System and method for testing anti-interference electricity tolerance characteristic of centrifugal pump

Abstract

The invention discloses a system and a method for testing the anti-interference electricity tolerance characteristic of a centrifugal pump, and the system comprises a power supply loop, a process loop and a fault recorder which are connected with one another, and the power supply loop comprises an interference electricity simulator, a frequency converter, a motor and a torque sensor. The voltage sag simulator is used for simulating three-phase short circuit, single-phase grounding short circuit faults, two-phase grounding short circuit faults and voltage drop characteristics of the two-phase short circuit faults. The process loop comprises a centrifugal pump, a first pressure gauge, a water tank, a second pressure gauge, an electric control valve and a turbine flowmeter. The influence of different interference electricity depths and time on performance parameters such as shaft power, lift and efficiency when various short circuit faults occur is reflected by detecting the torque change of the motor, the flow change of the centrifugal pump and the pressure change, and the technical response characteristics of the centrifugal pump under the interference electricity working condition are studied and tested to determine the interference electricity of the centrifugal pump. The research on the anti-interference electricity tolerance characteristic of the centrifugal pump is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of electrical equipment electric shaking testing, and in particular to a system and method for testing the anti-electrical shaking tolerance characteristics of a centrifugal pump. Background Art

[0002] Large petrochemical enterprises have the characteristics of high temperature and high pressure, flammable and explosive, complex process flow, difficult material balance, and high value of single equipment in the production process. Although petrochemical enterprises have high requirements for power supply continuity and reliability, due to the complex power supply and distribution system network, high power load density, uneven power equipment conditions, and harsh surrounding chemical pollution and corrosion environment, the probability of petrochemical enterprise power grids being impacted by external power grid failures, rain and lightning strikes, personnel operation accidents, and equipment failures has also increased accordingly. In the actual production process, in addition to direct power outages, more impacts are manifested in the reduction of power quality of the power supply system. According to authoritative statistics from the US Electric Power Research Institute (EPRI), power shaking events account for as much as 92% of the total power quality events.

[0003] In a continuous production system with complex processes, the impact of power supply system fluctuations on the process is huge: it causes the low-voltage motor group to stop running. After the grid voltage returns to normal, the motor group cannot automatically resume operation and needs to be restored by the cooperation of process and electrical personnel. Power supply system fluctuations can cause fluctuations in the production process of the device at the least, or interrupt the production process of the device at the worst, causing unplanned shutdowns, and sometimes even fires, explosions and other serious accidents. Therefore, studying the impact of power fluctuations on industrial processes has become one of the hot issues in domestic and international research.

[0004] In order to study the anti-swaying tolerance characteristics of centrifugal pumps, it is necessary to test the anti-swaying ability of centrifugal pumps. By measuring the changes in motor torque, flow rate and pressure of centrifugal pumps, the change patterns of performance parameters such as shaft power, head, efficiency, etc. at different depths and times of electric shaking when various short-circuit faults occur are obtained. The test system for the anti-swaying tolerance characteristics of centrifugal pumps should be composed of an electric shaking simulation device, a frequency converter, an electric motor, a centrifugal pump, an electric regulating valve, and a water tank. At the same time, the parameters should be measured by measuring instruments such as torque sensors, pressure gauges, and turbine flow meters. Therefore, establishing a test system and method for the anti-swaying tolerance characteristics of centrifugal pumps is of great significance for the study of the anti-swaying tolerance ability of centrifugal pump loads. Summary of the invention

[0005] In view of the above problems existing in the prior art, the present invention proposes a testing system and method for the anti-sway electrical tolerance characteristics of a centrifugal pump, which has a reasonable design, overcomes the shortcomings of the prior art, and has good effects.

[0006] In order to achieve the above purpose 1, the present invention adopts the following technical solution:

[0007] A test system for the anti-electrical shaking tolerance characteristics of a centrifugal pump comprises a power supply circuit, a process circuit and a fault recorder which are interconnected. The power supply circuit comprises an electric shaking simulator, a frequency converter, an electric motor and a torque sensor. The electric shaking simulator is used to simulate the voltage drop characteristics of a three-phase short circuit, a single-phase ground short circuit fault, a two-phase ground short circuit fault and a two-phase short circuit fault. The process circuit comprises a centrifugal pump, a first pressure gauge, a water tank, a second pressure gauge, an electric regulating valve and a turbine flowmeter.

[0008] Furthermore, in the power supply circuit, the electric sway simulator, the frequency converter, the motor and the torque sensor are connected in sequence, and the torque sensor is connected to the process circuit.

[0009] Furthermore, in the process loop, the outlet of the centrifugal pump is connected to a first pressure gauge, and the inlet thereof is connected to a second pressure gauge. The first pressure gauge is connected to a water tank inlet, and the second pressure gauge is connected to a water tank outlet via an electric regulating valve and a turbine flowmeter.

[0010] Furthermore, the centrifugal pump is also connected to a torque sensor.

[0011] Furthermore, channel 1 and channel 2 of the fault recorder are connected to voltage and current probes, and the voltage and current probes are respectively connected to the output terminals of the motor for recording voltage and current.

[0012] Furthermore, the channel 3 of the fault recorder is connected to the torque sensor via a signal conversion probe for recording the rotation speed.

[0013] Furthermore, channel 4 and channel 5 of the fault recorder are respectively connected to the first pressure gauge and the second pressure gauge through a signal conversion probe, so as to record the inlet and outlet pressures of the centrifugal pump.

[0014] Furthermore, the channel 6 of the fault recorder is connected to the turbine flowmeter via a signal conversion probe for recording the flow rate.

[0015] In order to achieve the above purpose 2, the present invention adopts the following technical solution:

[0016] A method for testing the anti-swaying electrical tolerance characteristics of a centrifugal pump, using a testing system for the anti-swaying electrical tolerance characteristics of a centrifugal pump as described above, comprises the following steps:

[0017] Step 1: Check the power status, complete the construction of the test system and the wiring of each device in the power-off state, and record the basic information of the power sway simulator and fault recorder;

[0018] Step 2: Connect the output of the sway simulator to the main wiring of the motor, and the voltage and current probes of the fault recorder to the output terminals of the motor respectively. Meanwhile, connect the torque sensor, the first pressure gauge, the second pressure gauge, and the turbine flowmeter to the recorder in sequence. By setting the output, observe the signal output of the fault recorder, the start-up of the centrifugal pump, the opening of the electric regulating valve, and whether the flow, pressure, and speed signal recordings are normal. Check the operation of the above instruments and prepare for the test.

[0019] Step 3: Test the status signal of the centrifugal pump under different power fluctuation conditions;

[0020] Step 4: Test the status signal of the sway simulator when different types of short circuit faults occur in the centrifugal pump. By adjusting the drop mode in the sway simulator, set the fault type to single-phase ground short circuit fault, two-phase ground short circuit fault and two-phase short circuit fault in sequence, and repeat step 3;

[0021] Step 5: After the experiment, the data signals collected in the experiment are analyzed and sorted, and the process response characteristics of the centrifugal pump under the power swing condition are analyzed. The process response characteristics include shaft power, head and efficiency.

[0022] Furthermore, in step 3, the following testing process is included:

[0023] When the three-phase output of the power sway simulator is normal, observe the voltage, current, speed, flow rate, and pressure signals, use a fault recorder to record the waveform, and record related data;

[0024] When the three-phase power swing amplitude is set to 90% and the output is 0.3s, observe the voltage, current, speed, flow rate, and pressure signals, use a fault recorder to record the waveform, and record related data;

[0025] When the three-phase power swing amplitude is set to 90% and the output is 0.5s, observe the voltage, current, speed, flow rate, and pressure signals, use a fault recorder to record the waveform, and record related data;

[0026] When the three-phase power swing amplitude is set to 90% and the output is 1s, observe the voltage, current, speed, flow rate, and pressure signals, use a fault recorder to record the waveform, and record related data;

[0027] When the three-phase power swing amplitude is set to 85%, set the output to 0.3s, 0.5s, and 1s respectively, observe the voltage, current, speed, flow, and pressure signals, use a fault recorder to record the waveform, and record the relevant data;

[0028] When the power swing decreases by 5% in sequence, set the output to 0.3s, 0.5s, and 1s respectively, observe the voltage, current, speed, flow, and pressure signals, use a fault recorder to record the waveforms, and record related data.

[0029] Further, in step 5, the head refers to the effective head obtained by the centrifugal pump per unit mass of liquid, and its formula is:

[0030]

[0031] Among them, P D is the pressure of the section where the first pressure gauge is located;

[0032] P S is the pressure of the section where the second pressure gauge is located;

[0033] Z D is the height of the first pressure gauge;

[0034] Z S is the height of the second pressure gauge;

[0035] C D is the average flow rate of the liquid at the outlet of the centrifugal pump;

[0036] C S is the average liquid flow rate at the centrifugal pump inlet;

[0037] ρ is the liquid density;

[0038] g is the acceleration due to gravity;

[0039]

[0040] Wherein, DD is the inner diameter of the outlet pipe;

[0041] Q is the flow rate;

[0042]

[0043] Where DS is the inner diameter of the inlet pipe.

[0044] Further, in step 5, the shaft power N 轴 It refers to the work that the motor provides to the pump shaft of the centrifugal pump per unit time. The shaft power is measured by a torque sensor, and the formula is:

[0045] N 轴 =M·ω;

[0046] Where, M is the torque;

[0047] ω is the angular velocity of the pump shaft,

[0048] n is the pump shaft speed;

[0049] Further, in step 5, the pump efficiency of the centrifugal pump is the ratio of effective power to shaft power, and its formula is:

[0050]

[0051] Among them, N e is the effective power.

[0052] Beneficial technical effects brought by the present invention:

[0053] The present invention establishes a system and method for testing the anti-electrical shaking tolerance characteristics of a centrifugal pump. By detecting the changes in motor torque, centrifugal pump flow rate and pressure, it reflects the influence of different electric shaking depths and times on performance parameters such as shaft power, head and efficiency when various short-circuit faults occur. By studying and testing the process response characteristics of the centrifugal pump under electric shaking conditions, the research on the anti-electrical shaking tolerance characteristics of the centrifugal pump is realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 A schematic diagram of a test system for the anti-sway electrical withstand characteristics of a centrifugal pump in the present invention; DETAILED DESCRIPTION

[0055] The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. Instead, they are merely examples of methods consistent with some aspects of the present disclosure as detailed in the appended claims.

[0056] The terms used in this disclosure are for the purpose of describing characteristic embodiments only and are not intended to limit the disclosure. The singular forms "a", "the" and "the" used in this disclosure and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0057] The specific implementation of the present invention is further described below in conjunction with specific embodiments:

[0058] At present, the research on the influence of power supply system power shaking on the transient characteristics of centrifugal pumps mainly studies the mechanical characteristics by establishing an equivalent circuit and analyzing the balance relationship between electromagnetic torque and mechanical torque. Studies have shown that there is a critical speed for the motor speed. When the actual speed is greater than the critical speed, the motor can recover to the stable state before the power shaking occurs. If the actual speed is less than the critical speed, it will cause the contactor to trip, the motor will trip and the power will be cut off, and the centrifugal pump will not work normally.

[0059] In addition to affecting the mechanical characteristics of the centrifugal pump, electric shaking will also affect performance parameters such as shaft power, head, and efficiency through changes in the flow rate and pressure of the centrifugal pump.

[0060] At the same time, the main causes of electric shaking are short circuit faults, lightning strikes, and induction motor starting. According to the analysis of fault cases, short circuit faults are the main cause of electric shaking. Therefore, in order to study the anti-electrical shaking tolerance characteristics of centrifugal pumps, the change rules of performance parameters at different electric shaking depths and times when three-phase short circuit, single-phase ground short circuit, two-phase ground short circuit and two-phase short circuit occur are carried out to study and test the process response characteristics of centrifugal pumps under electric shaking conditions.

[0061] A centrifugal pump anti-sway withstand characteristics test system, such as Figure 1 As shown, it includes a power supply circuit, a process circuit and a fault recorder connected to each other, the power supply circuit includes a shaking simulator, a frequency converter, a motor and a torque sensor, the shaking simulator, the frequency converter, the motor and the torque sensor are connected in sequence, the torque sensor is connected to the process circuit, and the shaking simulator is used to simulate the voltage drop characteristics of three-phase short circuit, single-phase ground short circuit fault, two-phase ground short circuit fault and two-phase short circuit fault;

[0062] The process loop includes a centrifugal pump, a first pressure gauge, a water tank, a second pressure gauge, an electric regulating valve and a turbine flowmeter; the outlet of the centrifugal pump is connected to the first pressure gauge, and the inlet of the centrifugal pump is connected to the second pressure gauge, the first pressure gauge is connected to the water tank inlet, the second pressure gauge is connected to the water tank outlet through the electric regulating valve and the turbine flowmeter, and the centrifugal pump is connected to the torque sensor in the power supply loop.

[0063] The fault recorder is used to collect various signals and waveforms. Its channel 1 and channel 2 are connected to the voltage and current probes, which are respectively connected to the output terminals of the motor to record the voltage and current.

[0064] Channel 3 of the fault recorder is connected to the torque sensor through a signal conversion probe to record the rotational speed;

[0065] Channel 4 and channel 5 of the fault recorder are connected to the first pressure gauge and the second pressure gauge respectively through a signal conversion probe to record the inlet and outlet pressures of the centrifugal pump;

[0066] Channel 6 of the fault recorder is connected to the turbine flowmeter through a signal conversion probe to record the flow rate;

[0067] Channels 1-6 of the fault recorder can collect and store voltage and current signals, speed signals, inlet and outlet pressure signals and flow signals during the power swing process through probes.

[0068] A method for testing the anti-swaying electrical tolerance characteristics of a centrifugal pump, using a testing system for the anti-swaying electrical tolerance characteristics of a centrifugal pump as described above, comprises the following steps:

[0069] Step 1: Check the power status, complete the construction of the test system and the wiring of each device in the power-off state, and record the basic information of the power sway simulator and fault recorder;

[0070] Step 2: Connect the output of the sway simulator to the main wiring of the motor, and the voltage and current probes of the fault recorder to the output terminals of the motor respectively. Meanwhile, connect the torque sensor, the first pressure gauge, the second pressure gauge, and the turbine flowmeter to the recorder in sequence. By setting the output, observe the signal output of the fault recorder, the start-up of the centrifugal pump, the opening of the electric regulating valve, and whether the flow, pressure, and speed signal recordings are normal. Check the operation of the above instruments and prepare for the test.

[0071] Step 3: Test the status signal of the centrifugal pump under different power fluctuation conditions;

[0072] The testing process includes the following:

[0073] When the three-phase output of the power sway simulator is normal, observe the voltage, current, speed, flow rate, and pressure signals, use a fault recorder to record the waveform, and record related data;

[0074] When the three-phase power swing amplitude is set to 90% and the output is 0.3s, observe the voltage, current, speed, flow rate, and pressure signals, use a fault recorder to record the waveform, and record related data;

[0075] When the three-phase power swing amplitude is set to 90% and the output is 0.5s, observe the voltage, current, speed, flow rate, and pressure signals, use a fault recorder to record the waveform, and record related data;

[0076] When the three-phase power swing amplitude is set to 90% and the output is 1s, observe the voltage, current, speed, flow rate, and pressure signals, use a fault recorder to record the waveform, and record related data;

[0077] When the three-phase power swing amplitude is set to 85%, set the output to 0.3s, 0.5s, and 1s respectively, observe the voltage, current, speed, flow, and pressure signals, use a fault recorder to record the waveform, and record the relevant data;

[0078] When the power swing decreases by 5% in sequence, set the output to 0.3s, 0.5s, and 1s respectively, observe the voltage, current, speed, flow, and pressure signals, use a fault recorder to record the waveforms, and record related data.

[0079] Step 4: Test the status signal of the sway simulator when different types of short circuit faults occur in the centrifugal pump. By adjusting the drop mode in the sway simulator, set the fault type to single-phase ground short circuit fault, two-phase ground short circuit fault and two-phase short circuit fault in sequence, and repeat step 3;

[0080] Step 5: After the experiment is over, analyze and organize the data signals collected during the experiment.

[0081] The above test system and test method can be used to obtain the changes in motor torque, flow rate and pressure of centrifugal pump under different shaking depths and times when various short-circuit faults occur. In order to further analyze the process response characteristics of the centrifugal pump under shaking conditions, the following formula is needed to further obtain performance parameters such as shaft power, head and efficiency:

[0082] (1) Lift H

[0083] The head refers to the effective energy head obtained by a centrifugal pump per unit mass of liquid, and the unit is m.

[0084]

[0085] Among them, P D is the pressure of the section where the first pressure gauge is located, Pa;

[0086] P S is the pressure of the section where the second pressure gauge is located, Pa;

[0087] ρ is the liquid density;

[0088] g is the acceleration due to gravity;

[0089] Z D is the height of the first pressure gauge;

[0090] Z S is the height of the second pressure gauge;

[0091] C D is the average flow rate of the liquid at the outlet of the centrifugal pump;

[0092] C S is the average liquid flow rate at the centrifugal pump inlet;

[0093] ∑h DS is the flow resistance loss, which is ignored and is 0;

[0094]

[0095] Among them, DD is the inner diameter of the outlet pipe, and Q is the flow rate;

[0096]

[0097] Where DS is the inner diameter of the inlet pipe.

[0098] (2) Shaft power

[0099] The shaft power of a centrifugal pump refers to the work done by the motor on the pump shaft of the centrifugal pump per unit time. The shaft power is measured by a torque sensor and is

[0100] N 轴 =M·ω;

[0101] Where, M is the torque;

[0102] ω Angular velocity of goose meat pump shaft, rad / s,

[0103] n is the pump shaft speed, rpm.

[0104] (3) Efficiency

[0105] The pump efficiency of a centrifugal pump is the ratio of effective power to shaft power:

[0106]

[0107] Among them, N e is the effective power;

[0108] N 轴 is the shaft power.

[0109] Example 1

[0110] A test system for anti-swaying tolerance characteristics of a centrifugal pump, comprising a power supply circuit, a process circuit and a fault recorder connected to each other, the power supply circuit comprising a swaying simulator, a frequency converter, a motor and a torque sensor, the swaying simulator, the frequency converter, the motor and the torque sensor are connected in sequence, the torque sensor is connected to the process circuit, and the swaying simulator is used to simulate voltage drop characteristics of three-phase short circuit, single-phase ground short circuit fault, two-phase ground short circuit fault and two-phase short circuit fault;

[0111] The process loop includes a centrifugal pump, a first pressure gauge, a water tank, a second pressure gauge, an electric regulating valve and a turbine flowmeter; the outlet of the centrifugal pump is connected to the first pressure gauge, and the inlet of the centrifugal pump is connected to the second pressure gauge, the first pressure gauge is connected to the water tank inlet, the second pressure gauge is connected to the water tank outlet through the electric regulating valve and the turbine flowmeter, and the centrifugal pump is connected to the torque sensor in the power supply loop.

[0112] The fault recorder is used to collect various signals and waveforms. Its channel 1 and channel 2 are connected to the voltage and current probes, which are respectively connected to the output terminals of the motor to record the voltage and current.

[0113] Channel 3 of the fault recorder is connected to the torque sensor through a signal conversion probe to record the rotational speed;

[0114] Channel 4 and channel 5 of the fault recorder are connected to the first pressure gauge and the second pressure gauge respectively through a signal conversion probe to record the inlet and outlet pressures of the centrifugal pump;

[0115] Channel 6 of the fault recorder is connected to the turbine flowmeter through a signal conversion probe to record the flow rate;

[0116] Channels 1-6 of the fault recorder can collect and store voltage and current signals, speed signals, inlet and outlet pressure signals and flow signals during the power swing process through probes.

[0117] A method for testing the anti-swaying electrical tolerance characteristics of a centrifugal pump, using a testing system for the anti-swaying electrical tolerance characteristics of a centrifugal pump as described above, comprises the following steps:

[0118] Step 1: Check the power status, complete the construction of the test system and the wiring of each device in the power-off state, and record the basic information of the power sway simulator and fault recorder;

[0119] Step 2: Connect the output of the sway simulator to the main wiring of the motor, and the voltage and current probes of the fault recorder to the output terminals of the motor respectively. Meanwhile, connect the torque sensor, the first pressure gauge, the second pressure gauge, and the turbine flowmeter to the recorder in sequence. By setting the output, observe the signal output of the fault recorder, the start-up of the centrifugal pump, the opening of the electric regulating valve, and whether the flow, pressure, and speed signal recordings are normal. Check the operation of the above instruments and prepare for the test.

[0120] Step 3: Test the status signal of the centrifugal pump under different power fluctuation conditions;

[0121] The testing process includes the following:

[0122] When the three-phase output of the power sway simulator is normal, observe the voltage, current, speed, flow rate, and pressure signals, use a fault recorder to record the waveform, and record related data;

[0123] When the three-phase power swing amplitude is set to 90% and the output is 0.3s, observe the voltage, current, speed, flow rate, and pressure signals, use a fault recorder to record the waveform, and record related data;

[0124] When the three-phase power swing amplitude is set to 90% and the output is 0.5s, observe the voltage, current, speed, flow rate, and pressure signals, use a fault recorder to record the waveform, and record related data;

[0125] When the three-phase power swing amplitude is set to 90% and the output is 1s, observe the voltage, current, speed, flow rate, and pressure signals, use a fault recorder to record the waveform, and record related data;

[0126] When the three-phase power swing amplitude is set to 85%, set the output to 0.3s, 0.5s, and 1s respectively, observe the voltage, current, speed, flow, and pressure signals, use a fault recorder to record the waveform, and record the relevant data;

[0127] When the power swing decreases by 5% in sequence, set the output to 0.3s, 0.5s, and 1s respectively, observe the voltage, current, speed, flow, and pressure signals, use a fault recorder to record the waveforms, and record related data.

[0128] Step 4: Test the status signal of the sway simulator when different types of short circuit faults occur in the centrifugal pump. By adjusting the drop mode in the sway simulator, set the fault type to single-phase ground short circuit fault, two-phase ground short circuit fault and two-phase short circuit fault in sequence, and repeat step 3;

[0129] Step 5: After the experiment is over, analyze and organize the data signals collected during the experiment.

[0130] The above test system and test method can be used to obtain the changes in motor torque, flow rate and pressure of centrifugal pump under different shaking depths and times when various short-circuit faults occur. In order to further analyze the process response characteristics of the centrifugal pump under shaking conditions, the following formula is needed to further obtain performance parameters such as shaft power, head and efficiency:

[0131] (1) Lift H

[0132] Head refers to the effective energy head obtained by a centrifugal pump per unit mass of liquid, with the unit being m. The formula is:

[0133]

[0134] Among them, P D is the pressure of the section where the first pressure gauge is located, Pa;

[0135] P S is the pressure of the section where the second pressure gauge is located, Pa;

[0136] ρ is the liquid density;

[0137] g is the acceleration due to gravity;

[0138] Z D is the height of the first pressure gauge;

[0139] Z S is the height of the second pressure gauge;

[0140] C D is the average flow rate of the liquid at the outlet of the centrifugal pump;

[0141] C Sis the average liquid flow rate at the centrifugal pump inlet;

[0142] ∑h DS is the flow resistance loss, which is ignored and is 0;

[0143]

[0144] DD is the inner diameter of the outlet pipe, in this embodiment DD = 53.0 mm;

[0145] Q is the flow rate;

[0146]

[0147] DS is the inner diameter of the inlet pipe, in this embodiment DS = 72.0 mm;

[0148] (2) Shaft power

[0149] The shaft power of a centrifugal pump refers to the work done by the motor on the pump shaft of the centrifugal pump per unit time. The shaft power is measured by a torque sensor and is

[0150] N 轴 =M·ω;

[0151] Where, M is the torque;

[0152] ω Angular velocity of goose meat pump shaft, rad / s,

[0153] n is the pump shaft speed, rpm.

[0154] (3) Efficiency

[0155] The pump efficiency of a centrifugal pump is the ratio of effective power to shaft power:

[0156]

[0157] Among them, N e is the effective power;

[0158] N 轴 is the shaft power.

[0159] Example 2

[0160] A test system for anti-swaying tolerance characteristics of a centrifugal pump, comprising a power supply circuit, a process circuit and a fault recorder connected to each other, the power supply circuit comprising a swaying simulator, a frequency converter, a motor and a torque sensor, the swaying simulator, the frequency converter, the motor and the torque sensor are connected in sequence, the torque sensor is connected to the process circuit, and the swaying simulator is used to simulate voltage drop characteristics of three-phase short circuit, single-phase ground short circuit fault, two-phase ground short circuit fault and two-phase short circuit fault;

[0161] The process loop includes a centrifugal pump, a first pressure gauge, a water tank, a second pressure gauge, an electric regulating valve and a turbine flowmeter; the outlet of the centrifugal pump is connected to the first pressure gauge, and the inlet of the centrifugal pump is connected to the second pressure gauge, the first pressure gauge is connected to the water tank inlet, the second pressure gauge is connected to the water tank outlet through the electric regulating valve and the turbine flowmeter, and the centrifugal pump is connected to the torque sensor in the power supply loop.

[0162] The fault recorder is used to collect various signals and waveforms. Its channel 1 and channel 2 are connected to the voltage and current probes, which are respectively connected to the output terminals of the motor to record the voltage and current.

[0163] Channel 3 of the fault recorder is connected to the torque sensor through a signal conversion probe to record the rotational speed;

[0164] Channel 4 and channel 5 of the fault recorder are connected to the first pressure gauge and the second pressure gauge respectively through a signal conversion probe to record the inlet and outlet pressures of the centrifugal pump;

[0165] Channel 6 of the fault recorder is connected to the turbine flowmeter through a signal conversion probe to record the flow rate;

[0166] Channels 1-6 of the fault recorder can collect and store voltage and current signals, speed signals, inlet and outlet pressure signals and flow signals during the power swing process through probes.

[0167] A method for testing the anti-swaying electrical tolerance characteristics of a centrifugal pump, using a testing system for the anti-swaying electrical tolerance characteristics of a centrifugal pump as described above, comprises the following steps:

[0168] Step 1: Check the power status, complete the construction of the test system and the wiring of each device in the power-off state, and record the basic information of the power sway simulator and fault recorder;

[0169] Step 2: Connect the output of the sway simulator to the main wiring of the motor, and the voltage and current probes of the fault recorder to the output terminals of the motor respectively. Meanwhile, connect the torque sensor, the first pressure gauge, the second pressure gauge, and the turbine flowmeter to the recorder in sequence. By setting the output, observe the signal output of the fault recorder, the start-up of the centrifugal pump, the opening of the electric regulating valve, and whether the flow, pressure, and speed signal recordings are normal. Check the operation of the above instruments and prepare for the test.

[0170] Step 3: Test the status signal of the centrifugal pump under different power fluctuation conditions;

[0171] The testing process includes the following:

[0172] When the three-phase output of the power sway simulator is normal, observe the voltage, current, speed, flow rate, and pressure signals, use a fault recorder to record the waveform, and record related data;

[0173] When the three-phase power swing amplitude is set to 90% and the output is 0.3s, observe the voltage, current, speed, flow rate, and pressure signals, use a fault recorder to record the waveform, and record related data;

[0174] When the three-phase power swing amplitude is set to 90% and the output is 0.5s, observe the voltage, current, speed, flow rate, and pressure signals, use a fault recorder to record the waveform, and record related data;

[0175] When the three-phase power swing amplitude is set to 90% and the output is 1s, observe the voltage, current, speed, flow rate, and pressure signals, use a fault recorder to record the waveform, and record related data;

[0176] When the three-phase power swing amplitude is set to 85%, set the output to 0.3s, 0.5s, and 1s respectively, observe the voltage, current, speed, flow, and pressure signals, use a fault recorder to record the waveform, and record the relevant data;

[0177] When the power swing decreases by 5% in sequence, set the output to 0.3s, 0.5s, and 1s respectively, observe the voltage, current, speed, flow, and pressure signals, use a fault recorder to record the waveforms, and record related data.

[0178] Step 4: Test the status signal of the sway simulator when different types of short circuit faults occur in the centrifugal pump. By adjusting the drop mode in the sway simulator, set the fault type to single-phase ground short circuit fault, two-phase ground short circuit fault and two-phase short circuit fault in sequence, and repeat step 3;

[0179] Step 5: After the experiment is over, analyze and organize the data signals collected during the experiment.

[0180] The above test system and test method can be used to obtain the changes in motor torque, flow rate and pressure of centrifugal pump under different shaking depths and times when various short-circuit faults occur. In order to further analyze the process response characteristics of the centrifugal pump under shaking conditions, the following formula is needed to further obtain performance parameters such as shaft power, head and efficiency:

[0181] (1) Lift H

[0182] Head refers to the effective energy head obtained by a centrifugal pump per unit mass of liquid, with the unit being m. The formula is:

[0183]

[0184] Among them, P D is the pressure of the section where the first pressure gauge is located, Pa;

[0185] P Sis the pressure of the section where the second pressure gauge is located, Pa;

[0186] ρ is the liquid density;

[0187] g is the acceleration due to gravity;

[0188] Z D is the height of the first pressure gauge;

[0189] Z S is the height of the second pressure gauge;

[0190] C D is the average flow rate of the liquid at the outlet of the centrifugal pump;

[0191] C S is the average liquid flow rate at the centrifugal pump inlet;

[0192] ∑h DS is the flow resistance loss, which is ignored and is 0;

[0193]

[0194] DD is the inner diameter of the outlet pipe, in this embodiment DD = 53.0 mm;

[0195] Q is the flow rate;

[0196]

[0197] DS is the inner diameter of the inlet pipe, in this embodiment DS = 72.0 mm;

[0198] (2) Shaft power

[0199] The shaft power of a centrifugal pump refers to the work done by the motor on the pump shaft of the centrifugal pump per unit time. The shaft power is measured by a torque sensor and is

[0200] N 轴 =M·ω;

[0201] Where, M is the torque;

[0202] ω Angular velocity of goose meat pump shaft, rad / s,

[0203] n is the pump shaft speed, rpm.

[0204] (3) Efficiency

[0205] The pump efficiency of a centrifugal pump is the ratio of effective power to shaft power:

[0206]

[0207] Among them, N e is the effective power;

[0208] N 轴 is the shaft power.

[0209] The above describes the preferred embodiments of the present invention. It should be understood that the present invention is not limited to the above-mentioned specific embodiments, and the devices and structures that are not described in detail should be understood to be implemented in a common manner in the art; any technician familiar with the art can use the above-disclosed methods and technical contents to make many possible changes and modifications to the technical solutions of the present invention without departing from the scope of the technical solutions of the present invention, or modify them into equivalent embodiments of equivalent changes, which does not affect the essential content of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention are still within the scope of protection of the technical solutions of the present invention.

Claims

1. A centrifugal pump anti-sway withstand characteristics test system, characterized in that: It includes a power supply circuit, a process circuit and a fault recorder that are interconnected. The power supply circuit includes a sway simulator, a frequency converter, a motor and a torque sensor. The sway simulator is used to simulate the voltage drop characteristics of a three-phase short circuit, a single-phase ground short circuit fault, a two-phase ground short circuit fault and a two-phase short circuit fault. The process circuit includes a centrifugal pump, a first pressure gauge, a water tank, a second pressure gauge, an electric regulating valve and a turbine flowmeter.

2. A centrifugal pump anti-sway withstand characteristic test system according to claim 1, characterized in that: In the power supply circuit, the sway simulator, the frequency converter, the motor and the torque sensor are connected in sequence, and the torque sensor is connected to the process circuit.

3. A centrifugal pump anti-sway withstand characteristic test system according to claim 2, characterized in that: In the process loop, the outlet of the centrifugal pump is connected to the first pressure gauge, and the inlet thereof is connected to the second pressure gauge. The first pressure gauge is connected to the water tank inlet, and the second pressure gauge is connected to the water tank outlet through an electric regulating valve and a turbine flowmeter.

4. A centrifugal pump anti-sway withstand characteristic test system according to claim 3, characterized in that: The centrifugal pump is also connected to a torque sensor.

5. A centrifugal pump anti-sway withstand characteristic test system according to claim 1, characterized in that: Channel 1 and channel 2 of the fault recorder are connected to voltage and current probes, and the voltage and current probes are respectively connected to the output terminals of the motor for recording voltage and current.

6. A centrifugal pump anti-sway withstand characteristic testing system according to claim 1, characterized in that: The channel 3 of the fault recorder is connected to the torque sensor through a signal conversion probe for recording the rotation speed.

7. A centrifugal pump anti-sway withstand characteristic testing system according to claim 1, characterized in that: Channel 4 and channel 5 of the fault recorder are respectively connected to the first pressure gauge and the second pressure gauge through a signal conversion probe, so as to record the inlet and outlet pressures of the centrifugal pump.

8. A centrifugal pump anti-sway withstand characteristic testing system according to claim 1, characterized in that: The channel 6 of the fault recorder is connected to the turbine flowmeter through a signal conversion probe for recording the flow rate.

9. A method for testing the anti-sway electrical withstand characteristics of a centrifugal pump, characterized in that: A test system for the anti-sway electrical tolerance characteristics of a centrifugal pump as claimed in any one of claims 1 to 8 comprises the following steps: Step 1: Check the power status, complete the construction of the test system and the wiring of each device in the power-off state, and record the basic information of the power sway simulator and fault recorder; Step 2: Connect the output of the sway simulator to the main wiring of the motor, and the voltage and current probes of the fault recorder to the output terminals of the motor respectively. Meanwhile, connect the torque sensor, the first pressure gauge, the second pressure gauge, and the turbine flowmeter to the recorder in sequence. By setting the output, observe the signal output of the fault recorder, the start-up of the centrifugal pump, the opening of the electric regulating valve, and whether the flow, pressure, and speed signal recordings are normal. Check the operation of the above instruments and prepare for the test. Step 3: Test the status signal of the centrifugal pump under different power fluctuation conditions; Step 4: Test the status signal of the sway simulator when different types of short circuit faults occur in the centrifugal pump. By adjusting the drop mode in the sway simulator, set the fault type to single-phase ground short circuit fault, two-phase ground short circuit fault and two-phase short circuit fault in sequence, and repeat step 3; Step 5: After the experiment, the data signals collected in the experiment are analyzed and sorted, and the process response characteristics of the centrifugal pump under the power swing condition are analyzed. The process response characteristics include shaft power, head and efficiency.

10. A method for testing the anti-sway electrical withstand characteristics of a centrifugal pump according to claim 1, characterized in that: In step 3, the following testing procedures are included: When the three-phase output of the power sway simulator is normal, observe the voltage, current, speed, flow rate, and pressure signals, use a fault recorder to record the waveform, and record related data; When the three-phase power swing amplitude is set to 90% and the output is 0.3s, observe the voltage, current, speed, flow rate, and pressure signals, use a fault recorder to record the waveform, and record related data; When the three-phase power swing amplitude is set to 90% and the output is 0.5s, observe the voltage, current, speed, flow rate, and pressure signals, use a fault recorder to record the waveform, and record related data; When the three-phase power swing amplitude is set to 90% and the output is 1s, observe the voltage, current, speed, flow rate, and pressure signals, use a fault recorder to record the waveform, and record related data; When the three-phase power swing amplitude is set to 85%, set the output to 0.3s, 0.5s, and 1s respectively, observe the voltage, current, speed, flow, and pressure signals, use a fault recorder to record the waveform, and record the relevant data; When the power sway is reduced by 5% in sequence, set the output to 0.3s, 0.5s, and 1s respectively, observe the voltage, current, speed, flow, and pressure signals, use a fault recorder to record the waveform, and record the relevant data.

11. A method for testing the anti-sway electrical withstand characteristics of a centrifugal pump according to claim 1, characterized in that: In step 5, the head refers to the effective head obtained by the centrifugal pump per unit mass of liquid, and its formula is: Among them, P D is the pressure of the section where the first pressure gauge is located, P S is the pressure of the section where the second pressure gauge is located, Z D is the height of the first pressure gauge, Z S is the height of the second pressure gauge, C D and C S are the average flow rates of the liquid at the outlet and inlet of the centrifugal pump, ρ is the liquid density, and g is the acceleration of gravity; Among them, DD is the inner diameter of the outlet pipe, and Q is the flow rate; Where DS is the inner diameter of the inlet pipe.

12. A method for testing the anti-sway electrical withstand characteristics of a centrifugal pump according to claim 11, characterized in that: In step 5, the shaft power N 轴 It refers to the work that the motor provides to the pump shaft of the centrifugal pump per unit time. The shaft power is measured by a torque sensor, and the formula is: N 轴 =M·ω; Where M is the torque, ω is the angular velocity of the pump shaft, n is the pump shaft speed.

13. A method for testing the anti-sway electrical withstand characteristics of a centrifugal pump according to claim 12, characterized in that: In step 5, the pump efficiency of the centrifugal pump is the ratio of effective power to shaft power, and its formula is: Among them, N e is the effective power.

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