Integrated alternating current power dynamometer

Abstract

The utility model discloses an integrated AC electric dynamometer comprising a cabinet, the cabinet is internally provided with an AC motor, an inverter, a dynamometer measurement control unit and a dynamometer state monitoring unit, the cabinet is internally provided with a plurality of metal separator plates, and the plurality of metal separator plates divide the space in the cabinet into a plurality of relatively independent accommodation spaces. The alternating current motor, the inverter, the dynamometer measurement control unit and the dynamometer state monitoring unit are all located in different containing spaces, and the alternating current motor, the inverter and the dynamometer measurement control unit are sequentially arranged in the case from bottom to top in the vertical direction. According to the scheme, electromagnetic interference can be reduced, measurement stability is improved, cable length is reduced, and manufacturing cost is reduced.

Description

Technical Field

[0001] This utility model relates to the field of power system testing technology, specifically to an integrated AC power dynamometer. Background Technology

[0002] A dynamometer is a testing device used to measure key performance parameters such as output power, torque, and speed of power equipment (such as engines, electric motors, and turbines). An AC-powered dynamometer is a device that uses an AC motor as its core, controlled by an AC variable frequency speed control system. It utilizes the AC motor to convert mechanical energy into electrical energy to measure parameters such as output power, speed, and torque of the power machinery, and can also achieve energy feedback to the power grid. A dynamometer generally consists of an AC motor, an inverter, a dynamometer measurement and control unit, and a dynamometer status monitoring unit. When the AC motor is running, its output mechanical energy drives the rotor of the dynamometer to rotate. Inside the dynamometer, mechanical energy is converted into electrical energy or generates electromagnetic resistance to counteract the mechanical energy through electromagnetic induction. For AC-powered dynamometers, braking torque is generated based on the principle of electromagnetic induction. During operation, the power machinery being tested drives the AC motor rotor to rotate. The rotor moves in the stator magnetic field, and according to Faraday's law of electromagnetic induction, the rotor conductors generate induced electromotive force and current. These induced currents and the stator magnetic field interact to form an Ampere force, which is opposite to the direction of rotor rotation, thereby generating a braking torque.

[0003] With the rapid development of various components in dynamometers, such as advancements in sensor technology, the measurement accuracy of electric dynamometers has been significantly improved. High-precision torque and speed sensors can accurately measure minute changes. Advances in signal processing technology have also reduced measurement errors, making measurement results more accurate and reliable. Based on computer control systems and advanced algorithms, electric dynamometers can automatically load, adjust, and diagnose faults. They can also achieve remote monitoring and data transmission through network communication, facilitating centralized management and remote operation, and improving testing efficiency and convenience. However, the dynamometer systems of existing testing and inspection equipment are complex, and the difficulty in system integration leads to poor equipment consistency. The connections between systems involve both analog and digital signals, resulting in significant electromagnetic interference and poor control and measurement stability. The numerous and long cables and high circuit losses contribute to the low efficiency and high cost of electric dynamometer systems. Utility Model Content

[0004] In view of the above-mentioned shortcomings of the existing technology, the technical problem to be solved by this utility model is: how to provide an integrated AC power dynamometer that can reduce electromagnetic interference, improve measurement stability, reduce cable length, and reduce manufacturing costs.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] An integrated AC dynamometer includes a chassis. Inside the chassis are an AC motor, an inverter, a dynamometer measurement and control unit, and a dynamometer status monitoring unit. The chassis contains multiple metal partitions that divide the space into several relatively independent accommodating spaces. The AC motor, inverter, dynamometer measurement and control unit, and dynamometer status monitoring unit are located in different accommodating spaces. The AC motor, inverter, and dynamometer measurement and control unit are arranged vertically from bottom to top within the chassis. Three first connection holes are provided on the metal partition between the AC motor and the inverter. First connectors are provided at the first connection holes. The three signal output terminals of the inverter and the three signal output terminals of the AC motor are respectively connected to the three first connectors, enabling electrical connection between the inverter and the AC motor through the three first connectors.

[0007] The working principle of this solution is as follows: This solution partitions the AC motor, inverter, dynamometer measurement and control unit, and dynamometer status monitoring unit into zones. Each zone is separated by a metal partition forming a shield. Through reflection and absorption, electromagnetic waves are prevented from entering one enclosure to another. Simultaneously, electromagnetic waves are shielded from propagating from inside the enclosure to the outside, and external electromagnetic waves are prevented from entering the enclosure, thus achieving electromagnetic shielding. This isolation of electromagnetic waves improves the problem of poor control and measurement stability caused by significant electromagnetic interference between systems containing both analog and digital signals. It avoids measurement inaccuracies caused by complex electromagnetic interference during dynamometer operation, thereby improving measurement accuracy.

[0008] On the other hand, this design arranges the AC motor, inverter, and dynamometer measurement and control unit vertically from bottom to top within the chassis. This arrangement plays a crucial role in the energy transfer process within the entire dynamometer. Firstly, this arrangement follows the direction of control signal transmission, significantly reducing cable length and manufacturing costs. Secondly, the reduced cable length also minimizes energy loss during dynamometer operation, increasing its power output and resolving the issues of energy consumption and manufacturing costs associated with dynamometers.

[0009] Preferably, the AC motor is provided with a speed sensor and a torque sensor, and a second connector is provided on a metal partition on one side of the AC motor. The output signal lines of the speed sensor and the torque sensor are connected to the signal input terminal of the dynamometer measurement and control unit after passing through the second connector.

[0010] Preferably, a DC power input port is provided on the top of the chassis, and the input terminal of the inverter is electrically connected to the DC power input port to provide DC power to the inverter through the DC power input port.

[0011] Preferably, a pressure sensor, a temperature sensor, and a vibration sensor are also provided inside the chassis. The pressure sensor is disposed on the surface of the AC motor, and the temperature sensor and the vibration sensor are disposed on the bottom of the chassis near the AC motor. The output signal lines of the pressure sensor, the temperature sensor, and the vibration sensor are all connected to the signal input terminal of the dynamometer measurement and control unit. Attached Figure Description

[0012] Appendix Figure 1 This is a schematic diagram of the measurement and control principle of the integrated AC power dynamometer of this utility model;

[0013] Appendix Figure 2 This is a schematic diagram of the integrated AC power dynamometer of this utility model.

[0014] Explanation of reference numerals in the attached diagram: 1. Pressure signal cable; 2. Dynamometer status monitoring unit; 3. Temperature signal cable; 4. Vibration signal cable; 5. Torque signal cable; 6. DC power input port; 7. Dynamometer measurement and control unit; 8. Inverter; 9. First connector; 10. AC motor; 11. Chassis; 12. Speed ​​signal cable. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this utility model provided in the accompanying drawings is not intended to limit the scope of the claimed utility model, but merely represents selected embodiments of the utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the scope of protection of this utility model.

[0016] This specific embodiment provides an integrated AC power dynamometer, as shown in the attached figure. Figure 1 and attached Figure 2As shown, the device includes a chassis 11, which houses an AC motor 10, an inverter 8, a dynamometer measurement and control unit 7, and a dynamometer status monitoring unit 2. A DC power input port 6 is located on the top of the chassis 11. The input terminal of the inverter 8 is electrically connected to the DC power input port 6 to provide DC power to the inverter 8 through the DC power input port 6.

[0017] The dynamometer measurement control unit 7 mainly receives start / stop signals for "dynamometer test" through two methods: manual operation input and automatic system triggering. When the operator needs to start the dynamometer test, he / she can send the "start dynamometer test" command directly through the human-machine interface (HMI) or host computer software such as a computer. The control unit then activates the sensor, loading device and inverter 8 link, and enters the data acquisition and load control state.

[0018] The dynamometer achieves real-time monitoring of power equipment through a collaborative mechanism of "dynamic loading and data feedback." Its core functions are jointly performed by the loading device, sensor system, control system, and data system. In the sensor monitoring stage, the dynamometer first collects key parameters such as torque, speed, and temperature in real time through sensors: the torque sensor converts mechanical deformation into electrical signals, the speed sensor captures the speed frequency, and other sensors monitor auxiliary parameters such as temperature and current. These analog signals are converted into digital signals by a data acquisition card (DAQ) and filtered to eliminate noise interference, ensuring data accuracy. Subsequently, the control system initiates closed-loop feedback regulation based on preset targets (such as constant speed or torque), dynamically adjusting the load on the loading device using a PID algorithm. Simultaneously, the software interface visualizes real-time data as dynamic curves or dashboards and continuously records historical data for performance analysis.

[0019] The dynamometer's measurement function is achieved through an integrated system of "dynamic loading - signal acquisition - closed-loop feedback." The dynamometer first applies a controllable load to the tested equipment via a loading device, simulating resistance under actual working conditions. Simultaneously, high-precision sensors acquire key parameters in real time—torque sensors convert the torsional deformation of the mechanical shaft into electrical signals, encoders or photoelectric sensors capture speed pulse signals, and auxiliary sensors such as temperature and vibration monitor the equipment's operating status. These raw signals are filtered, amplified, and converted from analog to digital by the data acquisition system to eliminate noise interference before being transmitted to the control system. Based on preset test targets, the system dynamically adjusts the output of the loading device using a PID algorithm, forming a closed-loop feedback to ensure stable measurement conditions. Subsequently, the core parameters (torque, speed) are calculated using the formula p=Tn / 9550 to obtain real-time power, and combined with efficiency analysis (output / input energy ratio), temperature rise curves, and other data, presented intuitively in the software interface as dynamic charts or digital instruments.

[0020] The dynamometer measurement and control unit 7 collects mechanical parameters such as torque and speed in real time through high-precision sensors. After filtering and analog-to-digital conversion by the data acquisition system, the data is compared with the user-set target values ​​(such as constant torque or dynamic speed curves), and the deviation is calculated using a PID control algorithm. The control unit generates control signals based on the calculation results, typically using pulse width modulation (PWM) signals. These signals are transmitted to the drive circuit of the inverter 8. The drive circuit of the inverter 8 adjusts the on and off times of the power switching devices according to the received control signals, thereby changing the voltage, frequency, or phase parameters of the inverter 8 output, achieving control of the tested equipment and bringing it to the preset operating state. Simultaneously, the inverter 8 feeds back real-time operating parameters (such as current and temperature) to the dynamometer measurement and control unit 7, forming a millisecond-level closed-loop feedback. Anti-interference design and communication optimization ensure the stability and timeliness of signal transmission, ultimately achieving precise maintenance of the target operating condition through dynamic adjustment. This completes the process of the dynamometer measurement and control unit adjusting the output of the inverter 8 in real time.

[0021] A DC power supply (such as a grid rectifier unit or energy storage device) provides a stable DC bus voltage to inverter 8. Inverter 8, according to the instructions of the dynamometer measurement control unit 7, converts the DC power into three-phase AC power with adjustable frequency and amplitude through PWM modulation, driving the AC motor 10 built into the dynamometer. At this time, the AC motor 10 of the dynamometer acts as a controllable load, mechanically connected to the device under test via a coupling, simulating torque or speed load under actual operating conditions. During the test, the dynamometer's sensors collect the output parameters of the device under test in real time. The control unit dynamically adjusts the output frequency and current of inverter 8 based on the target operating conditions, enabling AC motor 10 to accurately apply or absorb mechanical energy. When the device under test is in a generator state (such as motor deceleration braking), the AC motor 10 of the dynamometer switches to generator mode, and inverter 8 synchronously switches to rectification mode, converting the feedback AC power into DC power and sending it back to the bus for system use or feedback to the grid, achieving energy recycling.

[0022] In this specific embodiment, the chassis 11 is provided with multiple metal partitions, which divide the space inside the chassis 11 into multiple relatively independent accommodating spaces. The AC motor 10, inverter 8, dynamometer measurement and control unit 7, and dynamometer status monitoring unit 2 are all located in different accommodating spaces. The AC motor 10, inverter 8, and dynamometer measurement and control unit 7 are arranged vertically from bottom to top inside the chassis 11. Three first connection holes are provided on the metal partition between the AC motor 10 and the inverter 8, and first connectors 9 are provided at the first connection holes. The three signal output terminals of the inverter 8 are respectively connected to the three first connectors 9, and the three signal output terminals of the AC motor 10 are respectively connected to the three first connectors 9, so as to establish an electrical connection between the inverter 8 and the AC motor 10 through the three first connectors 9. Using the first connectors 9 to connect the AC motor 10 and the inverter 8 can reduce the length of the cables of the AC motor 10 and the inverter 8.

[0023] In this specific embodiment, a speed sensor and a torque sensor are provided on the AC motor 10, and a second connector is provided on a metal partition on one side of the AC motor 10. The output signal lines of the speed sensor and the torque sensor (as shown in the attached diagram) Figure 2 The speed signal cable 12 and torque signal cable 5 are connected to the signal input terminal of the dynamometer measurement and control unit 7 after passing through the second connector. The speed sensor is used to collect the speed of the AC motor 10, and the torque sensor is used to collect the torque of the AC motor 10. The collected speed and torque of the AC motor 10 are returned to the dynamometer measurement and control unit 7. The dynamometer measurement and control unit 7 controls the inverter 8 according to the obtained speed and torque of the AC motor 10, thereby realizing feedback regulation.

[0024] In this specific embodiment, a pressure sensor, a temperature sensor, and a vibration sensor are also provided inside the chassis 11. The pressure sensor is disposed on the surface of the AC motor 10, and the temperature sensor and vibration sensor are disposed on the bottom of the chassis 11 near the AC motor 10. The output signal lines of the pressure sensor, temperature sensor, and vibration sensor (as shown in the attached diagram) are connected. Figure 2 The pressure signal cable 1, temperature signal cable 3, and vibration signal cable 4 are all connected to the signal input terminal of the dynamometer measurement and control unit 7. The pressure sensor, temperature sensor, and vibration sensor are used to detect the pressure, temperature, and vibration inside the chassis 11, respectively, and the detected data are then sent to the dynamometer measurement and control unit 7.

[0025] The working principle of this scheme is as follows: This scheme partitions the AC motor 10, inverter 8, dynamometer measurement and control unit 7, and dynamometer status monitoring unit into zones. Each zone is separated by a metal partition forming a shield. Through reflection and absorption, electromagnetic waves are prevented from entering one enclosure from another, and electromagnetic waves are also shielded from propagating from inside the chassis 11 to the outside, while external electromagnetic waves are prevented from entering the chassis 11, thus achieving electromagnetic shielding. This isolation of electromagnetic waves improves the problem of poor control and measurement stability caused by significant electromagnetic interference between systems containing both analog and digital signals. It avoids measurement inaccuracies caused by complex electromagnetic interference during dynamometer operation, thereby improving measurement accuracy.

[0026] On the other hand, this design arranges the AC motor 10, inverter 8, and dynamometer measurement control unit 7 vertically from bottom to top within the chassis 11. This arrangement plays a crucial role in the energy transfer process of the entire dynamometer. Firstly, this arrangement follows the direction of control signal transmission, thus significantly reducing cable length and manufacturing costs. Secondly, the reduced cable length also decreases energy loss during dynamometer operation, increasing the dynamometer's power output and resolving the issues of energy consumption and manufacturing costs associated with dynamometers.

[0027] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model and not to limit the technical solutions. Those skilled in the art should understand that any modifications or equivalent substitutions to the technical solutions of this utility model that do not depart from the spirit and scope of this technical solution should be covered within the scope of the claims of this utility model.

Claims

1. An integrated AC power dynamometer, characterized in that, The device includes a chassis containing an AC motor, an inverter, a dynamometer measurement and control unit, and a dynamometer status monitoring unit. The chassis contains multiple metal partitions that divide the space into several relatively independent accommodating spaces. The AC motor, inverter, dynamometer measurement and control unit, and dynamometer status monitoring unit are located in different accommodating spaces, arranged vertically from bottom to top within the chassis. Three first connection holes are provided on the metal partition between the AC motor and the inverter, and first connectors are provided at these holes. The three signal output terminals of the inverter and the AC motor are respectively connected to these three first connectors, enabling electrical connection between the inverter and the AC motor through these three first connectors.

2. The integrated AC power dynamometer according to claim 1, characterized in that, A speed sensor and a torque sensor are provided on the AC motor. A second connector is provided on a metal partition on one side of the AC motor. The output signal lines of the speed sensor and the torque sensor are connected to the signal input terminal of the dynamometer measurement and control unit after passing through the second connector.

3. The integrated AC power dynamometer according to claim 1, characterized in that, A DC power input port is provided on the top of the chassis. The input terminal of the inverter is electrically connected to the DC power input port to provide DC power to the inverter through the DC power input port.

4. The integrated AC power dynamometer according to claim 1, characterized in that, The chassis also includes a pressure sensor, a temperature sensor, and a vibration sensor. The pressure sensor is located on the surface of the AC motor, while the temperature sensor and the vibration sensor are located at the bottom of the chassis near the AC motor. The output signal lines of the pressure sensor, the temperature sensor, and the vibration sensor are all connected to the signal input terminal of the dynamometer measurement and control unit.

Images