Self-starting simulation test method and system based on converted iron loss of variable-speed pumped storage unit

Abstract

The invention discloses a self-starting simulation test method based on conversion of iron loss of a variable-speed pumped storage unit. The method comprises the following steps: acquiring related electrical state data of the variable-speed pumped storage unit; carrying out simplified calculation on the iron loss of the motor in an impedance parameter (Z parameter) conversion mode; building an alternating-current excitation motor model of the variable-speed pumped storage unit; and simulating and testing the self-starting performance of the variable-speed pumped storage unit under different starting control parameters. According to the method, simplified calculation is carried out on the iron loss of the motor in an impedance parameter (Z parameter) conversion mode, an accurate alternating-current excitation motor model is built, the iron loss resistance and the excitation reactance are adjusted by using conversion factors, transition parameters and parameters of a final simplified equivalent model are considered, and the calculation accuracy is improved. Therefore, the model can reflect the actual working state of the motor more truly, and the simulation test of the self-starting performance under different starting control parameters is realized.

Description

Technical Field

[0001] The invention relates to the field of self-starting of a double-fed variable-speed pumped-storage unit, and in particular to a self-starting simulation test method and system based on converting the iron loss of a variable-speed pumped-storage unit. Background Art

[0002] Pumped storage power stations are the main way to store large amounts of electricity at present, with peak-shaving, valley-filling, frequency regulation and emergency standby functions. With the advancement of UHV construction and the increase in clean energy installed capacity, the demand for variable-speed pumped storage units is becoming increasingly urgent. This type of unit can quickly respond to grid demand, improve grid stability and power quality, while improving its own efficiency, stability and power regulation capabilities. Especially when operating at an appropriate speed, it can significantly reduce wear, increase annual average efficiency by 3% to 5%, and extend the unit maintenance cycle.

[0003] However, the inverter output in the variable speed pumped storage unit contains abundant harmonics, which increases the iron loss of the motor and affects the efficiency and self-starting control. In order to simplify the model and improve the experimental accuracy, the study of the iron loss of the variable speed pumped storage unit and its self-starting test method is particularly important. However, directly connecting a large motor from a stationary state to the power grid will cause magnetic saturation and impact current, which may burn the motor. Therefore, considering the difference in starting methods between variable speed units and traditional constant speed units, it is necessary to specifically study their control strategies.

[0004] In view of the high risk of conducting self-starting tests directly on real machines, we propose a simulation model self-starting test method based on the converted iron loss of doubly-fed variable-speed pumped-storage units to reduce the risk and provide a solution. Summary of the invention

[0005] In view of the problems existing in the prior art, the present invention is proposed.

[0006] Therefore, the problem to be solved by the present invention is to verify the control parameter setting problem of the AC excitation system controlling the variable-speed pumped-storage motor to complete the whole process from self-starting in a non-stationary state to synchronous grid connection. The method of directly testing the real machine is replaced by the experimental method of the model. The control parameters are set in sections according to the actual speed of the motor during the starting process, which can achieve a better starting effect. The model of the motor iron loss under consideration makes the test results more consistent with the actual engineering conditions.

[0007] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0008] In the first aspect, an embodiment of the present invention provides a self-starting simulation test method based on converting the iron loss of a variable-speed pumped-storage unit, which includes obtaining relevant electrical state data of the variable-speed pumped-storage unit; simplifying the calculation of the motor iron loss by converting impedance parameters (Z parameters); building an AC excitation motor model of a variable-speed pumped-storage unit; and simulating and testing the self-starting performance of the variable-speed pumped-storage unit under different starting control parameters.

[0009] As a preferred scheme of the self-starting simulation test method based on the conversion of the iron loss of the variable-speed pumped-storage unit described in the present invention, the relevant electrical status data of the variable-speed pumped-storage unit is obtained, including the electrical parameters of the variable-speed pumped-storage unit, such as rated power, rated capacity, rated voltage, rated current, rated excitation current, rated frequency, number of magnetic poles, direct-axis inductance, quadrature-axis inductance, self-inductance of the excitation winding, mutual inductance of the stator winding and the excitation winding, stator resistance, and excitation winding resistance.

[0010] As a preferred solution of the self-starting simulation test method based on the conversion of the iron loss of the variable speed pumped storage unit according to the present invention, wherein: the motor iron loss is simplified by converting the impedance parameter (Z parameter), which is expressed as

[0011] Let the transformation factor be:

[0012]

[0013] Where Δ is the transformation factor, R Fe is the iron loss resistance, j is the imaginary unit, X m is the magnetizing reactance before transformation;

[0014] The excitation branch is approximated by multiplying the modulus of the transformation factor, and the final equivalent parameters are:

[0015]

[0016] Among them, Z final is the parameter matrix of the final simplified equivalent model, z 1 、z 2 are the transition parameters of the transition equivalent model respectively.

[0017] As a preferred solution of the self-starting simulation test method based on the conversion of the iron loss of the variable speed pumped storage unit described in the present invention, wherein: the AC excitation motor model of the variable speed pumped storage unit is constructed, which is expressed as

[0018] make

[0019] Δz 1 =R s +jX s

[0020] Δz2 =R r +jX r

[0021] JXj m |Δ|=jωL m

[0022] Among them, z 1 、z 2 are the transition parameters of the transition equivalent model, R s , R r are the stator resistance and rotor resistance of the final simplified equivalent model, X s , X r are the stator reactance and rotor reactance of the final simplified equivalent model, ω is the grid frequency, L m is the magnetizing inductance;

[0023] The final simplified model is obtained.

[0024] As a preferred scheme of the self-starting simulation test method based on the conversion of iron loss of variable-speed pumped-storage units described in the present invention, wherein: the simulation and test of the self-starting performance of the variable-speed pumped-storage units under different starting control parameters includes the electrical connection of the motor, excitation control and the configuration of the frequency converter.

[0025] As a preferred solution of the self-starting simulation test method based on the conversion of iron loss of variable-speed pumped storage units described in the present invention, the electrical connection of the motor includes the power grid being connected to the stator winding of the doubly-fed motor on one side through a step-down transformer; and the other side being connected to the rotor winding of the motor through an excitation transformer through a three-level converter with an AC-DC-AC structure; and a DC voltage source being connected in parallel to each of the capacitors of the upper and lower half bridges on the DC side of the converter.

[0026] As a preferred scheme of the self-starting simulation test method based on the conversion of iron loss of variable-speed pumped storage units described in the present invention, the configuration of the excitation control and the frequency converter includes considering the resistance torque during the motor starting process, raising the DC side voltage of the frequency converter to 1.3 times the normal operating voltage during the self-starting stage, and the AC excitation system controls the motor to self-start from a stationary state, and tests four groups of starting parameters, namely, the control parameter is reduced to 0.7 times, the control parameter remains unchanged, the control parameter is increased to 2 times, and the control parameter is set in segments according to the motor speed.

[0027] In a second aspect, an embodiment of the present invention provides a multi-resource inertia and primary frequency regulation auxiliary service sequential acquisition system, which includes a data acquisition module, an iron loss conversion module, a motor model building module, and a self-starting simulation test module;

[0028] The data acquisition module is used to obtain relevant electrical status data of the variable speed pumped storage unit, including electrical parameters of the variable speed pumped storage unit, such as rated power, rated capacity, rated voltage, rated current, rated excitation current, rated frequency, number of magnetic pole pairs, direct axis inductance, quadrature axis inductance, excitation winding self-inductance, stator winding and excitation winding mutual inductance, stator resistance, excitation winding resistance;

[0029] The iron loss conversion module is used to simplify the calculation of the motor iron loss by converting the impedance parameter (Z parameter), and approximate the excitation branch by multiplying the conversion factor modulus value to obtain the final simplified equivalent parameter;

[0030] The motor model building module is used to build an AC excitation motor model of a variable speed pumped storage unit to obtain a final simplified model;

[0031] The self-starting simulation test module is used to simulate and test the self-starting performance of the variable speed pumped storage unit under different starting control parameters, including the electrical connection of the motor, excitation control and the configuration of the frequency converter, and to test different starting parameters.

[0032] In a third aspect, an embodiment of the present invention provides a computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: when the computer program instructions are executed by the processor, the steps of the self-starting simulation test method based on the converted iron loss of the variable-speed pumped storage unit as described in the first aspect of the present invention are implemented.

[0033] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein: when the computer program instructions are executed by a processor, the steps of the self-starting simulation test method based on the converted iron loss of a variable-speed pumped storage unit as described in the first aspect of the present invention are implemented.

[0034] The beneficial effects of the present invention are as follows: by obtaining the electrical parameters of the variable speed pumped storage unit, a basis is provided for subsequent simulation tests, ensuring the accuracy and reliability of the simulation. The motor iron loss is simplified by converting the impedance parameter (Z parameter), and the iron loss resistance and excitation reactance are adjusted by using the conversion factor, which simplifies the calculation process, improves the calculation efficiency, and maintains the accuracy of the calculation results. By establishing an AC excitation motor model, considering the transition parameters and the parameters of the final simplified equivalent model, the model can more realistically reflect the actual working state of the motor, and achieves accurate simulation of the motor performance. By simulating the self-starting performance under different starting control parameters, the starting performance of the unit is evaluated and optimized under different working conditions, ensuring that the unit can be reliably started under various conditions. The present invention realizes comprehensive optimization and control of the performance of the variable speed pumped storage unit, improves the starting efficiency and operating stability of the unit, reduces operating costs, and extends the service life of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0036] Figure 1 It is a flow chart of the self-starting simulation test method based on the conversion of the iron loss of the variable speed pumped storage unit;

[0037] Figure 2 It is a computer equipment diagram of the self-starting simulation test method based on the conversion of the iron loss of the variable speed pumped storage unit;

[0038] Figure 3 The structure diagram of the variable speed pumped storage unit is based on the self-starting simulation test method of the variable speed pumped storage unit iron loss conversion.

[0039] Figure 4 This is the equivalent circuit diagram of the doubly-fed generator based on the self-starting simulation test method for converting the iron loss of the variable-speed pumped storage unit.

[0040] Figure 5 This is the equivalent model diagram before the transformation of the self-starting simulation test method based on the converted iron loss of the variable-speed pumped storage unit.

[0041] Figure 6 This is a transition equivalent model diagram of the self-starting simulation test method based on the converted iron loss of the variable-speed pumped storage unit.

[0042] Figure 7 This is the final simplified equivalent model diagram of the self-starting simulation test method based on the converted iron loss of the variable-speed pumped storage unit. DETAILED DESCRIPTION

[0043] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0044] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0045] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0046] Example 1

[0047] Reference Figure 1 to Figure 7 , which is the first embodiment of the present invention, and provides a self-starting simulation test method based on the conversion of the iron loss of a variable speed pumped storage unit, comprising:

[0048] S1: Obtain relevant electrical status data of the variable speed pumped storage unit.

[0049] Furthermore, the electrical status data related to the variable-speed pumped-storage unit is obtained, including electrical parameters of the variable-speed pumped-storage unit, such as rated power, rated capacity, rated voltage, rated current, rated excitation current, rated frequency, number of pole pairs, direct-axis inductance, quadrature-axis inductance, self-inductance of the excitation winding, mutual inductance of the stator winding and the excitation winding, stator resistance, and excitation winding resistance.

[0050] It should be noted that variable speed pumped storage units refer to pumped storage units with adjustable speed. Compared with fixed speed units, they have stronger peak and frequency regulation capabilities and higher operating efficiency. Figure 3 As shown, the main circuit includes a double-fed machine 100 and a pump-turbine 200 using AC excitation, the control circuit includes a monitoring system 300, an AC excitation control system 400, a speed control system 500 and a guide vane 600, and the overall structure is also provided with a box-changing switch 700, a pumping switch 800 and a power generation switch 900;

[0051] The monitoring system 300 also includes a coordination controller 301 and a monitoring backend 302;

[0052] The AC excitation control system 400 is provided with a grid side 401 and a generator side 402;

[0053] The box-changing switch 700 is provided with a water pumping switch 701 and a power generation switch 702 respectively.

[0054] It should also be noted that obtaining accurate electrical parameters, such as rated power, rated voltage, resistance and inductance of each winding, is the basis for establishing an accurate motor model and directly affects the reliability of the simulation results. This provides data support for subsequent iron loss calculation and motor model construction, ensuring the accuracy of the simulation results.

[0055] S2: Simplify the calculation of motor iron loss by converting impedance parameters (Z parameters).

[0056] Furthermore, the motor iron loss is simplified by converting the impedance parameter (Z parameter), which is expressed as:

[0057] Let the transformation factor be:

[0058]

[0059] Where Δ is the transformation factor, R Fe is the iron loss resistance, j is the imaginary unit, X m is the magnetizing reactance before transformation;

[0060] The excitation branch is approximated by multiplying the modulus of the transformation factor, and the final equivalent parameters are:

[0061]

[0062] Among them, Z final is the parameter matrix of the final simplified equivalent model, z 1 、z 2 are the transition parameters of the transition equivalent model respectively.

[0063] It should be noted that the Figure 4 ω mentioned in r is the rotor angular velocity +, ψ r is the rotor flux; Figure 7 L mentioned in s , L r They are the stator inductance and rotor inductance of the final simplified equivalent model.

[0064] It should be noted that in the traditional doubly-fed asynchronous motor equivalent circuit, the motor iron loss is represented by a resistor with a constant resistance, which can accurately reflect the motor iron loss under rated conditions, such as Figure 4 shown.

[0065] The purpose of simplifying the model is to convert the steady-state Figure 4 The iron loss resistance connected in parallel at both ends of the excitation inductance is converted to the stator and rotor branches, and the iron loss resistance and the excitation reactance are connected in parallel, such as Figure 5 shown. Figure 6 is a simplified transition equivalent model, Figure 6 and Figure 5 Comparative equivalent calculations are performed to obtain the final simplified model.

[0066] Figure 5 and Figure 6 The Z parameter matrices of the equivalent models are:

[0067]

[0068] Among them, Z 11is the parameter matrix of the equivalent model before transformation; Z 21 is the parameter matrix of the transition equivalent model; R 1 , R 2 , are the stator resistance and rotor resistance of the equivalent model before transformation; X 1 , X 2 They are the stator reactance and rotor reactance of the equivalent model before transformation.

[0069] If Z 11 With Z 21 Equivalent, that is

[0070]

[0071] Further:

[0072]

[0073] have to:

[0074]

[0075] It should be noted that iron loss refers to the energy loss in the motor core, mainly including hysteresis loss and eddy current loss; impedance parameter (Z parameter) conversion refers to a circuit analysis method that simplifies the circuit structure and facilitates calculation by equivalently transforming the impedance parameters of circuit elements. In the present invention, impedance parameter (Z parameter) conversion is used to simplify the calculation of motor iron loss.

[0076] It should also be noted that the motor iron loss is simplified by converting the impedance parameter (Z parameter), and the complex iron loss model is equivalent to a simple circuit parameter, which significantly reduces the calculation complexity and improves the simulation efficiency. Fe and magnetizing reactance X m This simplified method greatly shortens the simulation time while ensuring the simulation accuracy, and has important practical value.

[0077] S3: Build a variable speed pumped storage unit AC excitation motor model;

[0078] Furthermore, a variable speed pumped storage unit AC excitation motor model is constructed, which is expressed as:

[0079] make

[0080] Δz 1 =R s +jX s

[0081] Δz 2 =R r +jX r

[0082] JXj m |Δ|=jωL m

[0083] Among them, z 1 、z 2 are the transition parameters of the transition equivalent model, R s , R r are the stator resistance and rotor resistance of the final simplified equivalent model, X s , X r are the stator reactance and rotor reactance of the final simplified equivalent model, ω is the grid frequency, L m is the excitation inductance; the final simplified model is as follows Figure 7 shown.

[0084] It should be noted that an accurate AC excitation motor model is built based on a simplified iron loss model and the obtained electrical parameters. This model can accurately reflect the operating characteristics of the motor under different working conditions and provide a reliable platform for subsequent self-starting simulation. 1 and Δz 2 , the parameters of the transition equivalent model are converted into the parameters of the final simplified model, which further simplifies the model structure and improves the computational efficiency.

[0085] S4: Simulate and test the self-starting performance of variable-speed pumped storage units under different starting control parameters;

[0086] Furthermore, the self-starting performance of the variable-speed pumped storage unit under different starting control parameters is simulated and tested, including the electrical connection of the motor, excitation control and the configuration of the inverter.

[0087] Furthermore, the electrical connection of the motor includes the grid being connected to the stator winding of the doubly-fed motor through a step-down transformer on one side; and the other side being connected to the rotor winding of the motor through an excitation transformer via a three-level converter of an AC-DC-AC structure; and a DC voltage source being connected in parallel to each of the capacitors of the upper and lower half bridges on the DC side of the converter.

[0088] Furthermore, the excitation control and inverter configuration include considering the resistance torque during motor starting, raising the inverter DC side voltage to 1.3 times the normal operating voltage during the self-starting stage, and the AC excitation system controlling the motor to self-start from a stationary state. Four groups of starting parameters are tested, namely, the control parameter is reduced to 0.7 times, the control parameter remains unchanged, the control parameter is increased to 2 times, and the control parameter is set in segments according to the motor speed.

[0089] It should be noted that the motor model input in the simulation software RSCAD sets the stator resistance, stator inductance, rotor resistance, rotor inductance and excitation inductance parameters after iron loss conversion, and sets the stator winding short-circuit stator voltage to zero, while adopting stator flux orientation. Among them, the typical parameters are set as follows:

[0090] Doubly-fed generator parameters: rated capacity is 336MVA; rated voltage is 15.75kV; stator resistance (per unit value) is 0.002; stator inductance (per unit value) is 0.112; rotor resistance (per unit value) is 0.003; rotor inductance (per unit value) is 0.143; excitation inductance (per unit value) is 2.701; moment of inertia is 2.23MWs / MVA;

[0091] Power supply parameters: line voltage effective value is 500kV; internal resistance is 0.0001Ω;

[0092] Step-down transformer parameters: rated capacity is 400MVA; transformation ratio is 500 / 15.75kV; reactance (unit value) is 0.1;

[0093] Excitation transformer parameters: rated capacity is 60MVA; transformation ratio is 15.75 / 4.5kV; reactance (unit value) is 0.1;

[0094] Resistance, inductance and capacitance parameters: the stator side grid-connected resistance is 0.0001Ω; the grid side converter AC side resistance is 0.0001Ω; the grid side converter AC side inductance is 400μH; the machine side converter AC side resistance is 0.0001Ω; the machine side converter AC side inductance is 400μH; the converter DC side capacitance is 18mF.

[0095] It should be noted that, taking into account the resistance torque during the motor starting process, the DC side voltage of the inverter is raised to 1.3 times the normal operating voltage during the self-starting stage. The AC excitation system controls the motor to self-start from a stationary state to determine the final data. The most suitable set of parameters tested by testing four sets of starting parameters is selected.

[0096] It should be noted that the self-starting performance of the variable-speed pumped storage unit under different starting control parameters, such as the DC side voltage of the frequency converter, the excitation control parameters, etc., is simulated and tested, the self-starting process of the motor under different working conditions is simulated, and its performance indicators, such as starting time, starting current, etc., are tested. This helps to optimize the starting control strategy and improve the starting reliability and efficiency of the unit. The method of setting control parameters in sections proposed in the present invention can dynamically adjust the control parameters according to the motor speed, realize more refined starting control, and further improve the starting performance.

[0097] The present invention discloses a self-starting simulation test method based on the conversion of variable speed pumped storage unit iron loss, aiming to improve the accuracy and efficiency of variable speed pumped storage unit self-starting simulation. The method simplifies the calculation of motor iron loss and builds an accurate AC excitation motor model to achieve simulation test of self-starting performance under different starting control parameters.

[0098] Furthermore, the present embodiment also provides a multi-resource inertia and primary frequency regulation auxiliary service sequence acquisition system, including a data acquisition module, an iron loss conversion module, a motor model building module, and a self-starting simulation test module;

[0099] The data acquisition module is used to obtain relevant electrical status data of the variable speed pumped storage unit, including electrical parameters of the variable speed pumped storage unit, such as rated power, rated capacity, rated voltage, rated current, rated excitation current, rated frequency, number of magnetic pole pairs, direct axis inductance, quadrature axis inductance, excitation winding self-inductance, stator winding and excitation winding mutual inductance, stator resistance, excitation winding resistance;

[0100] The iron loss conversion module is used to simplify the calculation of the motor iron loss by converting the impedance parameter (Z parameter), and approximate the excitation branch by multiplying the conversion factor modulus value to obtain the final simplified equivalent parameter;

[0101] The motor model building module is used to build an AC excitation motor model of a variable speed pumped storage unit to obtain a final simplified model;

[0102] The self-starting simulation test module is used to simulate and test the self-starting performance of the variable speed pumped storage unit under different starting control parameters, including the electrical connection of the motor, excitation control and the configuration of the frequency converter, and to test different starting parameters.

[0103] This embodiment also provides a computer device, which is suitable for a self-starting simulation test method based on the converted iron loss of a variable speed pumped storage unit, and includes a memory and a processor; the memory is used to store computer executable instructions, and the processor is used to execute computer executable instructions to implement the self-starting simulation test method based on the converted iron loss of a variable speed pumped storage unit as proposed in the above embodiment.

[0104] The computer device may be a terminal, and the computer device includes a processor, a memory, a communication interface, a display screen and an input device connected via a system bus. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be achieved through WIFI, an operator network, NFC (near field communication) or other technologies. The display screen of the computer device may be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device may be a touch layer covering the display screen, or a key, trackball or touchpad provided on the housing of the computer device, or an external keyboard, touchpad or mouse, etc.

[0105] This embodiment also provides a storage medium on which a computer program is stored. When the program is executed by a processor, the self-starting simulation test method based on the converted iron loss of the variable-speed pumped storage unit as proposed in the above embodiment is implemented.

[0106] In summary, the present invention applies the Z parameter conversion method to the simplified calculation of the iron loss of the variable speed pumped storage unit, and combines it with an accurate AC excitation motor model to achieve efficient simulation of the self-starting performance of the unit. In particular, the segmented setting of control parameters can better adapt to the dynamic changes during the motor starting process, and has significant practical value. This method can provide theoretical guidance for the design and operation of variable speed pumped storage units, and help improve the operating efficiency and reliability of the units.

[0107] Example 2

[0108] Reference Figure 1-Figure 7 , which is the second embodiment of the present invention, and this embodiment provides a self-starting simulation test method based on converting the iron loss of a variable-speed pumped storage unit. This embodiment aims to demonstrate the innovation and advantages of the present invention by comparing the performance of the traditional method and the method of the present invention in the self-starting simulation test.

[0109] In this embodiment, we first built a simulation environment for a variable speed pumped storage unit. This environment simulates an actual variable speed pumped storage unit, including a doubly fed generator and a pump turbine. We collected the electrical parameters of the unit, including rated power, rated capacity, rated voltage, etc., and used these data to build an accurate motor model. In order to simulate the motor iron loss, we used the impedance parameter (Z parameter) conversion method to adjust the iron loss resistance and excitation reactance through the conversion factor, thereby simplifying the calculation of iron loss.

[0110] In the simulation environment, we simulated the self-starting performance of the motor under different starting control parameters. We set four groups of starting parameters, including reducing the control parameters to 0.7 times, keeping them unchanged, increasing them to 2 times, and setting the control parameters in stages according to the motor speed. Each group of parameters was simulated multiple times to ensure the reliability of the results.

[0111] During the simulation, we paid special attention to key performance indicators such as the motor's starting time, starting current, and energy consumption, as shown in Table 1. We recorded these data and compared them with the simulation results of the traditional fixed-speed pumped storage unit. Through comparative analysis, we found that the method of the present invention has significant improvements in both starting time and energy consumption.

[0112] Table 1

[0113]

[0114] By comparing the data in the table, we can clearly see the beneficial effects of the present invention. First, in terms of starting time, the starting time of the variable speed pumped storage unit of the present invention is reduced by 15 seconds compared with the traditional fixed speed unit, which is a significant improvement. This shows that the self-starting simulation test method of the present invention can make the unit reach the working state faster and improve the starting efficiency.

[0115] Secondly, in terms of starting current, the starting current of the variable speed pumped storage unit is 500A lower than that of the traditional unit. This means that during the starting process, the motor of the variable speed pumped storage unit is subjected to less electric force, thereby reducing the wear and maintenance cost of the motor.

[0116] Finally, in terms of energy consumption, the energy consumption of the variable speed pumped storage unit is 1.4 kWh lower than that of the traditional unit. This shows that the self-starting simulation test method of the present invention also has obvious advantages in energy saving, which helps to reduce operating costs and improve economic benefits.

[0117] In summary, the present invention has the following creative and novel effects in comparison with the shortcomings of the prior art in the embodiments: improved starting efficiency, reduced motor wear, and reduced energy consumption. These improvements not only improve the performance of the variable speed pumped storage unit, but also help reduce long-term operating costs, and have important practical value and market competitiveness.

[0118] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A self-starting simulation test method based on the conversion of iron loss of variable speed pumped storage units, characterized in that: include, Obtain relevant electrical status data of variable speed pumped storage units; The motor iron loss is simplified by converting the impedance parameter (Z parameter). Build a variable speed pumped storage unit AC excitation motor model; The self-starting performance of variable-speed pumped storage units under different starting control parameters is simulated and tested.

2. The self-starting simulation test method based on the conversion of the iron loss of the variable speed pumped storage unit according to claim 1 is characterized in that: The acquisition of the electrical status data related to the variable-speed pumped-storage unit includes electrical parameters of the variable-speed pumped-storage unit, such as rated power, rated capacity, rated voltage, rated current, rated excitation current, rated frequency, number of pole pairs, direct-axis inductance, quadrature-axis inductance, self-inductance of the excitation winding, mutual inductance of the stator winding and the excitation winding, stator resistance, and excitation winding resistance.

3. The self-starting simulation test method based on the conversion of the iron loss of the variable speed pumped storage unit according to claim 2 is characterized in that: The motor iron loss is simplified by converting the impedance parameter (Z parameter), which is expressed as Let the transformation factor be: Where Δ is the transformation factor, R Fe is the iron loss resistance, j is the imaginary unit, X m is the magnetizing reactance before transformation; The excitation branch is approximated by multiplying the modulus of the transformation factor, and the final equivalent parameters are: Among them, Z final is the parameter matrix of the final simplified equivalent model, z1 and z2 are the transition parameters of the transition equivalent model respectively.

4. The self-starting simulation test method based on the conversion of the iron loss of the variable speed pumped storage unit according to claim 3 is characterized in that: The variable speed pumped storage unit AC excitation motor model is expressed as make Δz1=R s +jX s Δz2=R r +jX r jX m |Δ|=jωL m Among them, z1 and z2 are transition parameters of the transition equivalent model, R s , R r are the stator resistance and rotor resistance of the final simplified equivalent model, X s , X r are the stator reactance and rotor reactance of the final simplified equivalent model, ω is the grid frequency, L m is the magnetizing inductance; The final simplified model is obtained.

5. The self-starting simulation test method based on the conversion of the iron loss of the variable speed pumped storage unit according to claim 4 is characterized in that: The simulation and test of the self-starting performance of the variable speed pumped storage unit under different starting control parameters includes the electrical connection of the motor, the excitation control and the configuration of the frequency converter.

6. The self-starting simulation test method based on the conversion of the iron loss of the variable speed pumped storage unit according to claim 5 is characterized in that: The electrical connection of the motor includes connecting the grid to the stator winding of the doubly-fed motor through a step-down transformer; The other side passes through the excitation transformer and is connected to the rotor winding of the motor through a three-level converter with an AC-DC-AC structure; A DC voltage source is connected in parallel to each capacitor of the upper and lower half bridges on the DC side of the converter.

7. The self-starting simulation test method based on the conversion of the iron loss of the variable speed pumped storage unit according to claim 6 is characterized in that: The excitation control and inverter configuration include considering the resistance torque during the motor starting process, raising the DC side voltage of the inverter to 1.3 times the normal operating voltage during the self-starting stage, and controlling the motor to self-start from a stationary state through the AC excitation system. Four groups of starting parameters are tested, namely, reducing the control parameter to 0.7 times, keeping the control parameter unchanged, increasing the control parameter to 2 times, and setting the control parameter in sections according to the motor speed.

8. A system using the self-starting simulation test method based on the conversion of the iron loss of a variable speed pumped storage unit as claimed in any one of claims 1 to 7, characterized in that: Including data acquisition module, iron loss calculation module, motor model building module, self-starting simulation test module; The data acquisition module is used to obtain relevant electrical status data of the variable speed pumped storage unit, including electrical parameters of the variable speed pumped storage unit, such as rated power, rated capacity, rated voltage, rated current, rated excitation current, rated frequency, number of magnetic pole pairs, direct axis inductance, quadrature axis inductance, excitation winding self-inductance, stator winding and excitation winding mutual inductance, stator resistance, excitation winding resistance; The iron loss conversion module is used to simplify the calculation of the motor iron loss by converting the impedance parameter (Z parameter), and approximate the excitation branch by multiplying the conversion factor modulus value to obtain the final simplified equivalent parameter; The motor model building module is used to build an AC excitation motor model of a variable speed pumped storage unit to obtain a final simplified model; The self-starting simulation test module is used to simulate and test the self-starting performance of the variable speed pumped storage unit under different starting control parameters, including the electrical connection of the motor, excitation control and the configuration of the frequency converter, and to test different starting parameters.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the self-starting simulation test method based on converting the iron loss of the variable speed pumped storage unit according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the self-starting simulation test method based on converting the iron loss of a variable-speed pumped storage unit according to any one of claims 1 to 7 are implemented.

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