Direct-current linear adjustable load simulation device

Abstract

The utility model discloses a 28V direct-current linear adjustable load simulation device, which comprises a direct-current load and a monitoring branch, the direct-current load is connected with a contact of a tested product, the contact of the product is connected with a direct-current power supply, and an output end of the direct-current load is connected with a loop of the direct-current power supply. The linear change load current required by the test can be simulated in real time within a certain load current range, and diversified load test requirements are met. And a test curve graph can be generated, real-time monitoring of the linear change current is realized, the matching degree with a theoretical expected load current curve is verified, and the test convenience is improved. Based on the control logic, the 28V direct current linear adjustable load simulation device for load simulation can also realize a current compensation function, under the condition of a direct current resistive load test, the required load current is a fixed value, and when current deviation is caused by heating of the load, the size of the load can be finely adjusted in real time, and accurate matching of the load current is realized.

Description

TECHNICAL FIELD

[0001] The utility model relates to a 28V DC linear adjustable load simulation device. BACKGROUND

[0002] 28V DC contactor has a wide range of uses in the field of aviation, in order to ensure that the contactor used has reliable performance, it is necessary to carry out cycle test on the contactor, and the cycle test includes DC resistive load and DC motor load. When the contactor is subjected to durability cycle test, the contact-on and contact-off cycles need to be set, and the specified load current is applied to the main contact to check whether the product meets the design requirements specified in the standard.

[0003] The current of the DC resistive load test is generally constant, and the fixed gear is adjusted before the test, and the load resistance does not need to be changed in the test. However, due to the continuous heating of the load, there is a certain deviation between the actual load current and the set value, and manual adjustment is often time-consuming and laborious. The DC motor load test generally needs to connect 6 times the rated motor load and disconnect the rated motor load. The current of this kind of test is step-type change, and two groups of loads need to be adjusted in advance before the test. One group of load is 5 times the rated motor load, which is controlled by a control contactor to connect and cut off, and the other group of load is 1 times the rated motor load. The resistance values of these two loads do not need to be changed in the test. However, in the actual use of the aviation field, the load current often changes, and within a certain time range, it presents a linear change trend. In the load simulation test, the conventional load simulation method is to realize multiple step-type load current curves by controlling the on-off of multiple loads. Although the response speed is fast, there is still a certain difference from the actual linear current change. How to realize the linear change of the load in a more efficient way has become a technical problem to be solved in the experimental process. For example, CN117054873B discloses a four-motor loading test bed for electric drive system testing with strong applicability. A data acquisition and evaluation module is arranged in the test system to evaluate the experimental process. During the experiment, the three output powers, temperatures and vibration frequencies are tested for different types of motors, but the load control process depends on the internal system of the controller. UTILITY MODEL CONTENTS

[0004] To solve the above technical problems, the utility model provides a 28V DC linear adjustable load simulation device.

[0005] The utility model is realized by the following technical solutions.

[0006] The utility model provides a kind of 28V DC linear adjustable load simulation device;Including: DC load and monitoring branch, the DC load is connected with the contact of measured product, product contact is connected with DC power supply, the output end of DC load is connected with the loop of DC power supply;Through the direct connection of DC load and DC power supply, closed test loop can be quickly constructed, the stability and continuity of load current are ensured, meet high-precision current simulation demand.

[0007] The load branch includes: the load branch is composed of 4 parallel and same structure load branches, each load branch is controlled by a control contactor, a fixed high-power resistor and an adjustable slide rheostat are connected in series in each load branch, and the adjustable slide rheostat is used.

[0008] The current sensor and voltage sensor of the monitoring branch monitor the current of each branch in real time, and the synchronous acquisition of the coil voltage sensor can accurately feedback the load state, ensuring the accuracy and traceability of test data.

[0009] The data acquisition module is connected with the voltage sensor, current sensor and temperature sensor at the input end, and is connected with the touch screen through Modbus485 communication protocol at the output end; the data acquisition module realizes efficient integration and transmission of multi-sensor data through standard communication protocol, improves the response speed and control accuracy of the system, and supports remote monitoring and data recording.

[0010] The touch screen communicates with the data acquisition module and controller through Modbus485 communication protocol; as the core of human-computer interaction, the touch screen supports parameter setting, real-time data display and curve generation, simplifies the operation process and enhances the visualization and controllability of the test process.

[0011] The controller is connected with the stepper motor through the drive circuit at the output end, and receives the feedback signal of the touch screen at the input end; based on the closed-loop control logic of the feedback signal, the controller realizes accurate adjustment of the slide rheostat by driving the stepper motor, ensuring dynamic matching of load current and preset curve.

[0012] The on-off output module is connected with the touch screen at the input end, and is connected with the control contactor and coil control interface at the output end. Through the precise control of the on-off output module on the load control contactor and coil loop, the load can be quickly cut off in case of failure, improving the safety and reliability of the system.

[0013] The adjustable slide rheostat group is composed of a plurality of parallel adjustable slide rheostats, and the plurality of parallel adjustable slide rheostats are adjusted by the stepper motor.

[0014] The controller generates a pulse signal to drive the stepping motor according to preset proportional integral parameters, and receives a feedback signal of the contact current sensor for closed-loop regulation.

[0015] The temperature sensor is fixed to the heat dissipation surface of the high-power resistor and the slide rheostat, and the output end is connected with the data acquisition module.

[0016] The touch screen is provided with a parameter input module, a real-time data display area and a curve display area.

[0017] The control coil of the control contactor is connected with the output end of the on-off output module, and the load circuit is cut off in case of failure.

[0018] The load interface and the coil control interface are connected with the product contact and the load DC power supply, and are connected with the product coil and the coil power supply, forming a complete closed test system.

[0019] The beneficial effects of the utility model lie in that: within a certain load current range, the linearly changing load current required by the test can be simulated in real time, diversified load test requirements are realized, test curves can be generated, real-time monitoring of the linearly changing current is realized, the matching degree of the linearly changing current with the theoretically expected load current curve is verified, and the convenience of the test is improved, current compensation function can be realized, under the condition of DC resistive load test, the required load current is a fixed value, when the load causes current deviation due to heating, the load size can be adjusted in real time, and accurate matching of the load current is realized. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 It is a structural schematic view of the utility model. DETAILED DESCRIPTION

[0021] The technical scheme of the utility model will be further described below, but the scope of protection is not limited to the description.

[0022] The 28V DC linearly adjustable load simulation device mainly comprises a coil voltage sensor, a contact current sensor, a data acquisition module, an on-off output module, a touch screen, a stepping motor, a controller, a high-power resistor, a slide rheostat, a load control contactor, a temperature sensor and the like. The complete load simulation device is integrated in a vertical cabinet, and provides a load interface and a coil control interface externally. The load simulation device is connected to a contactor life durability cycle test circuit, and through setting of a load current curve and a coil pulse period, linearly adjustable load simulation test of main contacts can be realized.

[0023] The specific structure of the load simulation device is as follows: a voltage sensor is used to monitor the on and off of the coil, so as to realize the synchronization of the coil timing control and the load timing control. The load is composed of the same 4 paths, each of which is composed of a high-power resistor and 4 slide rheostats connected in parallel, and whether to access the load loop is controlled by the load control contactor. Four contact current sensors are used to monitor the change of the current of the four paths, so as to feedback the coincidence of the real-time current and the expected current. Each of the four slide rheostats is driven and adjusted by a screw rod controlled by a stepper motor. The controller communicates with the touch screen in real time through the MODBUS485 communication protocol, and controls the movement of the four stepper motors. The data acquisition module and the switching value output module are connected to the touch screen for communication. The touch screen can record and save the current of each branch and the coil voltage in real time, and generate a total load current curve. By setting the load current curve parameters and the coil pulse period through software, the control logic is generated to control the movement of the stepper motor in the form of PI control, so as to realize the linear regulation of the load current. The P parameter controls the driving speed of the stepper motor, and the I parameter controls the elimination of deviation. In the case of load over-temperature, control structure jamming, load current abnormality and other faults, the system can drive the switching value output module to issue corresponding instructions to control the load to be cut off, and issue alarm information.

[0024] Embodiment: The load simulation 28V DC linear adjustable load simulation device adopts a vertical cabinet structure, with movable casters at the bottom for easy movement. The touch screen interface is located in the middle of the front of the cabinet, facing the field of view of the human face, for easy human-computer interaction. A load interface and a coil control interface are provided on the side of the device. The device is powered by 220V AC. Considering load heat dissipation and control logic, the high-power resistor is located at the top of the cabinet, and the slide rheostat and the stepper motor screw control part are located at the bottom of the cabinet. The cabinet adopts a side-in and back-out cooling mode. The temperature of the air outlet of the heat core part is monitored by a temperature sensor.

[0025] During use, the load interface is connected to the main contact load test loop, and the coil control interface is connected to the coil loop. After connecting the power supply of the device, the coil on-off time, cycle number, load current curve are set on the touch screen control interface, and the start test button is clicked. The load simulation 28V DC linear adjustable load simulation device can carry out linear adjustable load simulation test according to the set current curve.

[0026] In the experiment overload, the voltage sensor is used to monitor the coil voltage, and the on-off time sequence cycle of the product is logically judged by the coil voltage.

[0027] Current sensor: contact current sensor is used to monitor the current of the main contact loop, judge the on-off logic of the contact, and feedback the load current.

[0028] Temperature sensor: used to monitor the load temperature, when the load temperature exceeds the limit, send alarm information or cut off the load circuit.

[0029] Data acquisition module: through MODBUS 485 communication protocol with touch screen data exchange, real-time transmission of voltage sensor, current sensor, temperature sensor acquisition information.

[0030] Touch screen: through the man-machine interface to realize the interactive function, is the core mechanism of the load simulation 28V DC linear adjustable load simulation device, real-time communication with input and output module, real-time record of current, voltage, temperature information, and generate curve through the display interface. Through the software setting, the switch output module generates coil pulse, controls the coil timing, drives the controller to adjust the load.

[0031] DC load: DC load is composed of high-power resistor, slide rheostat and load control contactor, the load is divided into 4 identical branches, each branch is controlled by load control contactor, the load is composed of fixed part and adjustable part in series, the fixed part is 4.2kW / 0.186Ω high-power resistor, the adjustable part is composed of 4 2.7kW / 3Ω slide rheostats in parallel, the slide rod is controlled by step motor screw to adjust uniformly. The current regulation range of each branch is 30A-150A, the total load can realize any current within 120A-600A under 28V DC regulation.

[0032] Step motor and controller: set the load curve current value on the touch screen interface, drive the step motor by the controller to realize the periodic motion, realize the linear regulation of the load. According to the load current change rate, determine the PI control mode, control one step motor or all step motors to participate in load regulation. When the current is set to a constant value, combined with the feedback information of current sensor, the step motor can make real-time accurate fine adjustment near the set value.

[0033] DC power supply and test product: the load simulation 28V DC linear adjustable load simulation device is connected with the product contact and load DC power supply through the load interface, and connected with the product coil and coil power supply through the coil control interface, forming a complete closed test system.

Claims

1. A 28V DC linear adjustable load simulator, characterized by, The application relates to a DC load and monitoring branch circuit. The load branch circuit comprises four parallel load branch circuits with the same structure, each of which is controlled by a control contactor, a fixed high-power resistor and an adjustable slide rheostat are connected in series in each load branch circuit. The monitoring branch circuit comprises: a current sensor connected in series in each load branch circuit; a voltage sensor connected with a product coil; a data acquisition module with input ends connected with the voltage sensor, the current sensor and a temperature sensor and an output end connected with a touch screen through a Modbus485 communication protocol; the touch screen is bidirectionally connected with the data acquisition module and a controller through the Modbus485 communication protocol; the controller is connected with a stepping motor through a driving circuit and receives feedback signals from the touch screen; a switch output module is connected with the touch screen and connected with a control contactor and a coil control interface. The adjustable slide rheostat group is composed of multiple parallel adjustable slide rheostats which are adjusted by a stepping motor.

2. The 28 volt DC linear adjustable load simulation device of claim 1, wherein: The controller generates a pulse signal to drive the stepping motor through preset proportional-integral parameters and receives feedback signals from a contact current sensor for closed-loop regulation.

3. The 28 volt DC linear adjustable load simulation device of claim 1, wherein: The temperature sensor is fixed on the heat dissipation surface of the high-power resistor and the slide rheostat and is connected with the data acquisition module.

4. The 28 volt DC linear adjustable load simulation device of claim 1, wherein: The touch screen is provided with a parameter input module, a real-time data display area and a curve display area.

5. The 28 volt DC linear adjustable load simulation device of claim 1, wherein: The control coil of the control contactor is connected with the output end of the switch output module to cut off the load circuit in case of failure.

6. The 28 volt DC linear adjustable load simulation device of claim 1, wherein: The load interface and the coil control interface adopt industrial standard terminals.

7. The 28V DC linear adjustable load simulation device as described in claim 1, characterized in that: ​

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