Electric mechanical equipment rack testing device and testing method

Abstract

The invention provides an electromechanical equipment rack testing device and testing method. The device comprises an equipment controller, an engine, a generator, a generator controller, an equipment battery, a rack controller, a driving motor simulation assembly and a load battery. The equipment controller is used for sending a control instruction to the engine and generator controller to control an engine and a generator to operate, and the electric quantity of the electric mechanical equipment is stored through the equipment battery; the equipment controller is used for sending a control instruction to the driving motor controller to control the driving motor to rotate; the rack controller is used for sending a control instruction to the load motor controller to simulate load characteristics; and the load battery is used for storing the electric energy output by the tested electric mechanical equipment and providing the electric energy for the load motor and the load motor controller. Based on the device, the invention further provides an electric mechanical equipment rack testing method. According to the invention, energy temporary storage and power grid feedback are combined at the load side, so that the rack load test of the electric mechanical equipment becomes possible.

Description

Technical Field

[0001] The present invention belongs to the technical field of testing of electric mechanical equipment, and particularly relates to a bench testing device and a testing method for electric mechanical equipment. Background Art

[0002] Movable electric mechanical equipment generally uses batteries as the energy source, such as walking robots, aircraft, automobiles, construction machinery, ships, etc. Such equipment can also be supplemented with fuel and internal combustion engines as the energy source. When designing such equipment, it is necessary to first test the main electric components, such as batteries, internal combustion engines, motors, converters, and controllers, etc., in order to understand the built-in performance of the components and the whole machine before mass production of the product and to optimize them. As Figure 1 is a motor test bench of the prior art. Figure 1 The core components of the conventional electric equipment test bench shown include a driving motor and a load motor, which generate opposing torques and can simulate the working conditions of the motor and the drive load. The driving motor and its controller are equivalent to the driving components in the device under test, and the load motor and its controller simulate the external load during the operation of the device. When the driving motor is in the working state, the load motor generates a reverse torque and thus works in the power generation state. The generated electric energy is transmitted back to the driving motor through the DC bus, generating a closed loop of energy flow and avoiding the accumulation of energy on the load side.

[0003] However Figure 1 the disclosed method cannot perform load tests on batteries and engines because the energy output by them has nowhere to be released. To address this problem, Figure 2 discloses a motor test bench equipped with a grid feedback device. Figure 2 The method of working of the disclosed test bench is: using a grid-connected inverter to feed back the electric energy generated by the load motor to the grid, so as to be able to simulate the battery charge and discharge or the engine load operation state. However, in the case of large equipment, the feedback energy is huge and the grid cannot bear it. Therefore Figure 2 the disclosed method has low practical feasibility. For Figure 1 the problems existing, another method adopted is to convert the electric energy generated by the load motor into heat energy through a resistor. This method not only causes a large amount of energy waste, but also has a huge heat dissipation device, high investment and operation costs, and is rarely actually adopted under the current environmental protection and energy conservation requirements. Therefore, the problems existing in the prior art are: the existing electric equipment test bench cannot perform load state tests on engines and batteries. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention proposes a bench testing device and a testing method for electric mechanical equipment, and uses a combination of energy storage and grid feedback technologies on the load side, making it possible to perform bench load tests on electric mechanical equipment.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] An electric mechanical equipment bench test device, comprising: an equipment controller 1, an engine 2, a generator 3, a generator controller 4, an equipment battery 6, a bench controller 21, a drive motor simulation component 10, and a load battery 26;

[0007] The equipment controller 1 is respectively connected to the engine 2, the generator controller 4, and the equipment battery 6, and is used for sending control commands to the engine 2 and the generator controller 4 to control the operation of the engine 2 and the generator 3, and for storing the electric energy of the electric mechanical equipment through the equipment battery 6;

[0008] The equipment controller 1 is connected to a drive motor controller 11 in the drive motor simulation component 10, and is used for sending a control command to the drive motor controller 11 to control the rotation of the drive motor 12;

[0009] The bench controller 21 is connected to a load motor controller 17 in the drive motor simulation component 10, and is used for sending a control command to the load motor controller 17 to simulate the load characteristics;

[0010] The load battery 26 is connected to the load, and is used for storing the electric energy output by the electric mechanical equipment to be tested, and for providing electric energy for the load motor 16 and the load motor controller 17 in the drive motor simulation component 10.

[0011] Further, the number of the drive motor simulation components 10 is one or more.

[0012] Further, the drive motor simulation component 10 includes a drive motor controller 11, a drive motor 12, a flywheel 13, a flywheel counterweight 14, a shaft sensor 15, a load motor 16, and a load motor controller 17 connected in series in sequence;

[0013] The drive motor controller 11 is used for receiving the drive motor control command issued by the equipment controller 1 and controlling the rotation of the drive motor 12;

[0014] The drive motor 12 is mechanically connected to the flywheel rotating shaft and serves as the drive motor in the simulation equipment;

[0015] The flywheel 13 is fixed on the drive motor shaft and rotates synchronously with the drive motor, and is used for simulating the inertia of the equipment itself connected to the drive motor 12;

[0016] The flywheel counterweight 14 is used for simulating the inertia of the load loaded on the equipment;

[0017] The shaft sensor 15 is coaxially connected to the drive motor 12 and is used for measuring the torque on the shaft and the rotational speed of the shaft;

[0018] The load motor 16 is coaxially connected to the drive motor 12 and is used to generate torque to simulate a load;

[0019] The load motor controller 17 is electrically connected to the load motor 16 and is used to output current according to the command of the bench controller 21 to control the rotation of the load motor 16.

[0020] Furthermore, the flywheel inertia of the flywheel 13 is equal to the inertia of the actual equipment drive system connected to the drive motor 12; the inertia of the flywheel counterweight 14 is equal to the inertia of the load loaded on the equipment.

[0021] Furthermore, the device further includes an equipment DC bus capacitor 7 and a load DC bus capacitor 27;

[0022] The equipment DC bus capacitor 7 is connected to the electric mechanical equipment and is used to buffer the current transmission of the components connected to the DC bus of the electric mechanical equipment to prevent the bus voltage from exceeding the limit;

[0023] The load DC bus capacitor 27 is connected to the load and is used to buffer the current transmission of the components connected to the load DC bus to prevent the bus voltage from exceeding the limit.

[0024] Furthermore, the device further includes a measuring instrument 22;

[0025] The measuring instrument 22 is communicatively connected to the bench controller 21 and is used to collect operation data according to the instruction of the bench controller 21.

[0026] Furthermore, the bench controller 21 is also connected to the load battery 26 and is used to control the charge and discharge of the load battery 26.

[0027] Furthermore, the device further includes a grid-connected inverter 24; the DC side of the grid-connected inverter is connected to the load DC bus 25, and the AC side is connected to the power grid, and is used to perform power conversion and transmission between the bench and the power grid according to the instruction of the bench controller.

[0028] The present invention also proposes a method for testing an electric mechanical equipment bench, which is implemented based on an electric mechanical equipment bench testing device and includes the following steps:

[0029] After the bench is powered on, the bench controller starts the grid-connected inverter and the load battery, and starts the test process after determining that the SOC of the load battery enters a preset range;

[0030] After entering the test program, the bench controller starts the measuring instrument to record the required data; and during the test process, the bench controller sends operation instructions to the equipment controller in chronological order, and at the same time controls the operation of the load motor according to the time series of the load motor instructions to simulate the actual load;

[0031] After the bench controller completes the time series of all instructions, it commands the engine to shut down and the measuring instrument to stop recording.

[0032] Furthermore, the method further includes:

[0033] After the bench is powered on and in the standby state, if the SOC of the load battery is lower than the lower limit of the preset range, it is charged from the power grid through the grid-connected inverter; if the SOC of the load battery is higher than the upper limit of the preset range, the grid-connected inverter feeds electrical energy back to the power grid to discharge the load battery.

[0034] During the test process, if the SOC of the load battery is lower than the lower limit of the preset range, the grid-connected inverter is commanded to operate in the rectification mode to charge the load DC bus; if the SOC of the load battery is higher than the upper limit of the preset range, the grid-connected inverter is commanded to operate in the inversion mode to feed electricity to the power grid; if the SOC of the load battery is within the preset range, the grid-connected inverter does not operate.

[0035] The effects provided in the summary of the invention are only the effects of the embodiments, rather than all the effects of the invention. One of the above technical solutions has the following advantages or beneficial effects:

[0036] The present invention proposes a bench test device and a test method for electric mechanical equipment. The device includes an equipment controller, an engine, a generator, a generator controller, an equipment battery, a bench controller, a drive motor simulation component, and a load battery; the equipment controller is respectively connected to the engine, the generator controller, and the equipment battery, and is used to send control instructions to the engine and the generator controller to control the operation of the engine and the generator, and store the electric energy of the electric mechanical equipment through the equipment battery; the equipment controller is connected to the drive motor controller in the drive motor simulation component and is used to send control instructions to the drive motor controller to control the rotation of the drive motor; the bench controller is connected to the load motor controller in the drive motor simulation component and is used to send control instructions to the load motor controller to simulate the load characteristics; the load battery is connected to the load and is used to store the electric energy output by the tested electric mechanical equipment and provide electric energy for the load motor and the load motor controller in the drive motor simulation component. Based on a bench test device for electric mechanical equipment, a bench test method for electric mechanical equipment is also proposed. The present invention uses a combination of energy storage and grid feedback technology on the load side, making it possible to perform bench load tests on electric mechanical equipment, so that electric components can be fully tested at the equipment design stage, thereby detecting problems early, optimizing the design, greatly shortening the design process, and improving the design efficiency.

[0037] When the present invention is implemented, the component to be measured is installed on the test bench in an open manner within a large space, with sufficient space and external conditions to add various sensors and testing instruments. Therefore, more accurate measurements can be carried out, which helps to improve the performance of the equipment. It overcomes the technical problem in the prior art that the load testing of the electric components of such equipment must be installed on the whole machine, and due to the narrow space or other limitations, many sensors cannot be used.

[0038] In the present invention, the load side is fixed, and the equipment side can be flexibly configured according to needs. Therefore, it has good versatility. It helps to greatly reduce the equipment investment cost. Description of the Drawings

[0039] Figure 1 is the motor test bench of the prior art;

[0040] Figure 2 is the motor test bench equipped with a power grid feedback device in the prior art;

[0041] Figure 3 is the schematic diagram of the test bench for a single-motor series hybrid equipment proposed in Embodiment 1 of the present invention;

[0042] Figure 4 is the schematic diagram of the test bench for a double-motor series hybrid equipment proposed in Embodiment 1 of the present invention;

[0043] Figure 5 is the schematic diagram of the test bench for a single-motor parallel hybrid equipment proposed in Embodiment 1 of the present invention;

[0044] Figure 6 is the schematic diagram of the test bench for a double-motor parallel hybrid equipment proposed in Embodiment 1 of the present invention;

[0045] Figure 7 is the schematic diagram of the test bench for a double-motor pure electric equipment proposed in Embodiment 1 of the present invention;

[0046] Figure 8 is the flowchart of a test method for an electric mechanical equipment bench proposed in Embodiment 2 of the present invention;

[0047] Legend: 1 - equipment controller, 2 - engine; 3 - generator; 4 - generator controller; 5 - equipment DC bus; 6 - equipment battery; 7 - equipment DC bus capacitor; 10 - drive motor simulation component; 11 - drive motor controller, 12 - drive motor, 13 - flywheel, 14 - flywheel counterweight, 15 - shaft sensor, 16 - load motor, 17 - load motor controller; 21 - bench controller; 22 - measuring instrument; 24 - grid-connected inverter, 25 - load DC bus, 26 - load battery; 27 - load DC bus capacitor. Detailed Embodiments

[0048] To clearly illustrate the technical features of this solution, the present invention will be elaborated in detail below through specific embodiments and in conjunction with its accompanying drawings. The following disclosure provides many different embodiments or examples for implementing different structures of the present invention. To simplify the disclosure of the present invention, components and settings of specific examples are described below. In addition, the present invention may repeat reference numerals and / or letters in different examples. This repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. It should be noted that the components illustrated in the drawings are not necessarily drawn to scale. The present invention omits the description of well-known components, processing technologies, and processes to avoid unnecessarily limiting the present invention.

[0049] Embodiment 1

[0050] Embodiment 1 of the present invention proposes an electric mechanical equipment bench test device to solve the problem in the prior art that the electric equipment test bench cannot perform load state tests on the engine and battery. An electric mechanical equipment bench test device proposed by the present invention adds a power battery on the load side of the test bench to temporarily store the excess energy generated during the test; a grid-connected inverter is adopted on the load side to feed back electric energy to the grid at a relatively small power that the grid can withstand or consume the energy by local electrical appliances; a flywheel is added to the motor shaft to simulate the inertia of the mechanical equipment itself and the load.

[0051] The flywheel, load battery capacity, and grid-connected inverter in the test bench should be designed or selected according to the test requirements. Specifically, it includes: the flywheel inertia of the flywheel is equal to the inertia of the actual equipment drive system connected to the drive motor, and the flywheel counterweight is equal to the inertia of the load carried by the equipment; the load battery should be able to store all the energy output by the engine and the equipment battery during a single test minus the energy fed back to the grid, and its charge and discharge power should be greater than the maximum power of the drive motor; the maximum inversion power of the grid-connected inverter should be lower than the sum of the total feedback power that the local grid can withstand and the actual power consumption of the electrical appliances in the local grid.

[0052] An electric mechanical equipment bench test device proposed by Embodiment 1 of the present invention includes: equipment controller 1, engine 2, generator 3, generator controller 4, equipment battery 6, bench controller 21, drive motor simulation component 10, and load battery 26;

[0053] The equipment controller 1 is respectively connected to the engine 2, generator controller 4, and equipment battery 6, and is used to send control commands to the engine 3 and generator controller 4 to control the operation of the engine 2 and generator 3, and store the electric energy of the electric mechanical equipment through the equipment battery 6;

[0054] The equipment controller 1 is connected to the drive motor controller 11 in the drive motor simulation component 10 and is used to send control commands to the drive motor controller 11 to control the rotation of the drive motor 12;

[0055] The bench controller 21 is connected to the load motor controller 17 in the drive motor simulation component 10, and is used to send control instructions to the load motor controller 17 to simulate load characteristics;

[0056] The load battery 26 is connected to the load DC bus and is used to store the electric energy output by the tested electric mechanical device and provide electric energy for the load motor 16 and the load motor controller 17 in the drive motor simulation component 10 .

[0057] The generator controller 4, the device battery 6 and the drive motor controller 11 in the drive motor simulation component 10 are connected via the device DC bus 5 to transmit electrical energy;

[0058] The grid-connected inverter 24, the load battery 26 and the load motor controller 17 in the drive motor simulation component 10 are connected via a load DC bus 25 for transmitting electric energy.

[0059] Figure 3 Schematic diagram of a single-motor series hybrid test bench proposed in Example 1 of the present invention; Figure 3 The invention comprises a driving motor simulation component 10;

[0060] The drive motor simulation component 10 includes a drive motor controller 11, a drive motor 12, a flywheel 13, a flywheel counterweight 14, an axis sensor 15, a load motor 16 and a load motor controller 17 which are connected in series in sequence;

[0061] The drive motor controller 11 is used to receive the drive motor control instruction sent by the device controller 1 and control the drive motor 12 to rotate;

[0062] The drive motor 12 is mechanically connected to the flywheel shaft and serves as the drive motor in the simulation device;

[0063] The flywheel 13 is fixed on the drive motor shaft and rotates synchronously with the drive motor to simulate the inertia of the transmission system of the device connected to the drive motor 12; the flywheel counterweight 14 is used to simulate the inertia of the load carried by the device and add extra inertia to the flywheel. When unloaded, it is detached from the flywheel and can be removed from the stand. When simulating the load state, it is fixed to the flywheel through a connector and is integrated with the flywheel. It rotates synchronously with the drive motor to simulate the inertia of the device connected to the drive motor under load. The flywheel inertia of the flywheel 13 is equal to the actual inertia of the device connected to the drive motor 12; the flywheel counterweight 14 is equal to the inertia of the loaded load;

[0064] The shaft sensor 15 is coaxially connected to the drive motor 12 and is used to measure the torque on the shaft and the speed of the shaft;

[0065] The load motor 16 is coaxially connected to the drive motor 12 and is used to generate torque and simulate load;

[0066] The load motor controller 17 is electrically connected to the load motor 16 and is used to output current according to the command of the test bench controller 21 to control the rotation of the load motor 16.

[0067] In Figure 3 it, the engine 2, generally an internal combustion engine, uses diesel or gasoline as fuel.

[0068] A generator 3 is arranged between the engine 2 and the generator controller 4. The generator 3 is mechanically connected to the engine 2 coaxially and converts the mechanical energy output by the engine 2 into electrical energy.

[0069] The generator controller 4 is electrically connected to the generator 3 and the equipment DC bus 5 and controls the operation of the generator according to the instructions of the equipment controller.

[0070] The equipment DC bus 5 connects the DC terminals of all the power components of the equipment to transmit electrical energy.

[0071] The test bench controller 21 is the main controller of the test bench. Its functions include: 1. Sending instructions to the equipment controller to make the equipment components simulate actual working conditions. 2. Sending instructions to the measuring instrument to command it to collect data as required. 3. Sending commands to the load motor controller to simulate load characteristics. 4. Sending commands to the grid-connected inverter to make it perform energy conversion as required. 5. Sending commands to the load battery to make it charge and discharge as required. 6. Monitoring the operation of the test bench and handling abnormal situations.

[0072] The load DC bus 25 connects the DC terminals of all the power components on the load side to transmit electrical energy.

[0073] The device further includes a measuring instrument 22; the measuring instrument 22 is communicatively connected to the test bench controller 21 and is used to collect operation data according to the instructions of the test bench controller 21.

[0074] The device further includes a grid-connected inverter; the DC side of the grid-connected inverter is connected to the load DC bus, and the AC side is connected to the power grid, and is used to perform power conversion and transmission between the test bench and the power grid according to the instructions of the test bench controller.

[0075] The device includes an equipment DC bus capacitor 7 and a load DC bus capacitor 27;

[0076] The equipment DC bus capacitor 7 is connected to the DC bus of the electromechanical equipment and is used to buffer the current transmission of the components connected to the DC bus of the electromechanical equipment to prevent the bus voltage from exceeding the limit;

[0077] The load DC bus capacitor 27 is connected to the load DC bus and is used to buffer the current transmission of the components connected to the load DC bus to prevent the bus voltage from exceeding the limit.

[0078] The present invention can test a variety of different device architectures. If the device has multiple drive mechanisms, any number of motor back-to-back systems can be added between the device DC bus and the load DC bus.

[0079] Figure 4 It is a schematic diagram of a dual-motor series hybrid test bench proposed in Embodiment 1 of the present invention; Figure 4 On the basis of Figure 3 , 2 drive motor simulation components 10 are set. The protection scope of the present invention is not limited to the 2 drive motor simulation components listed. Those skilled in the art can make reasonable settings according to the actual situation. Figure 4 The present method is also applicable to parallel hybrid electric devices.

[0080] It is a schematic diagram of a single-motor parallel hybrid device test bench proposed in Embodiment 1 of the present invention. Figure 5 On the basis of the single-drive motor parallel hybrid architecture, a set of back-to-back motors can be added.

[0081] It is a schematic diagram of a dual-motor parallel hybrid device test bench proposed in Embodiment 1 of the present invention. Figure 6

[0082] If the engine is removed and only the device battery is used as the energy source, the present method can also be used for pure electric mechanical equipment. Figure 7 It is a schematic diagram of a dual-motor pure electric device test bench proposed in Embodiment 1 of the present invention.

[0083] During the standby and test processes of the test bench of the present application, in order to enable the load motor to operate normally, the load battery should store a certain amount of electricity. During the test process, the device generally outputs energy to the load, and most of this energy will be stored in the load battery, resulting in an increase in the battery SOC (the percentage of the electricity stored in the battery in the total capacity). In some tests, it may be that the device side absorbs energy from the load side, which will cause the load battery SOC to decrease. In order to ensure the successful progress of the test, the user should specify the load battery SOC range in advance. Only when it enters this range can the test be successfully completed. For this reason, the test bench controller should control the grid-connected inverter and the load battery according to the following method.

[0084] After the test bench is powered on and in the standby state, if the load battery SOC is lower than the lower limit of the specified range, it is charged from the grid through the grid-connected inverter. If its SOC is higher than the upper limit of the specified range, electrical energy is fed back to the grid through the grid-connected inverter to make the load battery discharge. When the SOC enters the specified range, the test bench controller allows the test program to be started.

[0085] ​During the test process, continue to control the current flow direction of the grid-connected inverter according to a similar strategy, that is, if the SOC of the load battery is lower than the lower limit of the specified range, command the grid-connected inverter to operate in the rectification mode to charge the load DC bus. If the SOC of the load battery is higher than the upper limit of the specified range, command the grid-connected inverter to operate in the inversion mode to feed power to the grid. If the SOC of the load battery is within the specified range, the grid-connected inverter does not operate.

[0086] During the test process, energy flows frequently between the device side and the load side DC buses. The load battery automatically charges and discharges according to the change of the load DC bus voltage.

[0087] Due to the above functions, the test bench can simulate all operating conditions of the device, including standby (the engine idles and the generator outputs zero power), no-load operation (the load motor outputs zero torque), and load operation (the load motor outputs non-zero torque). The engine can operate at any load rate, and the device battery can charge and discharge at any current. In addition, due to the use of a flywheel, the test bench can fully simulate the actual conditions during the acceleration and deceleration processes of the device, thus completely testing the electrical characteristics of the device's power system.

[0088] The present invention can also connect a power resistor in parallel on the load DC bus, and its switch is controlled by the test bench controller, which can accelerate the discharge of the load battery.

[0089] A test device for an electric mechanical equipment test bench proposed in Embodiment 1 of the present invention uses a technology that combines energy storage and grid feedback on the load side, making it possible to perform a load test on the test bench of the electric mechanical equipment. Thus, the electric components can be fully tested at the device design stage, so as to detect problems early, optimize the design, greatly shorten the design process, and improve the design efficiency.

[0090] A test device for an electric mechanical equipment test bench proposed in Embodiment 1 of the present invention, when executed, the component under test is installed on the test bench in an open manner in a large space, and there is enough space and external conditions to add various sensors and test instruments. Therefore, more accurate measurements can be carried out, which helps to improve the device performance. It overcomes the technical problem in the prior art that the load test of the electric components of such devices must be installed on the whole device for testing. Due to the narrow space or other restrictions, many sensors cannot be used.

[0091] A test device for an electric mechanical equipment test bench proposed in Embodiment 1 of the present invention has a fixed load side and a device side that can be flexibly configured according to needs, so it has good versatility. It helps to greatly reduce the equipment investment cost.

[0092] Embodiment 2

[0093] Based on the electric mechanical equipment bench test device proposed in Embodiment 1 of the present invention, Embodiment 2 of the present invention also proposes an electric mechanical equipment bench test method, and this method is the working process of the electric mechanical equipment bench test device proposed in Embodiment 1 of the present invention. Regarding the composition of the electric mechanical equipment bench test device, it has been described in detail in Embodiment 1 and will not be elaborated in Embodiment 2.

[0094] Figure 8 It is a flowchart of an electric mechanical equipment bench test method proposed in Embodiment 2 of the present invention.

[0095] In step S1, after the bench is powered on, the bench controller starts the grid-connected inverter and the load battery, and starts the test process after determining that the SOC of the load battery enters the preset range;

[0096] After the bench is powered on and in the standby state, if the SOC of the load battery is lower than the lower limit of the preset range, it is charged from the grid through the grid-connected inverter; if the SOC of the load battery is higher than the upper limit of the preset range, the grid-connected inverter feeds electrical energy back to the grid to discharge the load battery.

[0097] In step S2, after entering the test program, the bench controller starts the measuring instrument to record the required data; and during the test process, the bench controller sends operation instructions to the equipment controller in chronological order, and at the same time controls the operation of the load motor according to the time series of the load motor instructions to simulate the actual load;

[0098] During the test process, if the SOC of the load battery is lower than the lower limit of the preset range, the grid-connected inverter is commanded to work in the rectification mode to charge the load DC bus; if the SOC of the load battery is higher than the upper limit of the preset range, the grid-connected inverter is commanded to work in the inversion mode to feed power to the grid; if the SOC of the load battery is within the preset range, the grid-connected inverter does not work.

[0099] In step S3, after the bench controller completes the time series of all instructions, it commands the engine to stop and the measuring instrument to stop recording.

[0100] In step S4, after the test is completed, the user reads the data through the bench controller for analysis and processing.

[0101] To fully illustrate the implementation process of the electric mechanical equipment bench test method proposed in Embodiment 2 of the present invention, a case of testing the power system of an electric forklift is taken as an example for illustration.

[0102] The forklift adopts a series hybrid energy source combined with a diesel engine and a battery. The self-weight of the equipment is 3500 kg, the maximum load is 4500 kg, the load walking speed is 13 km / h, the corresponding walking motor speed is 750 rpm, the self-weight of the fork and movable attachments is 200 kg, the maximum lifting speed of the fork is 0.4 m / s, and the corresponding fork motor speed is 750 rpm. The rated power of both motors is 75 kW.

[0103] To simulate the working conditions of the walking motor and the fork motor, the bench structure adopts Figure 4 the dual-motor series hybrid test bench scheme in

[0104] Given the corresponding relationship between the walking speed and the motor speed, the equivalent moment of inertia on the motor shaft can be calculated according to the law of conservation of energy. Define the moment of inertia of the flywheel as J and the speed as ω, then the kinetic energy of the flywheel when the motor rotates is:

[0105]

[0106] Define the mass of the forklift as m and the speed as v, then the kinetic energy when the forklift is walking is:

[0107]

[0108] From W m = W d , we get

[0109]

[0110] From the above formula, the equivalent moment of inertia of the walking motor shaft when unloaded is

[0111]

[0112] The equivalent moment of inertia of the walking motor shaft when rated loaded is

[0113]

[0114] Therefore, the flywheel inertia on the drive motor shaft corresponding to the equipment walking motor on the bench should be 7.40 kg·m², and the counterweight inertia is 16.91 - 7.40 = 9.51 kg·m².

[0115] If a solid steel cylinder with a radius of r = 0.2 m is used to make the flywheel, the following formula can be used to calculate the length L of the cylinder (ρ is the density of steel):

[0116]

[0117] When no load, L = 0.075m, and when at rated load, L = 0.171m. That is, the flywheel on the walking motor shaft is a steel cylinder with a diameter of 400mm and a length of 75mm; the flywheel counterweight is a cylinder with the same diameter and a length of 96mm.

[0118] Using this method, the flywheel inertia on the fork motor shaft can also be obtained as follows: 0.0052 kg·m² when no load, and 0.13 kg·m² when at rated load. If a steel cylinder is used to make the flywheel, the required flywheel diameter at rated load is 100mm and the length is 87.5mm. This is equivalent to the size of the connecting component between the drive and load motors. That is, there is no need to use a flywheel.

[0119] Then calculate the main parameters of the load battery. Here, it is assumed that the grid-connected inverter is not allowed to perform energy feedback during the test, that is, all the extra energy generated by the test bench needs to be stored in the load battery.

[0120] The maximum output power of the forklift should be the sum of the maximum powers of the two motors, that is, 150kW. If the DC bus voltage on the load side is 550V, then the maximum charging current of the load battery is 15000 / 550 = 273A.

[0121] The capacity of the load battery should be greater than the total energy output of the forklift during the load test. Since the walking motor is mainly used for acceleration and deceleration, the load battery is charged during acceleration and discharged during deceleration. The difference between charging and discharging is roughly the friction loss power. When walking at a constant speed, the motor power only needs to overcome the friction loss. Therefore, when the equipment is walking, the average output power of the walking motor is equal to the friction loss power, which can be calculated according to 10% of the rated power. The energy consumption of the fork motor is the largest when lifting. Assume that the test task is to simply move a batch of materials from a low place to a high place. When the fork is lifted, the motor outputs the rated power, and when it descends, it is in the no-load state and basically does not consume energy. There may even be a small amount of feedback energy generated by the gravity of the fork, resulting in a slight decrease in the SOC of the load battery. Therefore, the impact of descent can be ignored. Assume that the lifting process occupies 50% of the test time, then the average output power of the fork motor is 50% of the rated power. Assume that a handling operation can be completed in 30 seconds, and each test is repeated 10 times, then the total time is 30 minutes. Therefore, the total energy output of the two drive motors during the entire load test process can be calculated as follows:

[0122] W L =(P1 + P2)t=(0.1×75kW + 0.5×75kW)×0.5h = 22.5kWh.

[0123] If a 20% margin is left, the capacity of the load battery should be greater than 28.2kWh. The current market price of such a battery is about 15,000 yuan RMB, and the cost is only one-fortieth of the entire test bench. If the grid can receive part of the feedback during the test, the capacity of the battery can be reduced.

[0124] After the test is completed, if the load battery is close to full charge. Before the next similar test, the battery must be discharged. At this time, power can be fed back to the grid, or electrical appliances can be connected on the grid side, or a power resistor can be connected to the load DC bus for rapid discharge.

[0125] A test method for an electric mechanical equipment bench proposed in Embodiment 2 of the present invention uses a combination of energy storage and grid feedback technologies on the load side, making it possible to conduct bench load tests on electric mechanical equipment. Thus, electric components can be fully tested at the equipment design stage, problems can be detected early, the design can be optimized, the design process can be greatly shortened, and the design efficiency can be improved.

[0126] For the description of an electric mechanical equipment bench test device in the electric mechanical equipment bench test method provided in Embodiment 2 of this application, reference can be made to the detailed description of the corresponding part in the electric mechanical equipment bench test device provided in Embodiment 1 of this application, and details will not be repeated here.

[0127] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "including", "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes the inherent elements thereof. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of additional identical elements in the process, method, article or device including the said element. In addition, the parts of the above technical solutions provided in the embodiments of this application that are consistent with the corresponding technical solutions in the prior art in terms of implementation principles are not described in detail to avoid excessive elaboration.

[0128] Although the specific implementation manners of the present invention are described above in conjunction with the accompanying drawings, it is not a limitation to the protection scope of the present invention. For those skilled in the art, other different forms of modification or variation can be made on the basis of the above description. It is not necessary and impossible to list all the implementation manners here. Based on the technical solutions of the present invention, various modifications or variations that can be made by those skilled in the art without creative efforts are still within the protection scope of the present invention.

Claims

1. An electric mechanical equipment bench test device, characterized in that: include: A device controller (1), an engine (2), a generator (3), a generator controller (4), a device battery (6), a bench controller (21), a drive motor simulation component (10), and a load battery (26); The device controller (1) is connected to the engine (2), the generator controller (4) and the device battery (6) respectively, and is used to send control instructions to the engine (2) and the generator controller (4), control the operation of the engine (2) and the generator (3), and store the electricity of the electric mechanical device through the device battery (6); The device controller (1) is connected to a drive motor controller (11) in a drive motor simulation component (10) and is used to send a control instruction to the drive motor controller (11) to control the rotation of the drive motor (12); The bench controller (21) is connected to the load motor controller (17) in the drive motor simulation component (10) and is used to send control instructions to the load motor controller (17) to simulate load characteristics; The load battery (26) is connected to the load and is used to store the electric energy output by the electric mechanical device under test and to provide electric energy for the load motor (16) and the load motor controller (17) in the drive motor simulation component (10).

2. The electric mechanical equipment bench test device according to claim 1, characterized in that: The number of the driving motor simulation components (10) is one or more.

3. The electric mechanical equipment bench test device according to claim 1, characterized in that: The drive motor simulation component (10) comprises a drive motor controller (11), a drive motor (12), a flywheel (13), a flywheel counterweight (14), an axis sensor (15), a load motor (16) and a load motor controller (17) which are sequentially connected in series; The drive motor controller (11) is used to receive a drive motor control instruction issued by the device controller (1) and control the rotation of the drive motor (12); The drive motor (12) is mechanically connected to the flywheel shaft and serves as the drive motor in the simulation device; The flywheel (13) is fixed on the drive motor shaft and rotates synchronously with the drive motor, and is used to simulate the inertia of the device connected to the drive motor (12); The flywheel counterweight (14) is used to simulate the inertia of the load carried by the device; The shaft sensor (15) is coaxially connected to the drive motor (12) and is used to measure the torque on the shaft and the rotation speed of the shaft; The load motor (16) is coaxially connected to the drive motor (12) and is used to generate torque and simulate load; The load motor controller (17) is electrically connected to the load motor (16) and is used to output current according to a command from the gantry controller (21) to control the rotation of the load motor (16).

4. The electric mechanical equipment bench test device according to claim 3, characterized in that: The flywheel inertia of the flywheel (13) is equal to the inertia of the actual equipment transmission system connected to the drive motor (12); the inertia of the flywheel counterweight (14) is equal to the inertia of the load carried by the equipment.

5. The electric mechanical equipment bench test device according to claim 1, characterized in that: The device also includes a device DC bus capacitor (7) and a load DC bus capacitor (27); The device DC bus capacitor (7) is connected to the electric mechanical device and is used to buffer the current transmission of components connected to the DC bus of the electric mechanical device to prevent the bus voltage from exceeding the limit; The load DC bus capacitor (27) is connected to the load and is used to buffer the current transmission of components connected to the load DC bus to prevent the bus voltage from exceeding the limit.

6. The electric mechanical equipment bench test device according to claim 1, characterized in that: The device also includes a measuring instrument (22); The measuring instrument (22) is connected to the bench controller (21) in communication, and is used to collect operation data according to the instructions of the bench controller (21).

7. The electric mechanical equipment bench test device according to claim 1, characterized in that: The platform controller (21) is also connected to the load battery (26) and is used to control the charging and discharging of the load battery (26).

8. The electric mechanical equipment bench test device according to claim 1, characterized in that: The device also includes a grid-connected inverter (24); the DC side of the grid-connected inverter is connected to the load DC bus (25), and the AC side is connected to the power grid, and is used to convert and transmit electric energy between the test bench and the power grid according to the instructions of the test bench controller.

9. A bench test method for electric mechanical equipment, implemented based on the bench test device for electric mechanical equipment according to any one of claims 1 to 8, characterized in that: The following steps are involved: After the test bench is powered on, the test bench controller starts the grid-connected inverter and the load battery, and starts the test process after judging that the load battery SOC enters the preset range; After entering the test program, the bench controller starts the measuring instrument and records the required data; and during the test, the bench controller sends the operation instructions to the equipment controller in time sequence, and controls the load motor to run according to the time sequence of the load motor instructions to simulate the actual load; After the test bench controller completes the time sequence of all instructions, it commands the engine to stop and the measuring instrument to stop recording.

10. The bench test method for electric mechanical equipment according to claim 9, characterized in that: The method further comprises: After the test bench is powered on, in standby mode, if the load battery SOC is lower than the lower limit of the preset range, it will be charged from the grid through the grid-connected inverter; if the load battery SOC is higher than the upper limit of the preset range, it will feed back power to the grid through the grid-connected inverter to discharge the load battery; During the test, if the load battery SOC is lower than the lower limit of the preset range, the grid-connected inverter is commanded to operate in rectification mode to charge the load DC bus. If the load battery SOC is higher than the upper limit of the preset range, the grid-connected inverter is commanded to operate in inverter mode to feed power to the grid. If the load battery SOC is within the preset range, the grid-connected inverter does not operate.

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