0034] Figure 1 To load the control flow diagram.

[0035] Figure 2 This is a perspective view of the external shape and installation position of the integrated pontoon-tail structure of the present invention.

[0036] Figure 3 Flowchart for load allocation calculation.

[0037] Figure 4 This is a flowchart for loading resistive and electronic loads.

[0038] Figure 5 This is a flowchart of the load closed-loop control. Detailed Implementation

[0039] The present invention is achieved through the following technical solution.

[0040] A power system load simulation control method includes the following steps:

[0041] s1: Obtain the required load value;

[0042] s2: Load calculation, allocation to resistive load and electronic load;

[0043] s3: Resistive load loading, electronic load loading;

[0044] s4: Load closed-loop control;

[0045] s5: Repeat process s1 to s4.

[0046] In step s1, the loading value is updated at a frequency of not less than 2Hz or the actual cycle time from s1 to s4.

[0047] In step s2, only the current load value is used as input, without referring to the previous load value, and the load is allocated according to the principle of prioritizing the largest load level. Specifically, when selecting the loading / unloading level for resistive loads, the largest level is prioritized (the largest level is prioritized during loading / unloading). See the load allocation calculation flowchart below. Figure 3 The electronic load has a 10% capacity reserve. Half of the remaining 90% capacity (45% of the total capacity) is allocated. When the load value does not exceed 45% of the electronic load capacity, the electronic load is used directly. When the load value exceeds 45% of the electronic load capacity, the excess portion is loaded using a resistive load (selecting the load level from highest to lowest). Due to the variability of resistive loads, there may be cases where the load value cannot be fully loaded. In these cases, the unloaded portion of the resistive load is added to the 45% electronic load and then loaded using the electronic load. This process ultimately determines the resistive load level and the electronic load value.

[0048] In step s3, add / unload commands are sent to the resistive and electronic loads via the bus. Specifically, when adding or reducing the load, load reduction is prioritized; when adding or unloading electronic or resistive loads, resistive load addition or unloading takes precedence. See the logic flowchart below. Figure 4First, resistive load is applied. If the resistive load value is not equal to the current resistive load value, the unloaded gear is unloaded first, and then the added gear is applied, prioritizing the larger gear during the loading and unloading process. If the calculated resistive load value is equal to the current actual resistive load value, resistive load application is performed; if the electronic load value is not equal to the current electronic load value, electronic load application is performed. If the electronic load value is equal to the current electronic load value, the next step is to check the resistive load application command. If the loading command has not been executed, it is re-executed; if it is executed, the next step is to determine whether the electronic load application has been executed. If it has not been executed, it is re-executed; if it is executed, the load application is complete.

[0049] In step s4, the actual load value of the resistive load is calculated based on the feedback values ​​collected by the voltage and current sensors. The total load value is then corrected by updating the load value of the electronic load to meet the requirements of accuracy and dynamics. The specific process is as follows: It should be detected whether the resistive load loading is complete. After loading is complete, wait 100ms or set this parameter according to the power supply's regulation capability. After the loaded current enters a relatively stable period, the electronic load is adjusted. See the load closed-loop control flowchart. Figure 5 The process begins by reading the total load value and the resistive load measurement value. The first step confirms whether the resistive load has been fully loaded. After waiting 100ms, the current resistive load measurement value (sensor measurement value) is read. If the current resistive load measurement value is greater than the total load value, the resistive load value is reduced (the reduction equals the current resistive load measurement value plus 45% of the electronic load capacity minus the total load value), and the closed-loop process is restarted. If the total load value is greater than or equal to the resistive load measurement value, the process proceeds to the next step. The total load value minus the resistive load measurement value should be less than the electronic load capacity. If it is greater than the electronic load capacity, the resistive load value is increased (the increase equals the total load value minus the resistive load measurement value minus 45% of the electronic load capacity), and the closed-loop process is restarted. If the total load value minus the resistive load measurement value is less than or equal to the electronic load capacity, the electronic load adjustment phase begins. The total load value minus the resistive load measurement value equals the electronic load value. The electronic load is then loaded.

[0050] In this embodiment, a control computer is used for load calculation, resistive load loading, electronic load loading, and load closed-loop control. The control computer can read the measured values ​​from the current and voltage measurement modules. The measured load values ​​of the resistive load are acquired through the current and voltage acquisition modules. After the control computer calculates the load compensation value, compensation is performed through the electronic load to complete the closed-loop control. This meets the requirements for capacity, accuracy, and dynamic performance.

[0051] The control computer includes a monitor and a computer. It has the ability to communicate with current and voltage acquisition modules, electronic loads, and resistive loads; it also has the ability to distribute loads and drive electronic loads and resistive loads.

[0052] The control computer should have multiple load control modes and closed-loop dynamic adjustment control capabilities, and perform closed-loop calibration of the load value at a frequency of not less than 2Hz to meet the dynamic requirements of the device.

[0053] The electronic load receives loading commands from the control computer and has control modes such as current, resistance, and power.

[0054] The resistive load receives the loading command from the control computer and controls the relay to switch the parallel relationship of the resistors. Each channel corresponds to one resistor. By connecting or disconnecting the resistor, the current is increased or decreased.

[0055] The ratio of resistive load to electronic load is ≥4:1, or the electronic load capacity is configured according to the capacity of the dynamic load in actual working conditions; (resistive load capacity + 45% of electronic load capacity) ≥ load capacity requirement; by combining resistive load as the main component and electronic load as the auxiliary component, the capacity and economic requirements of the device are met.

[0056] The resistive load is based on an initial value of 0.25A at the nominal voltage, and is divided into levels in geometric multiples of 2 (0.25A, 1A, 2A, 4A, 8A, etc.). The current and voltage acquisition module for the resistive load should use multiple sensors for acquisition and reduce acquisition errors by comparing and filtering data sources to meet the high precision requirements of the device.

[0057] The current and voltage acquisition module includes a voltage sensor, a current sensor, an analog-to-digital converter, and a communication module, which sends the voltage and current information of the resistive load to the control computer.

[0058] The number of current and voltage acquisition modules should be no less than 3. The acquisition range of the current and voltage sensor modules should be 1 / 3, 2 / 3, and full scale of the rated load value of the resistive load box, or the measurement range should be segmented according to the number of sensors and the actual distribution of measured values. After acquiring the acquired values, the sensor values ​​with a range greater than the acquired value and the smaller range should be accepted.

[0059] The control computer should have load control capabilities, including constant resistance, constant current, and constant power modes. The control modes are as follows:

[0060] Constant resistance mode: The resistive load itself is in constant resistance mode, and the electronic load is also set to constant resistance mode. The calculated resistive load setting value + electronic load setting value = total setting value. Closed-loop load control can be turned off. If not turned off, closed-loop control is performed using R = U / I.

[0061] Constant current mode: The electronic load is set to constant current mode, and the closed-loop load control feedback signal is a resistive load current sensor.

[0062] Constant power mode: The electronic load is set to constant power mode, and the closed-loop load control feedback signal is calculated using P = U * I.

[0063] The scope of protection of this invention is not limited to the embodiments described above. Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its scope. If such modifications and variations fall within the scope of the claims of this invention and their equivalents, then the intent of this invention also includes these modifications and variations.

Claims

1. A power system load simulation loading control method, characterized in that, Includes the following steps: s1. Obtain the required load value. If it is different from the value obtained last time, proceed to step s2. If it is the same as the value obtained last time, exit. s2. Load calculation and allocation to resistive and electronic loads: A% of the total capacity of the electronic load is used for allocation. When the load value does not exceed A% of the total capacity of the electronic load, the electronic load is used directly. When the load value exceeds A% of the capacity of the electronic load, the excess part is loaded using the resistive load. Finally, the resistive load level and the electronic load value are obtained. s3. Resistive load loading, electronic load loading: s3.1 When applying resistive load, if the calculated resistive load value is not equal to the current actual resistive load value, compare the difference between the calculated resistive load loading / unloading position and the current actual resistive load loading / unloading position, and load / unload the positions with differences to make the current actual resistive load position consistent with the calculated resistive load position; if the calculated resistive load value is equal to the current actual resistive load value, then do nothing and proceed to step 3.

2. s3.2 If the calculated electronic load value is not equal to the current actual electronic load value, then perform electronic load loading; if the calculated electronic load value is equal to the current actual electronic load value, then proceed to step s3.

3. s3.3 Check the resistive load loading command. If the resistive load loading command has not been executed, re-execute it. If it has been executed, proceed to step 3.

4. s3.4 Determine whether electronic load loading has been executed. If not, re-execute; if already executed, load loading is complete. s4. Load closed-loop control: s4.1 reads the total load value; s4.2 Confirm whether the resistive load has been fully applied; s4.3 Read the current resistive load measurement value. If the current resistive load measurement value is greater than the total load value, reduce the resistive load load value. The amount of reduction in the resistive load load value is equal to the current resistive load measurement value plus the electronic load capacity A% and then subtracted from the total load value. Then proceed to step s4.

2. If the total load value is greater than or equal to the resistive load measurement value, proceed to step s4.

4. s4.4 Determine whether the total load value - the current resistive load measurement value is less than or equal to the electronic load capacity. If yes, adjust the electronic load so that the total load value - the current resistive load measurement value equals the electronic load load value, and then load the electronic load. If no, increase the resistive load load value by an amount equal to the total load value minus the current resistive load measurement value minus the electronic load capacity A%, and then proceed to step s4.

2. s5: Repeat process s1 to s4.

2. The power system load simulation loading control method as described in claim 1, characterized in that, When loading and unloading resistive loads, prioritize using the higher speed setting.

3. The power system load simulation loading control method as described in claim 1, characterized in that, A% is 45%.

4. The power system load simulation loading control method as described in claim 1, characterized in that, In step s3, when choosing between increasing and decreasing the load, the load should be decreased first. When adding or unloading electronic loads and resistive loads, the resistive load should be added or unloaded first.

5. The power system load simulation loading control method as described in claim 1, characterized in that, The actual resistive load value is measured by the current and voltage measurement module, which uses current and voltage sensors.

6. The power system load simulation loading control method as described in claim 5, characterized in that, The control computer performs load calculations, resistive load loading, electronic load loading, and load closed-loop control. The control computer can read the measured values ​​from the current and voltage measurement modules, and the electronic load can receive the loading commands from the control computer. The resistive load can receive the loading commands from the control computer and control the parallel connection relationship of the relay switching resistors.

7. The power system load simulation loading control method as described in claim 1, characterized in that, The ratio of resistive load to electronic load is ≥4:

1.

8. The power system load simulation loading control method as described in claim 1, characterized in that, The resistive load is based on an initial value of 0.25A at the nominal voltage, and is divided into several levels in geometric multiples of 2.

9. The power system load simulation loading control method as described in claim 5, characterized in that, The number of current and voltage acquisition modules is no less than 3, and the acquisition range of the current and voltage sensor modules is 1 / 3, 2 / 3 and full scale of the rated load value of the resistive load box.

10. The power system load simulation loading control method as described in claim 6, characterized in that, The resistive load operates in constant resistance mode; the electronic load has constant resistance, constant current, and constant power modes; the control computer has constant resistance, constant current, and constant power control modes. In constant resistance mode, the electronic load is set to constant resistance, and the calculated resistive load value + calculated electronic load value = total set value. In constant current mode, the electronic load is set to constant current, and the load closed-loop control feedback signal is the measured value of the current sensor that measures the actual resistive load value. In constant power mode, the electronic load is set to constant power, and the load closed-loop control feedback signal is calculated using P = U * I.

Images