A comprehensive test system and method for oil-free compressor performance

Abstract

The present invention discloses a comprehensive performance test system for oil-free compressors. The system includes a test assembly connected to two compressors on a duplex station. The test assembly includes an electrical test subassembly and an air circuit test subassembly. The electrical test subassembly includes a withstand voltage test unit and an inter-turn test unit. The withstand voltage test unit is used to dynamically test the electrical insulation and withstand voltage between the rotor and the stator inside the compressor. The inter-turn test unit is used to test the insulation performance of the coil winding of the rotor inside the compressor. The test items of the test system cover the performance tests of withstand voltage performance, inter-turn withstand voltage performance, start-up performance with pressure, stall performance, and hard indicators such as current, power, flow, and noise during normal load operation. At the moment when the withstand voltage, inter-turn, under pressure, stall, and simulated load tests are completed, the test system automatically switches to other test operations, which can effectively improve the test efficiency and data traceability, reduce the work intensity, and save human resources.

Description

Technical Field

[0001] The present invention relates to the technical field of testing of oil-free compressors, and in particular to an integrated double-station test system and method for comprehensive performance testing of oil-free compressors capable of performing withstand voltage testing, turn-to-turn testing, pressure testing, performance testing and stall testing. Background Art

[0002] The compressor consists of two main components: the host and the drive motor. The host is the core component of the compressor and directly affects the performance of the compressor. According to the working principle of the compressor, the host structure includes the intake valve, the movement (mainly the stator and rotor components), the minimum pressure valve, the unloading valve, the temperature control valve, the cooling system, etc. Its main performance indicators include flow, current, temperature, pressure, and unloading time. Due to the structure of the internal circuit of the compressor, the withstand voltage test, turn-to-turn test, and performance test are different test methods. The traditional withstand voltage test, turn-to-turn test, and performance test methods and manual data recording cannot efficiently and reliably collect accurate withstand voltage, electrical insulation, and performance parameters, resulting in a long quality inspection cycle and cumbersome data tracing, which not only has low measurement efficiency but also high cost. Summary of the invention

[0003] In order to solve the defects of the above-mentioned technology, the present invention provides an oil-free compressor performance comprehensive testing system and testing method which can perform withstand voltage test, turn-to-turn test, pressure test, performance test and stall test in an integrated double-station test.

[0004] The technical solution adopted by the present invention to achieve the above technical effects is:

[0005] An oil-free compressor performance comprehensive test system includes a double station for accommodating two compressors to be tested, the two compressors to be tested on the double station are connected to the same set of test assemblies, and the test assembly includes an electrical test subassembly and a gas circuit test subassembly;

[0006] The electrical test subassembly includes a withstand voltage test unit and an inter-turn test unit. The withstand voltage test unit is used to dynamically test the electrical insulation and withstand voltage between the rotor and the stator inside the compressor. The inter-turn test unit is used to test the insulation performance of the coil winding of the rotor inside the compressor.

[0007] The gas circuit test subassembly includes a gas tank, a drainage solenoid valve is provided at the drainage port of the gas tank, and the exhaust pipeline of the gas tank is sequentially connected with an air pressure detection unit, an electrical proportional valve, a flow detection unit, an exhaust solenoid valve and a float flowmeter in the direction from upstream to downstream, and the withstand voltage test unit, the turn-to-turn test unit, the drainage solenoid valve, the air pressure detection unit, the electrical proportional valve, the flow detection unit, the exhaust solenoid valve and the float flowmeter are all connected with a PLC unit and a switch power supply, and the PLC unit is connected with a display module and a data archiving module;

[0008] The compressor is connected to a variable frequency power supply, and the variable frequency power supply is communicatively connected with the PLC unit to provide a normal operating voltage or a withstand voltage test voltage for the compressor.

[0009] Preferably, the above-mentioned oil-free compressor performance comprehensive test system also includes a four-channel analog input module, which is connected to the voltage output end of the switching power supply, and the analog signal output ends of the air pressure detection unit and the flow detection unit are respectively connected to the analog voltage input ends of the third channel and the fourth channel of the four-channel analog input module, and the four-channel analog input module is communicatively connected to the PLC unit.

[0010] Preferably, the above-mentioned oil-free compressor performance comprehensive test system also includes a two-channel analog output module, the air pressure regulation signal output port of the electric proportional valve is connected to the current input port of the first channel of the two-channel analog output module, and the two-channel analog output module is communicatively connected to the PLC unit.

[0011] Preferably, the above-mentioned oil-free compressor performance comprehensive test system also includes a barcode scanning gun connected to the serial port communication of the PLC unit.

[0012] The present invention also discloses a comprehensive test method for oil-free compressor performance. The test method is based on the above-mentioned comprehensive test system for oil-free compressor performance. The test method comprises the following steps:

[0013] S1. Power on the system, start the running configuration, call the corresponding product formula, log in the user, scan the product code and start the test;

[0014] S2, perform withstand voltage test, turn-to-turn test, pressure test, performance test and stall test. After the previous test is completed, the corresponding test relay of the next test is connected, and the test relay of the previous test is reset, and the next test is automatically switched. Abnormal test results will be reported and data archived.

[0015] Preferably, in the above-mentioned comprehensive test method for the performance of oil-free compressors, when performing the withstand voltage test, if the withstand voltage test switch condition is on, the normal withstand voltage test process is entered; if the condition is off, the withstand voltage test contactor is triggered to close, and the next step is entered; the normal withstand voltage test process is: turn on the withstand voltage test AC contactor; if the withstand voltage test times out or does not meet the design requirements, the test is ended, an error message is prompted, and data is archived; if the design requirements are met, the withstand voltage test contactor is triggered to close, and the next step is entered.

[0016] Preferably, in the above-mentioned comprehensive test method for the performance of an oil-free compressor, when performing the inter-turn test, if the inter-turn test switch condition is on, the normal process of inter-turn detection is entered; if the condition is off, the inter-turn test contactor is triggered to be closed, and the next step is entered; the normal process of inter-turn detection is: the inter-turn detection AC contactor is turned on; if the inter-turn detection times out or does not meet the design requirements, the test is terminated, an error message is prompted, and data is archived; if the design requirements are met, the inter-turn test contactor is triggered to be closed, and the next step is entered.

[0017] Preferably, in the above-mentioned comprehensive test method for the performance of oil-free compressors, when performing the pressure test, if the pressure test switch condition is on, the normal process of pressure start detection is entered; if the condition is off, the next step is entered; the normal process of pressure start detection is: connect the test power AC contactor, determine whether the air pressure reaches the pressure start design requirements, if it meets the design requirements, disconnect the test power AC contactor, delay for 2 seconds, then connect the test power AC contactor and perform another pressure start test; if the air pressure does not meet the design requirements, the test is terminated, an error message is prompted and data is archived; if it meets the design requirements, the next step is entered.

[0018] Preferably, in the above-mentioned comprehensive performance test method for oil-free compressors, when performing the performance test, the compressor is started and operated normally to the air pressure standard + 10kPa, the exhaust solenoid valve is opened, and the hard indicators such as current, power, flow, and noise are recorded after the exhaust reaches a steady state. If the parameters in the record do not meet the design requirements, unqualified information is prompted. If the entire process test is completed normally, the compressor and the exhaust solenoid valve are closed and the data is archived;

[0019] When performing the stall test, the test power supply AC contactor is turned on after setting the simulated stall voltage. If the current exceeds the limit or does not meet the design requirements, the test is terminated, an error message is prompted, and data is archived. If the design requirements are met, the next step is entered.

[0020] The beneficial effects of the present invention are as follows: the test items of the test system and the test method of the present invention cover the performance tests of withstand voltage performance, turn-to-turn withstand voltage performance, start-up performance with pressure, stall performance, and performance tests of hard indicators such as current, power, flow, and noise during normal load operation. The parameters recorded in the running test can be automatically saved and archived, and the test forms are automatically converted to other test runs at the moment when the withstand voltage, turn-to-turn, start-up performance with pressure, stall, and simulated load tests are completed. The reliable product data traceability enables the present invention to effectively improve the test efficiency and data traceability when applied to field tests, reduce the workload, and save human resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a system hardware structure block diagram of the test system of the present invention;

[0022] Figure 2 A wiring diagram for the test assembly of the test system of the present invention;

[0023] Figure 3 A schematic diagram of an electrical test subassembly of a test system of the present invention;

[0024] Figure 4 It is a schematic diagram of the gas circuit test subassembly of the test system of the present invention;

[0025] Figure 5 A brief flow chart of the test method of the present invention;

[0026] Figure 6 It is a test start-up and withstand voltage test flow chart of the test method of the present invention;

[0027] Figure 7 It is a turn-to-turn test flow chart of the test method of the present invention;

[0028] Figure 8 The pressure test flow chart of the test method of the present invention (above);

[0029] Fig. 9 The pressure test flow chart of the test method of the present invention (below);

[0030] Fig.10 is a performance test flow chart of the test method of the present invention (above);

[0031] Fig.11 The performance test flow chart of the test method of the present invention (below)

[0032] Fig.12 This is a flow chart of the stall test of the test method of the present invention. DETAILED DESCRIPTION

[0033] In order to further understand the present invention, the present invention is further described below with reference to the accompanying drawings and specific embodiments:

[0034] In the description of the present invention, it should be noted that the terms "vertical", "upper", "lower", "horizontal", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, "first", "second", "third", and "fourth" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0035] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection, it can be a mechanical connection, it can be an electrical connection, it can be a direct connection, it can be connected through an intermediate medium, and it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] like Figure 1 As shown, an embodiment of the present invention provides an oil-free compressor performance comprehensive test system, which includes a double station for placing two compressors to be tested, the double station is a left station and a right station, and compressors 1 and 2 are placed accordingly. The compressors 1 and 2 on the left station and the right station are connected to the same set of test assemblies, which include an electrical test subassembly and a gas circuit test subassembly.

[0037] Specifically, Figure 3 As shown, the electrical test subassembly includes a withstand voltage test unit and an inter-turn test unit. The withstand voltage test unit is used to dynamically test the electrical insulation and withstand voltage between the rotor and the stator inside the compressor, and the inter-turn test unit is used to test the insulation performance of the coil winding of the rotor inside the compressor.

[0038] Specifically, Figure 4As shown, the gas circuit test subassembly includes a gas tank, and the gas tank's drain port is provided with a drain solenoid valve. The gas tank's exhaust pipeline is connected with an air pressure detection unit, an electrical proportional valve, a flow detection unit, an exhaust solenoid valve and a float flowmeter in sequence from upstream to downstream. A float flowmeter is added at the end of the gas circuit. The flow detection unit can be compared before daily testing, and then the ratio of the flow detection unit to the float flowmeter is taken for compensation to reduce the impact of the air temperature and humidity on the flow detection unit on that day. The withstand voltage test unit, the turn-to-turn test unit, the drain solenoid valve, the air pressure detection unit, the electrical proportional valve, the flow detection unit, the exhaust solenoid valve and the float flowmeter are all connected with a PLC unit and a switching power supply, and the PLC unit is connected with a display module and a data archiving module.

[0039] Furthermore, in a preferred embodiment of the test system of the present invention, compressor 1 and compressor 2 are connected to a variable frequency power supply, which is in communication connection with the PLC unit to provide normal operating voltage or withstand voltage test voltage for compressor 1 and compressor 2. Figure 2 As shown, it is the assembly circuit diagram of the test assembly of the present invention, the withstand voltage test unit and the turn-to-turn test unit are connected to the power supply and the PLC unit through the corresponding on-off control circuits, the exhaust solenoid valve and the drain solenoid valve are connected to the switch power supply and the PLC unit through the corresponding on-off control circuits, and the compressor 1 and the compressor 2 are connected to the switch power supply, the variable frequency power supply and the PLC unit through the corresponding on-off control circuits. Each on-off control circuit is composed of a relay and a contactor, wherein the current input end of the relay in the on-off control circuit corresponding to the withstand voltage test unit and the turn-to-turn test unit is connected to the signal trigger enable end of the PLC unit and the power supply, one end of the contactor is connected to the current output end of the relay, and the other end is connected to the withstand voltage test unit, the turn-to-turn test unit and the other pole of the power supply, and the power supply provides a 24V DC working voltage for the on-off control circuit and the withstand voltage test unit and the turn-to-turn test unit. The current input end of the relay in the on-off control circuit corresponding to the exhaust solenoid valve and the drain solenoid valve is connected to the signal trigger enable end and the switch power supply of the PLC unit, one end of the contactor is connected to the current output end of the relay, and the other end is connected to the exhaust solenoid valve, the drain solenoid valve and the other pole of the switch power supply, and the switch power supply provides the exhaust solenoid valve and the drain solenoid valve with a switch working voltage. The current input end of the relay in the on-off control circuit corresponding to compressor 1 and compressor 2 is connected to the signal trigger enable end and the switch power supply of the PLC unit, one end of the contactor is connected to the current output end of the relay, and the other end is connected to compressor 1 and compressor 2 and the other pole of the variable frequency power supply, and the variable frequency power supply provides the normal operation voltage or withstand voltage test voltage for compressor 1 and compressor 2.

[0040] Furthermore, in a preferred embodiment of the test system of the present invention, a four-channel analog input module and a two-channel analog output module are also included. The four-channel analog input module is connected to the voltage output end of the switching power supply, and the analog signal output ends of the air pressure detection unit and the flow detection unit are respectively connected to the analog voltage input ends of the third channel and the fourth channel of the four-channel analog input module, and the four-channel analog input module is connected to the PLC unit for communication. The four-channel analog input module is used to convert the corresponding analog signals of the air pressure and flow detected by the air pressure detection unit and the flow detection unit into digital signals, and then transmit them to the PLC unit, and the corresponding control commands are output by the PLC unit to complete the control of the exhaust solenoid valve and the drainage solenoid valve, and perform exhaust, drainage and other actions. The air pressure adjustment signal output port of the electric proportional valve is connected to the current input port of the first channel of the two-channel analog output module, and the two-channel analog output module is connected to the PLC unit for communication. The two-channel analog output module is used to convert the digital signal output by the PLC unit into an analog signal, and send it to the electric proportional valve, and control the exhaust volume of the exhaust solenoid valve through the electric proportional valve. In a preferred embodiment of the present invention, the four-channel analog input module selects Mitsubishi's analog input module model FX3U-4AD, the two-channel analog output module selects Mitsubishi's analog output module model FX2N-2DA, the PLC unit selects Mitsubishi's PLC model FX3U-32MR, the air pressure detection unit selects SMC ISE30A air pressure detection gauge, and the electric proportional valve selects SMC electric proportional valve.

[0041] Furthermore, in a preferred embodiment of the test system of the present invention, it also includes a barcode scanner connected to the serial port communication of the PLC unit. The optional barcode scanner can scan the product barcode and automatically call the test parameters corresponding to the product model being tested. The test data corresponds to the product barcode one by one, which can realize faster testing operations and achieve automated testing.

[0042] On the other hand, Figure 5 As shown, an embodiment of the present invention further proposes a comprehensive test method for oil-free compressor performance. The test method is based on the above-mentioned comprehensive test system for oil-free compressor performance. The test method includes the following steps:

[0043] S1. Power on the system, start the running configuration, call the corresponding product formula, log in the user, and start the test after scanning the product code. The above three conditions must be met before the test can be carried out, otherwise an error message will be prompted. If the conditions are met, proceed to the next step. After starting the running configuration system and logging in the current user, determine whether the current of each test is normal. If the current exceeds the limit, the test will end, an error message will be prompted, and data will be archived. If the design requirements are met, proceed to the next step.

[0044] S2, perform withstand voltage test, turn-to-turn test, pressure test, performance test and stall test. After the previous test is completed, the corresponding test relay of the next test is connected, and the test relay of the previous test is reset, and the next test is automatically switched. Abnormal test results will be reported and data archived.

[0045] Add a float flowmeter at the end of the gas circuit, compare the mass flowmeter before testing every day, and then take the ratio of the flow detection unit to the float flowmeter for compensation to reduce the impact of the air temperature and humidity on the mass flowmeter. Test the left and right double stations in turn to reduce the beat delay caused by the compressor installation circuit and gas circuit, and improve the test efficiency. During the test, the indicator light of the current station is always on. When the test result is NG, the indicator light flashes at a frequency of 50% duty cycle with a period of 1 second.

[0046] Specifically, Figure 6 As shown, in a preferred embodiment of the test method of the present invention, before the withstand voltage test, the system is powered on, the configuration is run, the recipe is selected, the user is logged in, the product barcode information is scanned by the barcode scanner and uploaded to the system, and then the left start button and the right start button are started in turn to perform the entire test item in turn. When the withstand voltage test is performed, if the withstand voltage test switch condition is on, the withstand voltage test normal process is entered, and if the condition is off, the withstand voltage test contactor is triggered to close and enter the next step. The normal process of withstand voltage test is: connect the withstand voltage test AC contactor, if the withstand voltage test times out or does not meet the design requirements, the test is terminated, an error message is prompted and data is archived, if the withstand voltage test meets the design requirements, the withstand voltage test contactor is triggered to close and enter the next step. The timeout of the withstand voltage test is completed by the withstand voltage test count. Within the set withstand voltage test number, if the withstand voltage test is still unqualified, it is judged to be timed out, the withstand voltage NG indicator light is on, and the system automatically closes the withstand voltage test contactor, the corresponding station indicator light flashes, and the data is archived and recorded.

[0047] Specifically, Figure 7 As shown, in a preferred embodiment of the test method of the present invention, after the above-mentioned withstand voltage test items are completed, the turn-to-turn test is entered. When performing the turn-to-turn test, if the turn-to-turn test switch condition is on, the normal process of the turn-to-turn detection is entered. If the condition is off, the turn-to-turn test contactor is triggered to close and the next step is entered. The normal process of the turn-to-turn detection is: turn-to-turn detection AC contactor is connected. If the turn-to-turn detection times out or fails to meet the design requirements, the test is terminated, an error message is prompted and data is archived. If the design requirements are met, the turn-to-turn test contactor is triggered to close and the next step is entered. The turn-to-turn detection timeout is completed by the turn-to-turn test count. Within the set number of turn-to-turn tests, if the turn-to-turn test is still unqualified, it is determined to be a timeout, the turn-to-turn NG indicator light is on, and the system automatically closes the turn-to-turn test contactor, the corresponding station indicator light flashes, and the data is archived and recorded.

[0048] Specifically, Figure 8 and Fig. 9 As shown, in a preferred embodiment of the test method of the present invention, after the above-mentioned turn-to-turn test items are completed, the pressure test is entered. When the pressure test is performed, if the pressure test switch condition is on, the pressure start detection normal process is entered, and if the condition is off, the next step is entered. The normal process of pressurized start detection is: set the pressurized test power supply voltage / voltage frequency, then connect the test power supply AC contactor to determine whether the air pressure reaches the pressurized start design requirements or whether the current exceeds the limit. If it meets the design requirements, disconnect the test power supply AC contactor to shut down, delay for 2 seconds, and then connect the test power supply AC contactor to perform another pressurized start test. If the air pressure does not meet the design requirements, the test ends and an error message is prompted and data is archived. If it meets the design requirements, that is, the pressurized start is successful, close the test power supply contactor and start the drain solenoid valve. When it is lower than 10kPa, add 1 to the number of pressurized tests. When the number of pressurized tests does not reach the test number, close the drain solenoid valve, connect the test power supply contactor again, and perform a pressurized test cycle. If the number of pressurized tests reaches the test number, determine whether the air pressure is lower than 10kPa. When it is lower than 10kPa, close the drain solenoid valve and proceed to the next performance test item.

[0049] Specifically, Fig.10 and Fig.11 As shown, in a preferred embodiment of the test method of the present invention, after the above-mentioned pressure test items are completed, the performance test is entered. When performing the performance test, first set the standard test power supply voltage / voltage frequency, take a screenshot of the test power contactor, and then judge whether the current is over-limit, judge whether the air pressure reaches the air pressure standard + 10kPa, that is, judge whether the air pressure reaches the performance test design requirements or whether the current is over-limit, if yes, then close the test power contactor, and at the same time, the station indicator light flashes, and then start the drain solenoid valve, and the data is automatically recorded and archived. When the air pressure reaches the air pressure standard + 10kPa, open the drain solenoid valve, enable the PI control algorithm, enable the air pressure range detection, enable the air pressure fluctuation detection, judge the air pressure range and air pressure fluctuation, and after the air pressure is rated air pressure + 4kPa and the air pressure fluctuation is stable, perform temperature compensation, and then automatically archive the data, then start the drain solenoid valve, and then continue to judge the air pressure. When the air pressure is lower than 10kPa, close the drain solenoid valve and proceed to the next test item. That is, during the performance test, start the compressor and make it operate normally to the air pressure standard + 10kPa, open the exhaust solenoid valve, and record the current, power, flow, noise and other hard indicators after the exhaust reaches a steady state. If the recorded parameters do not meet the design requirements, unqualified information will be prompted. If the entire process test is completed normally and meets the standards, close the compressor and the exhaust solenoid valve and archive the data.

[0050] Specifically, the principles of the above-mentioned PI control algorithm, enabling air pressure range detection, and enabling air pressure fluctuation detection are: the air pressure in the air circuit is read in real time through a pressure gauge, and the analog quantity is transmitted to the controller, and the control value for controlling the opening size of the electric proportional valve is obtained through the PI algorithm. CurrentOUT is the output analog control value, which is used to control the opening size of the electric proportional valve. LLPV-LPV is the air pressure difference before and after the time period T_Cycle, PV-SV is the set air pressure and the actual air pressure difference before and after the time period T_Cycle, KP is the gain ratio, KI is the integral ratio, and LastOUT is the range parameter.

[0051] The specific steps include:

[0052] 1) Record the current air pressure value LPV at the first moment of the time cycle T_Cycle;

[0053] 2) Record the current air pressure value LLPV at the second moment of the time cycle T_Cycle, and calculate the air pressure change value between the first moment and the second moment of the same time cycle T_Cycle, as well as the difference between the current air pressure value PV and the target air pressure SV;

[0054] 3) Multiply the pressure change value (LLPV-LPV) between the first moment and the second moment by the gain ratio KP to obtain the first adjustment value Delta_P, then multiply the difference (PV-SV) between the current pressure value PV and the target pressure SV by the integral ratio KI to obtain the second adjustment value Delta_I, and add the speed adjustment value LastOUT to make the system quickly enter the rated pressure range and obtain the control value CurrentOUT used to control the electric proportional valve.

[0055] To prevent the regulation from getting out of control, there are also control thresholds MIN and MAX to constrain the boundary range of the output control value CurrentOUT. In order to make the air pressure control fast and stable, the gain ratio KP and integral ratio KI are dynamic values ​​and need to be tested and adjusted multiple times.

[0056] Furthermore, if Fig.12 As shown, when performing a stall test, set the simulated stall voltage and then connect the test power supply AC contactor. If the current exceeds the limit or the air pressure does not meet the design requirements, the test is terminated, the test power supply contactor is turned off, and the error message is prompted by the flashing of the work station indicator light. At the same time, the drain solenoid valve is started and data is archived. If the design requirements are met, that is, the air pressure reaches the stall air pressure standard, the test power supply contactor is turned off to shut down, and then the drain solenoid valve is started. The air pressure is judged again. If it is lower than 10kPa, the drain solenoid valve is closed and the test is terminated.

[0057] In summary, the test items of the test system and test method of the present invention cover performance tests of withstand voltage performance, turn-to-turn withstand voltage performance, start-up performance with pressure, stall performance, and performance tests of hard indicators such as current, power, flow, and noise during normal load operation. The parameters recorded in the running test can be automatically saved and archived, and the withstand voltage, turn-to-turn, start-up performance with pressure, stall, and simulated load tests are automatically converted to other test runs at the moment of completion. Reliable product data traceability enables the present invention to effectively improve test efficiency and data traceability when applied to field tests, reduce work intensity, and save human resources.

[0058] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions only describe the principles of the present invention. The present invention may have various changes and improvements without departing from the spirit and scope of the present invention, and these changes and improvements fall within the scope of the present invention to be protected, and the scope of protection claimed by the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for comprehensive testing of oil-free compressor performance based on an oil-free compressor performance comprehensive testing system, characterized in that: The oil-free compressor performance comprehensive testing system comprises: The system comprises a duplex station for accommodating two compressors to be tested, wherein the two compressors to be tested on the duplex station are connected to the same set of test assemblies, wherein the test assembly comprises an electrical test subassembly and a gas circuit test subassembly; The electrical test subassembly includes a withstand voltage test unit and an inter-turn test unit. The withstand voltage test unit is used to dynamically test the electrical insulation and withstand voltage between the rotor and the stator inside the compressor. The inter-turn test unit is used to test the insulation performance of the coil winding of the rotor inside the compressor. The gas circuit test subassembly includes a gas tank, a drainage solenoid valve is provided at the drainage port of the gas tank, and the exhaust pipeline of the gas tank is sequentially connected with an air pressure detection unit, an electrical proportional valve, a flow detection unit, an exhaust solenoid valve and a float flowmeter in the direction from upstream to downstream, and the withstand voltage test unit, the turn-to-turn test unit, the drainage solenoid valve, the air pressure detection unit, the electrical proportional valve, the flow detection unit, the exhaust solenoid valve and the float flowmeter are all connected with a PLC unit and a switch power supply, and the PLC unit is connected with a display module and a data archiving module; The compressor is connected to a variable frequency power supply, which is in communication connection with the PLC unit to provide a normal operating voltage or a withstand voltage test voltage for the compressor; It also includes a four-channel analog quantity input module, the four-channel analog quantity input module is connected to the voltage output end of the switching power supply, the analog signal output ends of the air pressure detection unit and the flow detection unit are respectively connected to the analog voltage input ends of the third channel and the fourth channel of the four-channel analog quantity input module, and the four-channel analog quantity input module is communicatively connected to the PLC unit; It also includes a two-channel analog output module, the air pressure adjustment signal output port of the electric proportional valve is connected to the current input port of the first channel of the two-channel analog output module, and the two-channel analog output module is communicatively connected to the PLC unit; Also included is a barcode scanner connected to the PLC unit serial port communication; The oil-free compressor performance comprehensive testing method comprises the following steps: S1. Power on the system, start the running configuration, call the corresponding product formula, log in the user, scan the product code and start the test; S2, perform withstand voltage test, turn-to-turn test, pressure test, performance test and locked rotor test. After the previous test is completed, the test relay corresponding to the next test is turned on, and the test relay of the previous test is reset, and the next test is automatically switched to. Abnormal test results are reported and data is archived; When performing the pressure test, if the pressure test switch condition is on, the normal process of pressure start detection is entered; if the condition is off, the next step is entered; the normal process of pressure start detection is: connect the test power supply AC contactor, judge whether the air pressure reaches the pressure start design requirements, if it reaches the design requirements, disconnect the test power supply AC contactor, delay 2 seconds and then connect the test power supply AC contactor to perform another pressure start test, if the air pressure does not reach the design requirements, end the test, prompt an error message and archive the data, if it meets the design requirements, enter the next step; When conducting the performance test, start the compressor and make it operate normally to the air pressure standard + 10kpa. Open the exhaust solenoid valve, and record the current, power, flow, and noise after the exhaust reaches a steady state. If the recorded parameters do not meet the design requirements, an unqualified message will be prompted. If the entire process test is completed normally and meets the standards, close the compressor and the exhaust solenoid valve and archive the data.

2. A comprehensive test method for oil-free compressor performance according to claim 1, characterized in that: When performing the withstand voltage test, if the withstand voltage test switch condition is on, the normal withstand voltage test process is entered; if the condition is off, the withstand voltage test AC contactor is triggered to close, and the next step is entered; the normal withstand voltage test process is: turn on the withstand voltage test AC contactor; if the withstand voltage test times out or does not meet the design requirements, the test is ended, an error message is prompted, and data is archived; if the design requirements are met, the withstand voltage test AC contactor is triggered to close, and the next step is entered.

3. The comprehensive performance testing method for an oil-free compressor according to claim 1, characterized in that: When performing the inter-turn test, if the inter-turn test switch condition is on, the normal inter-turn detection process is entered; if the condition is off, the inter-turn detection AC contactor is triggered to close, and the next step is entered; The normal process of turn-to-turn detection is: turn-on the turn-to-turn detection AC contactor. If the turn-to-turn detection times out or fails to meet the design requirements, the test ends, an error message is prompted, and data is archived. If the design requirements are met, the turn-to-turn detection AC contactor is turned off and the next step is entered.

4. The comprehensive performance testing method for an oil-free compressor according to claim 1, characterized in that: When performing the stall test, the simulated stall voltage is set and the test power supply AC contactor is turned on. If the current exceeds the limit or does not meet the design requirements, the test is terminated, an error message is prompted and data is archived. If the design requirements are met, the next step is entered.

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