CN103089597A - Control method of high-pressure variable-frequency water pump system - Google Patents
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- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 title claims abstract description 93
- 238000000034 method Methods 0.000 title claims abstract description 18
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 32
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 21
- 239000010949 copper Substances 0.000 claims description 21
- 229910052802 copper Inorganic materials 0.000 claims description 21
- 229910052742 iron Inorganic materials 0.000 claims description 16
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Abstract
The invention discloses a control method of a high-pressure variable-frequency water pump system. The control method is used for control of total losses of the water pump system, and the total losses comprise losses of a phase-shifting transformer, losses of a high-voltage inverter, losses of an asynchronous motor, losses of a high pressure water pump, and ineffective kinetic energy losses of water. By means of the control method, the operating characteristic curve of the high-voltage inverter is optimized, and effects of energy conservation and emission reduction are achieved.
Description
Technical Field
The invention relates to a full-environment energy-saving control method for a high-voltage frequency converter of a water pump system.
Background
In an electric power system, a motor is widely used in various fields such as industrial and agricultural production, national defense, science and technology, and social life as a main power device. The motor load accounts for 60-70% of the total generated energy and becomes the electrical equipment with the most electricity consumption; a variable frequency power supply adopting power electronic technology is used for supplying power to high-energy-consumption equipment such as a fan, a water pump and the like, and 282 billion kWh of electricity can be saved every year. The variable frequency speed control technology has a mainstream development direction due to the obvious electricity saving effect, higher power supply factor, excellent speed control performance and wide applicability, and particularly has a very wide market prospect in the application of large-capacity high-voltage variable frequency speed control devices in domestic metallurgy, steel, petroleum, chemical industry, water treatment, mines, electric power and other industries such as dragging fans, pumps, compressors and various large-scale machines.
The traditional variable frequency speed regulation technology mainly solves the problem of optimized operation of a motor, and aims at specific working conditions, namely specific energy conversion systems, such as refrigeration plus room size, air blowing plus heat dissipation effect, water pumping plus time speed and the like, the final target after energy conversion is consistent, but the electric energy consumption in the implementation process is different.
Disclosure of Invention
The invention aims to provide a full-environment energy-saving control method of a high-voltage frequency converter applied to a water pump system.
In order to solve the technical problems, the invention provides a control method of a high-voltage variable-frequency water pump system, which is used for controlling the total loss of the water pump system, including the loss of a phase-shifting transformer, the loss of a high-voltage frequency converter, the loss of an asynchronous motor, the loss of a high-pressure water pump and the loss of ineffective kinetic energy of water.
The loss of the phase-shifting transformer, namely the loss of the phase-shifting transformer needs to be established with a mathematical model, the loss of the transformer is approximate to the loss of the fundamental wave, and the total loss of the phase-shifting transformer is the copper lossP Cu1Iron lossP Fe1And stray lossesP OSLSaid copper lossP Cu1Calculating transformer losses for resistive losses and winding eddy current lossesP TRLComprises the following steps:
wherein,I TRis the primary side current of the transformer,R TRis the resistance of the transformer.
The loss step of the high-voltage frequency converter, namely establishing a loss mathematical model of the high-voltage frequency converter, including switching lossP swAnd loss of on stateP on. Wherein switching lossesP swAnd the switching frequencyf swDC voltage of power unitU DCAnd asynchronous motor stator currentI sCorrelated, on-state lossesP onOn-resistance with IGBTR dsStator current of asynchronous motorI sAnd (4) correlating. Calculating high voltage frequency converter lossP MVCThe formula of (1) is:
the loss of the asynchronous motor is analyzed, a mathematical model of the loss is established,calculating the copper and iron losses of the asynchronous motor by the equivalent circuit of the asynchronous motor, wherein the copper loss of the asynchronous motor comprises stator copper loss, rotor copper loss and total copper lossP CuComprises the following steps:
stator iron loss of asynchronous motorP FeComprises the following steps:
wherein, f swhich is the frequency of the stator of the motor,φis the air-gap magnetic flux,αthe value of the number is 1.3,βthe value was 2.
Due to the flow of the water pipevRotor frequency of asynchronous machinef rIs proportional, i.e.
The iron loss and the iron loss of the asynchronous motor can be obtaineds、vThe relationship between them is:
the loss of the high-pressure water pump is mathematically modeled by the loss of the high-pressure water pump system:
high-pressure water pumpEfficiency of (2)ηCan be described as flowvThe second order curve of (a) is,a、b、crespectively, the efficiency coefficients.
The mechanical power output by the asynchronous motor is as follows:
calculating to obtain the power loss of the high-pressure water pumpP pumpComprises the following steps:
the invalid kinetic energy loss of the water is analyzed, and since the kinetic energy of the water volume finally pumped to the height h is invalid, the kinetic energy of the water volume pumped to the height h in unit time is regarded as loss, and the invalid kinetic energy loss of the water is calculated as follows:
the loss of the phase-shifting transformer, the high-voltage frequency converter, the asynchronous motor and the loss of the ineffective kinetic energy of the high-pressure water pump and the water are accumulated, and the total loss of the high-voltage frequency conversion water pump system is obtained as follows:
further, according to the active power balance equation, the input active power of the phase-shifting transformer is equal to the sum of the loss of the phase-shifting transformer, the loss of the high-voltage frequency converter and the input power of the asynchronous motor:
where cos phi denotes the input power factor of the phase shifting transformer.
The equivalent resistance on the stator side can be obtained from the equivalent circuit of the asynchronous motor as follows:
thereby, can push outI TRAndI sthe relationship between them is:
。
by an equivalent circuit of an asynchronous machineI sAndI 0、I rthe relationship of (1) is:
still further, the mechanical power output by the asynchronous motor is equal to the sum of the kinetic energy loss of water and the potential energy of water:
further calculation to obtainI rComprises the following steps:
thus, further calculation yieldsI sComprises the following steps:
still further, the total loss of the high-pressure variable-frequency water pump system isP LossExpressed as:
variables ofsAndva function of, i.e.
。
Obtaining the slip ratio corresponding to the minimum system losssAnd flow ratev：
The control steps of the water pump system are as follows.
Measuring the internal resistance of the phase-shifting transformer, measuring the on-state resistance of a power tube for high-voltage frequency conversion, and performing a switch test.
And step two, testing the parameters of the equivalent circuit of the asynchronous motor to obtain specific values of all the parameters in the equivalent circuit.
And step three, carrying out efficiency test on the selected water pump, determining the values of variables a, b and c in a quadratic curve of the selected water pump, and determining the pipe diameter and the pumping height value through an actual water pump system.
And step four, establishing a mathematical model of the whole water pump system according to the obtained parameters, and solving a minimum value of the function.
Step five, according to the corresponding minimum values、vAnd the asynchronous motor is controlled by the high-voltage frequency converter, so that the water pump system operates in an energy-saving state.
The control method of the high-voltage variable-frequency water pump system has the beneficial effects that:
the full-environment energy-saving control method of the high-voltage frequency converter of the water pump system optimizes the operating characteristic curve of the high-voltage frequency converter and achieves the effects of energy conservation and emission reduction.
Drawings
FIG. 1 is a schematic diagram of a high-pressure variable-frequency water pump system according to the present invention.
Fig. 2 is an equivalent circuit diagram of an asynchronous motor in the high-voltage variable-frequency water pump system.
Detailed Description
As shown in fig. 1 and 2, a control method of a high-voltage variable-frequency water pump system controls the total loss of the water pump system, including the loss of a phase-shifting transformer, the loss of a high-voltage frequency converter, the loss of an asynchronous motor, the loss of a high-pressure water pump, and the loss of ineffective kinetic energy of water.
Firstly, a mathematical model is required to be established for the loss of the phase-shifting transformer, the power factor of the phase-shifting transformer is very high, the influence of harmonic loss is neglected, and the loss of the transformer is the loss of fundamental wave, so that the total loss of the phase-shifting transformer is divided into copper lossP Cu1Iron lossP Fe1And stray lossesP OSL1Three parts of which copper is lostP Cu1And can be divided into resistance loss and winding eddy current loss, only iron lossP FeVoltage dependent, copper lossP Cu1 And stray lossesP OSL1Because the primary side current of the phase-shifting transformer is fixed, the iron loss of the transformer can be regarded as a fixed value. Losses of transformersP TRLComprises the following steps:
wherein,I TRis the primary side current of the transformer,R TRis the resistance of the transformer.
The stray loss and the iron loss are 20% -30% of the load loss, and the possible conversion coefficient is 0.25.
Secondly, a mathematical model of the loss of the high-voltage frequency converter, including the switching loss, needs to be establishedP swAnd loss of on stateP on。
Switching lossesP swAnd the switching frequencyf swDC voltage of power unitU DCAnd asynchronous motor stator currentI sAbout, expressed as:
loss of on stateP onSimplified IGBT on-state resistanceR dsThe loss of (c) is:
。
thirdly, the loss of the asynchronous motor needs to be analyzed, a mathematical model of the loss is established, the copper loss and the iron loss of the asynchronous motor can be calculated through an equivalent circuit of the asynchronous motor, and the copper loss of the asynchronous motor comprises stator copper loss and rotor copper loss;
the rotor copper loss is:
the stator iron loss of the asynchronous motor is as follows:
then, the efficiency of the high pressure water pump needs to be mathematically modeled for losses in the water pump systemηCan be described as flowvThe second order curve of (a) is,a、b、crespectively, the efficiency coefficients.
The mechanical power output by the asynchronous motor can be expressed as:
the power loss of the high-pressure water pump can be obtainedP pumpComprises the following steps:
again, the kinetic energy loss of water that is lost is analyzed, and since the amount of water that is eventually pumped to height h has an ineffective kinetic energy, the kinetic energy of the amount of water pumped to height h per unit time is considered lost and is expressed as:
and finally, accumulating the loss of each part to obtain the total loss of the high-voltage variable-frequency water pump system as follows:
according to the active power balance equation, the input active power of the phase-shifting transformer is equal to the sum of the loss of the phase-shifting transformer, the loss of the high-voltage frequency converter and the input power of the asynchronous motor:
wherein cos phi represents the input power factor of the phase-shifting transformer, and the input power factor of the phase-shifting transformer is 0.95.
The equivalent resistance on the stator side can be obtained from the equivalent circuit of the asynchronous motor as follows:
thereby, can push outI TRAndI sthe relationship between them is:
。
from asynchronous electricityThe equivalent circuit of the machine canI sAndI 0、I rthe relationship of (1) is:
，
because the mechanical power output by the asynchronous motor is equal to the sum of the kinetic energy loss of water and the potential energy of water, the mechanical power is expressed as follows:
by further derivation, it can be obtainedI rComprises the following steps:
thus, further derivation, one can obtainI sComprises the following steps:
finally, the total loss of the high-voltage variable-frequency water pump system isP LossCan be expressed as variablessAndvi.e.:
。
to sum upIn order to obtain the efficiency optimal point of the high-voltage variable-frequency water pump system, namely, a function is obtained
So that the slip corresponding to the minimum system loss can be obtained by solving the following equationsAnd flow ratev。
The accuracy of the mathematical model of the water pump system involved in the content of the invention is closely related to the values of all parameters, so that all parameters need to be accurately measured according to actual circuit parameters and working conditions, and the control steps of the water pump system are as follows.
Measuring the internal resistance of the phase-shifting transformer, measuring the on-state resistance of a power tube for high-voltage frequency conversion, and performing a switch test.
And step two, testing the parameters of the equivalent circuit of the asynchronous motor to obtain specific values of all the parameters in the equivalent circuit.
And step three, carrying out efficiency test on the selected water pump, determining the values of variables a, b and c in a quadratic curve of the selected water pump, and determining the pipe diameter and the pumping height value through an actual water pump system.
And step four, establishing a mathematical model of the whole water pump system according to the obtained parameters, and solving a minimum value of the function.
Step five, according to the corresponding minimum values、vAnd the asynchronous motor is controlled by the high-voltage frequency converter, so that the water pump system operates in the optimal energy-saving state.
The above embodiments are merely illustrative of the present invention and are not intended to be limiting, and variations and modifications of the above embodiments are within the scope of the present invention.
Claims (6)
1. The utility model provides a control method of high pressure frequency conversion water pump system, controls water pump system's total loss, including the loss of phase-shifting transformer, the loss of high-voltage inverter, asynchronous machine loss and the loss of high pressure water pump and the invalid kinetic energy loss of water, its characterized in that:
the loss of the phase-shifting transformer, namely the loss of the phase-shifting transformer needs to be established with a mathematical model, the loss of the transformer is approximate to the loss of the fundamental wave, and the total loss of the phase-shifting transformer is the copper lossP Cu1Iron lossP Fe1And stray lossesP OSLLoss of phase-shifting transformerP TRLComprises the following steps:
wherein,I TRis the primary side current of the transformer,R TRis the resistance of the transformer;
loss of the high-voltage frequency converter, namely, a mathematical model of loss of the high-voltage frequency converter needs to be established, including switching lossP swAnd loss of on stateP onWherein switching lossesP swAnd the switching frequencyf swDC voltage of power unitU DCAnd asynchronous motor stator currentI sCorrelated, on-state lossesP onOn-resistance with IGBTR dsStator current of asynchronous motorI sCorrelation;
calculating high voltage frequency converter lossP MVCThe formula of (1) is:
the loss of the asynchronous motor is analyzed, a mathematical model of the loss is established, the equivalent circuit of the asynchronous motor is used for calculating the copper loss and the iron loss of the asynchronous motor, the copper loss of the asynchronous motor comprises stator copper loss and rotor copper loss, and the total copper lossP CuComprises the following steps:
stator iron loss of asynchronous motorP FeComprises the following steps:
wherein, f swhich is the frequency of the stator of the motor,φis the air-gap magnetic flux,αthe value of the number is 1.3,βthe value is 2;
due to the flow of the water pipevRotor frequency of asynchronous machinef rIn direct proportion, namely:
the iron loss and the iron loss of the asynchronous motor can be obtaineds、vThe relationship between them is:
the loss of the high-pressure water pump is mathematically modeled by the loss of the high-pressure water pump system:
efficiency of high pressure water pumpηCan be described as flowvThe second order curve of (a) is,a、b、crespectively representing efficiency coefficients;
the mechanical power output by the asynchronous motor is as follows:
calculating to obtain the power loss of the high-pressure water pumpP pumpIs composed of
The invalid kinetic energy loss of the water is analyzed, and since the kinetic energy of the water volume finally pumped to the height h is invalid, the kinetic energy of the water volume pumped to the height h in unit time is regarded as loss, and the invalid kinetic energy loss of the water is calculated as follows:
2. the control method of the high-pressure variable-frequency water pump system according to claim 1, characterized in that: the loss of the phase-shifting transformer, the high-voltage frequency converter, the asynchronous motor and the loss of the ineffective kinetic energy of the high-pressure water pump and the water are accumulated, and the total loss of the high-voltage frequency conversion water pump system is obtained as follows:
3. the control method of the high-pressure variable-frequency water pump system according to claim 1 or 2, characterized by comprising the following steps: according to the active power balance equation, the input active power of the phase-shifting transformer is equal to the sum of the loss of the phase-shifting transformer, the loss of the high-voltage frequency converter and the input power of the asynchronous motor:
wherein cos phi represents the input power factor of the phase-shifting transformer;
the equivalent resistance on the stator side can be obtained from the equivalent circuit of the asynchronous motor as follows:
thereby, can push outI TRAndI sthe relationship between them is:
by an equivalent circuit of an asynchronous machineI sAndI 0、I rthe relationship of (1) is:
4. the control method of the high-pressure variable-frequency water pump system according to claim 1 or 2, characterized by comprising the following steps: the mechanical power output by the asynchronous motor is equal to the sum of kinetic energy loss of water and potential energy of the water:
further calculation to obtainI rComprises the following steps:
thus, further calculation yieldsI sComprises the following steps:
5. the control method of the high-pressure variable-frequency water pump system according to claim 1, characterized in that: the total loss of the high-voltage variable-frequency water pump system isP LossExpressed as:
variables ofsAndva function of, i.e.
Obtaining the slip ratio corresponding to the minimum system losssAnd flow ratev：
6. The control method of the high-pressure variable-frequency water pump system according to claim 1, characterized in that: the control steps of the water pump system are as follows:
measuring the internal resistance of a phase-shifting transformer, measuring the on-state resistance of a power tube for high-voltage frequency conversion, and performing a switch test;
testing parameters of the equivalent circuit of the asynchronous motor to obtain specific values of all the parameters in the equivalent circuit;
thirdly, carrying out efficiency test on the selected water pump, and determining the variable in a quadratic curve of the selected water pumpa、b、cThe value of (2) is determined by the actual water pump system according to the pipe diameter and the water pumping height value;
establishing a mathematical model of the whole water pump system according to the obtained parameters, and solving a minimum value of a function;
step five, according to the corresponding minimum values、vAnd the asynchronous motor is controlled by the high-voltage frequency converter, so that the water pump system operates in an energy-saving state.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107725350A (en) * | 2017-10-09 | 2018-02-23 | 湖南银河电气有限公司 | State monitoring apparatus with the online efficiency evaluation and test of pump |
| CN110555249A (en) * | 2019-08-20 | 2019-12-10 | 湖南大学 | motor parameter design method based on global optimal water pump load annual loss power consumption |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0333495A (en) * | 1989-06-29 | 1991-02-13 | Toshiba Corp | Control device for condensate pump |
| US5160244A (en) * | 1989-08-08 | 1992-11-03 | Hitachi, Ltd. | Pump system operable by variable-speed control |
| CN101340164A (en) * | 2008-05-06 | 2009-01-07 | 镇江华东电力设备制造厂 | High-voltage frequency transformer energy feeding braking device |
| JP4312913B2 (en) * | 1999-12-20 | 2009-08-12 | 千代田化工建設株式会社 | Pump system |
| CN201918739U (en) * | 2010-12-28 | 2011-08-03 | 上海赉珂博工业设备有限公司 | Energy-storage-type electricity-saving control device of water pump |
-
2012
- 2012-12-31 CN CN201210584229.5A patent/CN103089597B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0333495A (en) * | 1989-06-29 | 1991-02-13 | Toshiba Corp | Control device for condensate pump |
| US5160244A (en) * | 1989-08-08 | 1992-11-03 | Hitachi, Ltd. | Pump system operable by variable-speed control |
| JP4312913B2 (en) * | 1999-12-20 | 2009-08-12 | 千代田化工建設株式会社 | Pump system |
| CN101340164A (en) * | 2008-05-06 | 2009-01-07 | 镇江华东电力设备制造厂 | High-voltage frequency transformer energy feeding braking device |
| CN201918739U (en) * | 2010-12-28 | 2011-08-03 | 上海赉珂博工业设备有限公司 | Energy-storage-type electricity-saving control device of water pump |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107725350A (en) * | 2017-10-09 | 2018-02-23 | 湖南银河电气有限公司 | State monitoring apparatus with the online efficiency evaluation and test of pump |
| CN107725350B (en) * | 2017-10-09 | 2020-04-07 | 湖南银河电气有限公司 | State monitoring device with online energy efficiency evaluation of pump |
| CN110555249A (en) * | 2019-08-20 | 2019-12-10 | 湖南大学 | motor parameter design method based on global optimal water pump load annual loss power consumption |
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