JP2014199500A - Advance simulation method and advance simulation program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an advance simulation method and an advance simulation program which allow the optimum advance value to be obtained in three-dimensional magnetic field analysis for obtaining the efficiency of a motor on a computer.SOLUTION: An advance value and motor efficiency are computed on the basis of a converged position detection error obtained by: an input step of inputting required parameters; a three-dimensional magnetic field analysis processing step of performing three-dimensional magnetic field analysis processing on a computer on the basis of respective input parameters to obtain at least a magnetic flux density as a three-dimensional magnetic field analysis processing result; a position detection error computation step of computing a position detection error due to an influence of a magnetic flux density from a stator, of a position detection signal of a rotor based on a magnetic flux density of a magnet to be detected by position detection means, on the basis of the magnetic flux density of the magnet to be detected by position detection means; and a convergence determination step of determining whether the position detection error is converged or not by adding the position detection error to the advance value to repeat the three-dimensional magnetic field analysis processing step and the position detection error computation step.

Description

  The present invention relates to an advance angle simulation method for determining an optimum voltage advance angle in the design of a fan motor for an air conditioner.

  Air conditioner fan motors are required to be compact and highly efficient, so they have been designed with various ingenuity. At that time, in addition to the physical structure of the rotor (rotor), stator (stator), etc., the optimal voltage that maximizes the motor efficiency at each of the multiple load points, as well as the position of the Hall element for detecting the rotor position There are many parameters that must be determined for improving the performance of the motor, such as the advance value of the advance angle (a parameter that controls the timing of energization of the stator winding (armature coil)).

  As a technique for efficiently performing these designs, there is a simulation using a three-dimensional magnetic field analysis model. As shown in FIG. 7, the three-dimensional magnetic field analysis model is a three-dimensional representation of the structure of the motor rotor, stator, etc. The magnetic field change can be simulated on a computer. As a result, the efficiency of the motor can be calculated on the computer.

  Thus, in order to improve motor performance at the design stage, magnetic field analysis and circuit analysis in each circuit design of the magnetic circuit that determines the flow of magnetic flux between the stator and the rotor and the drive circuit that controls the drive of the motor. The use of simulation is becoming indispensable. The air conditioner fan has a load characteristic in which the torque increases with the rotation speed, and there is an optimum voltage advance angle at which the motor efficiency is maximized at each of the plurality of load points. Therefore, the voltage advance angle is important in determining the motor performance. It is a parameter.

  In order to drive the motor so as to maximize the motor efficiency, it is necessary to accurately detect the rotational position of the rotor by the Hall element and to energize the armature coil with an appropriate voltage advance angle by the drive circuit. However, since the Hall element detects not only the magnetic flux of the rotor but also the magnetic flux generated by the armature coil, an error occurs in the position signal, and the current cannot be energized at an appropriate voltage advance, causing a reduction in efficiency. . Therefore, it is necessary to consider the influence of the magnetic circuit in the drive circuit design. However, since the output voltage of the Hall element is as small as several tens of mV, it is difficult to perform highly accurate measurement that determines the influence of the magnetic circuit. Furthermore, measurement of this phenomenon is difficult because the measurement system affects the output voltage and the position detection becomes abnormal and the motor itself is abnormal.

In Patent Document 1, in view of the problem that the Hall element is adversely affected by the magnetic flux from the armature coil, a shield is interposed between the position sensor and the coil so that the magnetic flux from the coil to the position sensor is caused by the shield. A permanent magnet type motor that is shielded and prevents the position sensor from malfunctioning due to the influence of magnetic flux from the coil is disclosed.
JP 2002-153039 A

  According to the configuration of Patent Document 1, the accuracy of detecting the rotor position by the Hall element is improved, but there is a problem in that restrictions on the structure of the motor are added. Ideally, an optimum advance angle can be set in consideration of the rotor position detection error without adopting a special structure.

Incidentally, FIG. 17 is a flowchart showing a flow in the case of simulating the efficiency of the motor by the conventional three-dimensional magnetic field analysis processing. It is assumed that there is already a three-dimensional magnetic field analysis model in which parameters for determining structural characteristics of the motor have been input. For example, stator winding resistances R _u , R _v , R _w [Ω] are already input parameters. In this three-dimensional magnetic field analysis model, first, the motor rotational speed N _t [rpm], the target torque T _t [Nm], and the advance value δ [deg] for which efficiency is to be obtained are input (S2201). Then, the n = 1 (S2202), 3-dimensional magnetic field analysis of the performed by the rotation speed _{N t,} advance value [delta], obtaining a result torque _T n [Nm] obtained in the conditions of the supply voltage _{V mn} (S2203). Then, the target torque T _t and the resultant torque T _n are compared (S2204). If the comparison results are far from each other, the power supply voltage V _mn is adjusted (adjusted to decrease the voltage if the resultant torque is larger than the target torque and increase the voltage if the resultant torque is smaller) (S2205), and n = n + 1 (S2206). ) A three-dimensional magnetic field analysis is again performed using the adjusted power supply voltage V _mn to obtain a result torque T _n [Nm] (S2203). By repeating this process, the result torque T _n and the power supply voltage V _mn are obtained when the target torque T _t and the result torque T _n substantially coincide (below a predetermined threshold).

From the results obtained torque T _n and the supply voltage V _mn calculates the motor efficiency.
Motor efficiency = output / input x 100 [%]
Output = machine output = 2πN _t / 60 · T _n [W]
Input = input power [W]
Input power ≒ Machine output + Copper loss + Iron loss [W]
Copper loss ^{_{= R u · I u 2 +}} R v · I v 2 + R w · I w 2

  As described above, motor efficiency in magnetic field analysis can be obtained by using the three-dimensional magnetic field analysis model. Then, the advance value of the voltage advance angle input as a parameter in the magnetic field analysis is changed for each magnetic field analysis, and the motor efficiency at each advance angle value is calculated and compared to maximize the motor efficiency. Since the voltage advance angle (optimum advance angle value) can be obtained, it helps to improve the motor design efficiency.

  However, in the three-dimensional magnetic field analysis, it is known that the optimum advance value obtained by the magnetic field analysis is different from the optimum advance value obtained experimentally with the actually manufactured motor. The problem was that it took time to determine the optimum advance value because the actual machine was manufactured for each advance value candidate and the efficiency evaluation test was performed and the optimum advance value was determined as the optimum advance value. was there. The inventor of the present invention believes that the difference between the optimum advance value in the magnetic field analysis and the optimum advance value obtained by the prototype motor is a position detection error due to the influence of the magnetic flux from the stator on the position detecting means such as the Hall element. I found out.

  The present invention has been made in view of the above problems, and proposes a three-dimensional magnetic circuit coupled analysis method for obtaining the magnetic flux density detected by the Hall element by simulation and correcting the advance value of the voltage advance angle. An object of the present invention is to provide an advance value simulation method and an advance value simulation program capable of obtaining an angle value.

  Claim 1 of the present invention comprises a stator around which a winding is wound, a rotor having a magnet, and position detecting means for detecting the position of the rotor by measuring the magnetic flux density of the magnet. With respect to the motor, a control parameter including an advance value for controlling energization timing to the stator winding, a shape parameter specifying the shape of the motor, a magnetic characteristic parameter including a magnetic flux density of the magnet, and the rotation A simulation method for simulating magnetic flux density and motor efficiency by inputting a motor operating state parameter including the number of rotations of a child and performing a three-dimensional magnetic field analysis process by a computer, and an input procedure for inputting the parameters And the computer performs the three-dimensional magnetic field analysis process based on the input parameters, and the three-dimensional magnetic field analysis process result Based on the three-dimensional magnetic field analysis processing procedure for obtaining the magnetic flux density to be detected by at least the position detecting means and the magnetic flux density to be detected by the position detecting means, the magnet to be detected by the position detecting means A position detection error calculation procedure for calculating a position detection error due to the influence of magnetic flux from the stator of the rotor position detection signal based on the magnetic flux density, and adding the position detection error to the advance value, the 3 The convergence position detection error obtained by repeating the dimensional magnetic field analysis processing procedure and the position detection error calculation procedure to determine whether or not the position detection error converges is added to the advance value. An advance angle simulation method that simulates motor efficiency based on an angle value and a lead angle value.

  According to a second aspect of the present invention, there is provided a stator around which a winding is wound, a rotor having a magnet, and position detecting means for detecting the position of the rotor by measuring the magnetic flux density of the magnet. With respect to the motor, a control parameter including an advance value for controlling energization timing to the stator winding, a shape parameter specifying the shape of the motor, a magnetic characteristic parameter including a magnetic flux density of the magnet, and the rotation A simulation program for simulating magnetic flux density and motor efficiency as a result of a three-dimensional magnetic field analysis process by inputting a motor operating state parameter including the number of rotations of a child and performing a three-dimensional magnetic field analysis process with a computer, In the computer provided with the memory, the external storage device, and the input device, each of the parameters input by the input device. An input procedure for recording a meter in an external storage device, and the CPU performs the three-dimensional magnetic field analysis processing based on the input parameters, and at least the position detection means should detect the result of the three-dimensional magnetic field analysis processing Based on the three-dimensional magnetic field analysis processing procedure for obtaining and storing the magnetic flux density in the memory and the magnetic flux density to be detected by the position detecting means, the magnetic flux density from the rotor to be detected by the position detecting means A position detection error calculation procedure in which a position detection error due to the influence of magnetic flux from the stator of the rotor position detection signal based on the CPU is calculated and stored in the memory, and the position detection error is converted into the advance value. In addition to the above three-dimensional magnetic field analysis processing procedure and the position detection error calculation procedure, the CPU determines whether or not the position detection error converges. The converged position detection error obtained by the constant procedure is added to the advance value, and the advance value obtained by calculation by the CPU and the motor efficiency based on the advance value are stored in the memory as simulation results. This is an advance angle simulation program characterized by the above.

  According to the present invention, a corrected advance angle value is obtained by adding a position detection error caused by magnetic flux generated by energizing the stator winding. Therefore, since the optimum advance value of the actual motor can be simulated, the man-hour for manufacturing the actual machine for each advance value candidate can be greatly reduced.

It is a schematic diagram showing the schematic shape of the analysis object machine. It is a circuit diagram showing the drive circuit of the analysis object machine. It is a graph showing the fan load characteristic and the efficiency of a load point of an analysis object machine. It is the schematic showing the mode of the magnetic flux line around a Hall element. It is the flowchart which showed the flow of the position detection in the drive circuit of an object machine. It is explanatory drawing showing the principle which a position detection error produces in the drive circuit of an object machine. It is a schematic diagram showing an example of a three-dimensional magnetic field analysis model. It is a time chart showing the on-off timing of the U-phase induced voltage V _u and the switching elements T _u1 and T _u2 . It is a flowchart showing the flow of the advance angle simulation process by this invention. It is a block diagram showing the measurement system for evaluating an experimental machine. It is the schematic diagram showing Hall element arrangement | positioning, (a) is (theta) _h = 0 degree and (b) is (theta) _h = 60 degree. It is a wave form diagram showing the analysis result and measurement result of a no-load induced voltage. It is a wave form diagram showing the magnetic flux density analysis result in case Hall element arrangement | positioning is (theta) _h = 0 degree. It is a wave form diagram showing the Hall element output voltage waveform converted from magnetic flux density _BHz of FIG. It is a wave form diagram showing a phase current waveform. It is a block diagram showing the hardware constitutions for performing advance angle simulation by the present invention. It is the flowchart which showed the flow in the case of simulating the efficiency of a motor by the conventional three-dimensional magnetic field analysis process.

  The advance angle simulation method according to the present invention includes a stator around which a winding is wound, a rotor having a magnet, and position detecting means for detecting the position of the rotor by measuring the magnetic flux density of the magnet. With respect to the motor provided, for example, parameters as shown in Table 1, that is, a control parameter including an advance value for controlling the energization timing to the stator winding, a shape parameter for specifying the shape of the motor, By inputting a magnetic characteristic parameter including the magnetic flux density of the magnet and an operating state parameter of the motor including the rotation speed of the rotor and performing a three-dimensional magnetic field analysis process by a computer, a magnetic flux is obtained as a result of the three-dimensional magnetic field analysis process. A simulation method capable of simulating density and motor efficiency, wherein an input procedure for inputting each parameter and an input A three-dimensional magnetic field analysis processing procedure for performing the three-dimensional magnetic field analysis processing by a computer based on each parameter and obtaining at least the magnetic flux density to be detected by the position detection means as a result of the three-dimensional magnetic field analysis processing; Based on the magnetic flux density to be detected by the detecting means, the position detection by the influence of the magnetic flux density from the stator of the rotor position detection signal based on the magnetic flux density of the magnet to be detected by the position detecting means. Whether the position detection error converges by repeating the position detection error calculation procedure for calculating the error and the three-dimensional magnetic field analysis processing procedure and the position detection error calculation procedure by adding the position detection error to the advance value. And the convergence efficiency detection procedure obtained by adding the converged position detection error to the advance value and the motor efficiency based on the advance value. It is characterized in that Shon. Details will be described below.

  In this embodiment, a three-dimensional magnetic circuit coupled analysis method for finding the magnetic flux density detected by the Hall element by simulation and correcting the advance value of the drive circuit is proposed, and the analysis result and the experimental result are compared. The specifications of the target machine shown below are conditions that are commonly adopted by both the actual machine and the three-dimensional model.

1. Target machine specifications and problems of conventional magnetic field analysis [Target machine specifications]
Table 1 shows the specifications of the machine to be analyzed, FIG. 1 shows the schematic shape of the machine to be analyzed, and FIG. 2 shows the drive circuit configuration.

This machine is a brushless DC motor (SPM motor) for driving an air conditioner indoor unit fan. The stator (stator) is a 12-slot concentrated winding and is sealed with a thermosetting resin. A ferrite sintered magnet is used for the rotor (rotor), and the shape of the magnet has an overhang longer in the axial direction than the stator core. For example, a 150 ° energization PWM inverter is used to drive the motor. The Hall elements H _U , H _V , and H _W are arranged on the teeth center line of the stator and separated from the magnet end by L _{h in the} Z direction, and the magnetic flux density of the rotor magnet is detected and input to the controller as rotational position information. The controller switches the switching elements (MOSFETs) T _U1 , T _U2 , T _V1 , T _V2 , T _W1 , T _W2 based on the rotor position information and the advance value. This machine has an advance value (optimum advance value) of 17 ° that minimizes input (maximum motor efficiency) at medium load (rotation speed 1160 rpm). On the other hand, as will be described below, the optimum advance value by magnetic field analysis not considering the position detection error is 5 °, which is different from the optimum advance value of this machine. Therefore, if the advance value obtained by the magnetic field analysis without considering the position detection error is used as it is, the motor efficiency of the actual motor is lowered. The reason why the optimum advance value differs is that the following error is not taken into account in the conventional magnetic field analysis.
(A) Error due to Hall element detection sensitivity (b) Error due to armature magnetic flux superposition

[Load characteristics of target machine]
FIG. 3 shows fan load characteristics and load point efficiency of the target machine. The motor efficiency is a magnetic field analysis result when the above-mentioned error is not considered in the optimum advance value. FIG. 3 (a) shows the torque-rotational speed characteristics: Low (low load (0.018Nm, 480rpm)), Middle (medium load (0.177Nm, 1160rpm)), High (high load (0.384Nm, 1580rpm). The load torque increases in the order of)). FIG. 3B shows the efficiency-advance characteristics for each load point, and δ _Optimal represents the advance value at which the motor efficiency is maximized. As the load torque increases, the phase of the optimum advance angle (0 ° (low load), 5 ° (medium load), 15 ° (high load)) tends to advance.

[Hall element detection error factors in the target machine]
FIG. 4 shows a schematic diagram of magnetic flux lines around the Hall element. The Hall element detects the Z component B _Hz of the magnetic flux density B _H and outputs a voltage signal V _B proportional to the constant K _H [mV / mT] as shown in the following equation (1).
V _B = K _H · B _Hz (1)
Because the B _H are mainly affects the magnetic flux density B _a generated by the energization of the magnetic flux density B _m according magnet stator windings, an error in position detection by the Hall element and the magnetic flux density B _a increases impact It becomes a factor to occur.

FIG. 5 shows a position detection flow in the drive circuit. Hall element detects the Z component B _Hz of the magnetic flux density B _H including the influence of the magnetic flux density B _a generated by the energization of the magnetic flux density B _m and the stator windings, and outputs to the controller as a voltage signal V _B ( S501). The controller converts V _B into a position signal via a hysteresis circuit (± V _H ) for preventing malfunction due to noise (S502), and sets the energization width (S503) and the advance value δ (S504). The output signal of the driver (PWM inverter transistor) is output. As the switching signal is energized windings from the driver motor is driven (S505), the magnetic flux density B _a generated by being energized windings affects the magnetic flux density B _H (S506).

The principle that a position detection error occurs in the drive circuit is shown in FIG. FIG 6 is a waveform due to the electrical angle of the V _B schematically. It is assumed that when θ = 0 °, the gap between the magnets passes in front of the Hall element and the polarity is switched from S to N. The time required for the Hall element to convert the magnetic flux density into a voltage is several ns, and the detection delay is ignored because it is very small for about 10 ms of one electrical angle cycle. A waveform when no load is applied to the stator winding is V _B0 , and a waveform when a load is applied is V _BL . Via the hysteresis circuit of the threshold value ± V _H , if there is no load with respect to the actual magnetic pole position inside the controller (when only the motor rotor is rotated at the rotational speed N _t without energizing the coil), Δθ ₀ , In the case of a load, an error of Δθ _L occurs. This error is added to the originally commanded advance angle value δ (actual command advance angle value δ), and is actually driven at the advance angle value δ ′ (actual drive advance angle value δ ′). In the SPM motor described above, in the case of a medium load, the actually commanded optimum advance angle (corresponding to the actual command advance value δ) is 17 °, but the optimum advance angle (actual drive advance value when no error is taken into consideration). It can be seen that (corresponding to δ ′) is 5 °, and Δθ _L is 12 °. Therefore, in the following, with reference to three-dimensional magnetic field analysis process, in consideration of an error of Δθ actually against advance for commanding (actual command advance value [delta]) _L, actually driven advance value (actual A method of advance angle simulation for obtaining the drive advance value δ ′) is proposed.

2. Details of advance angle simulation [Hardware configuration]
FIG. 16 shows a hardware configuration for performing advance angle simulation. The computer includes a CPU, a memory, and a hard disk drive (HDD) as an external storage device, a mouse and keyboard as input devices, and a display as a display device. The hard disk drive stores software and input / output data for performing advance angle simulation.

[Analysis model]
FIG. 7 shows a three-dimensional magnetic field analysis model. This three-dimensional magnetic field analysis model reproduces the structure of the target machine with a mesh. In the machine to be analyzed, the rotor magnet has an overhang and leakage flux is generated in the air. Furthermore, a three-dimensional analysis is necessary to calculate the magnetic flux density detected by the Hall element.

In performing the three-dimensional magnetic field analysis, the switching element of the drive circuit in FIG. 2 is approximated by a variable resistor. In the case of ON (conducting), the resistance value of the MOSFET is 4Ω, and in the case of OFF (non-conducting), the resistance value is set to 1 MΩ as a value at which the current flowing through the switching element can be ignored. FIG. 8 shows a time chart of the U-phase induced voltage V _u and the switching elements T _u1 and T _u2 . A case where 150 ° energization is performed around the maximum value of the phase induced voltage is δ = 0 °.

[Advance angle simulation method according to the present invention]
FIG. 9 is a flowchart showing the flow of the advance angle simulation of the present invention. As a precondition for advance angle simulation, control parameters including an advance angle value that controls the timing of energizing the stator winding, shape parameters that specify the shape of the motor, magnetic characteristic parameters including the magnetic flux density of the magnet, and rotor speed It is assumed that there is already a 3D magnetic field analysis model in which parameters for determining the structural characteristics of the motor, such as motor operating state parameters including, are recorded in the hard disk drive in advance, which is based on 3D magnetic field analysis software Has been created. For example, stator winding resistances R _u , R _v , R _w [Ω] are already input parameters. On the premise that this three-dimensional magnetic field analysis model is constructed, in the following, in the case of “three-dimensional magnetic field analysis processing”, the three-dimensional magnetic field analysis software stored in the HDD is read on the computer of FIG. It means processing that performs arithmetic processing by the CPU and appropriately stores the arithmetic result in the memory. In other arithmetic processes, it goes without saying that the arithmetic expression is read from the memory, the arithmetic process is performed, and the calculation result is stored in the memory.

First, the parameter input procedure will be described. In this procedure, the motor speed N _t [rpm], the target torque T _t [Nm], and the actual command advance value δ [deg] of the motor whose efficiency is to be obtained are input using an input device such as a keyboard. This is stored in the memory (S901). Here, the actual command advance angle value δ to be input is, for example, what seems to be optimal based on the experience of engineers. Next, it determined by the position detection error [Delta] [theta] ₀ of the three-dimensional magnetic field analysis in a case (the case of no load) where only the motor rotor does not energize the coil was rotated at a rotational speed N _t (S902). The position detection error Δθ ₀ is obtained by calculation using the equation (1) based on the Z component B _Hz of the magnetic flux density B _H obtained by the three-dimensional magnetic field analysis process. Then, a variable k = 1 related to the advance value δ is set (S903), and δ _k = δ−Δθ ₀ is defined (S904). The initial advance value δ ₁ is a value obtained by adding the no-load error Δθ ₀ to the actual command advance value δ input in (S901). Since the input of the position detection error Δθ ₀ at no load is a procedure performed for shortening the calculation time of the final advance simulation and is not an indispensable procedure, the advance angle input in the above (S901). By using δ ₁ = δ using the value, the steps (S902) and (S903) may be omitted, and the process may proceed to the next (S905).

Next, a three-dimensional magnetic field analysis processing procedure will be described. In this procedure, first, a variable related to the power supply voltage is set to n = 1 (S905). Next, a three-dimensional magnetic field analysis process is performed to obtain a resultant torque T _n [Nm] obtained under the conditions of the rotational speed N _t , the advance value δ _k , and the power supply voltage V _mn (S906). Then, the target torque T _t stored in the memory is compared with the obtained result torque T _n (S907). When the comparison results are far from each other, the power supply voltage V _mn is adjusted (S908). Here, the adjustment of the power supply voltage V _mn means that the voltage is reduced if the resultant torque is larger than the target torque, and that the increased voltage is overwritten in the memory if the resultant torque is smaller. Then, n = n + 1 is set (S909), a three-dimensional magnetic field analysis process is performed again with the adjusted power supply voltage _Vmn , and a result torque _Tn is obtained and stored in the memory (S906). By repeating this processing, when the target torque T _t and the result torque T _n substantially coincide (below a predetermined threshold), the result torque T _n , the power supply voltage V _mn , and the stator winding current value I _u , I _v , I _w (3 phase), Hall element magnetic flux density Z component B _{Hz and the} like are obtained and stored in the memory (S907).

Next, the position detection error calculation procedure will be described. In this procedure, first, the position detection error Δθ _Lk is obtained by calculation based on the Hall element magnetic flux density Z component B _Hz obtained in the three-dimensional magnetic field analysis processing procedure (S910). For example, as shown in FIG. 14, the position detection error Δθ _Lk includes the output voltage of the Hall element when there is no load from the zero-cross point of the output voltage of the Hall element when there is no load, and the threshold value (−V _H ) of the hysteresis circuit. Obtained from the angle to the intersection of The kth position detection error Δθ _Lk obtained here is compared with the previous k−1th position detection error Δθ _Lk−1 (S911). If the two values are separated (become a predetermined threshold value or more), the variable is set to k = k + 1 (S912), and the data on the memory is overwritten as δ _k = δ−Δθ _Lk−1 (S913). Then, the processing based on the new advance value _{δ k (S905) ~ (S911} ), the position detection error [Delta] [theta] _Lk and previous k-1-th position detection error [Delta] [theta] _Lk-1 substantially coincide (predetermined threshold to below as made), the process is repeated while modifying the [delta] _k in (S912) and (S913).

Next, the convergence determination procedure will be described. In this procedure, first, it is determined that the position detection error has converged when Δθ _Lk ≈Δθ _Lk−1 (S911). As a result of convergence, as a final calculation result, a position detection error Δθ _L and an actual drive advance value δ ′ taking this position detection error Δθ _L into consideration are calculated by the following equation and stored in the memory ( S914).
Δθ _L = Δθ _Lk−1 (2)
δ ′ = δ−Δθ _L (3)
By the above processing, the final actual drive advance value δ ′ is obtained as the advance angle simulation. Along with this final actual drive advance value δ ′, the resulting torque T _n , power supply voltage V _mn , stator winding current values I _u , I _v , I _w (three phases), Hall element magnetic flux density The result such as the Z component B _Hz is recorded in the HDD as output data.

ここで、η：モータ効率［％］、Ｐ_ｏ：モータ出力［Ｗ］、Ｐ_ｉ：モータ入力［Ｗ］、Ｗ_ｃ：銅損［Ｗ］、Ｗ_ｉ：ステータコア鉄損［Ｗ］、Ｎ：回転数［ｒｐｍ］、Ｔ：トルク［Ｎｍ］である。
ステータコア鉄損Ｗ_ｉは高調波を含む損失算定法を用いた。ここではステータコア鉄損を算出する際のヒステリシス損係数Ｋ_ｈと渦電流損係数Ｋ_ｅは二周波法で求め、Ｋ_ｈ＝２．４２×１０^−２［Ｗ／ｋｇ／Ｈｚ／Ｔ^２］、Ｋｅ＝１．７４×１０^−４［Ｗ／ｋｇ／Ｈｚ／Ｔ^２］とした。なお、インバータ損や機械損、風損、その他損失は考慮していない。 [Motor efficiency calculation]
Moreover, based on the obtained output data, motor efficiency is calculated | required by following Formula.

Here, eta: motor efficiency [%], _{P o:} Motor Output [W], _{P i:} the motor input _[W], W _c: copper loss _[W], W _i: stator core iron loss [W], N: Rotational speed [rpm], T: Torque [Nm].
The stator core iron loss W _i used the loss calculation methods including harmonics. Here, the hysteresis loss coefficient K _h and the eddy current loss coefficient K _e when calculating the stator core iron loss are obtained by the two-frequency method, and K _h = 2.42 × 10 ⁻² [W / kg / Hz / T ² ], Ke = 1.74 × 10 ⁻⁴ [W / kg / Hz / T ² ]. Note that inverter loss, mechanical loss, windage loss, and other losses are not considered.

3. Experimental method for validity evaluation of lead angle simulation [Measurement system]
In order to evaluate the validity of the advance angle simulation, it is necessary to perform an evaluation by comparing with a value measured by a prototype motor (hereinafter, “experimental machine”). FIG. 10 shows a measurement system. In FIG. 10, the speed command voltage V _SP is adjusted, the SPM motor is driven at a predetermined rotational speed and torque, the motor input P _i , current and voltage are measured with a power meter, and the torque T is measured with a torque meter. Measure and record these results in the HDD of the computer. Loss other than the copper loss as iron loss and other losses W _etc, obtained by the following equation.
_{W etc = P i -P o -W} c ··· (7)

FIG. 11 shows the Hall element arrangement. The Hall element arrangement θ _h is represented by an electrical angle. The Type I motor, which is an experimental machine, has a Hall element arrangement of θ _h = 0 ° shown in FIG. 11A and a fixed advance angle of an actual command advance angle value δ = 17 °. This Type I motor is used to evaluate the detection error of the Hall element when the advance angle is fixed.

4). Evaluation of experiment and analysis results [No-load induced voltage]
Compare the no-load induced voltage and confirm the magnetic flux analysis accuracy. FIG. 12 shows analysis results and measurement results. The waveforms match well and are accurate enough.

[Hall element detection error]
The analysis of the detected error in the Hall element H _w. FIG. 13 shows the magnetic flux density analysis results. Each waveform represents the Z direction component of the magnetic flux density of the Hall element. (A) B _mz is only magnet magnetic flux, (b) B _Hz is under load (1580 rpm, 0.384 Nm), (c) B _az is only armature coil under load, (d) B _mz + B _az is magnet magnetic flux And an armature coil. The waveform of only the B _az armature coil is a result obtained by taking out a current waveform at the time of loading and inputting and calculating as a coil current of an analysis model in which the magnet portion is replaced with air. When attention is paid to the vicinity of electrical angles of 90 ° and 270 °, the phase of B _Hz is delayed with _respect to B _mz . B _Hz substantially matches the waveform obtained by adding B _mz and B _az, and it can be seen that the phase is delayed by the magnetic flux of the armature coil.

FIG. 14 shows the Hall element output voltage waveform converted from the magnetic flux density B _Hz in FIG. Here, K _H = 1.604 [mV / mT] and V _H = 10.5 [mV] based on characteristics of the Hall element and the controller. As a result, Δθ ₀ = 7.6 °, Δθ _L = 16.8 °, and an error of Δθ _L is added to the Hall element of the motor of TYPE 1 with the actual command advance value δ = 17 ° at the time of load. The actual drive advance value δ ′ = 0.2 °.

  FIG. 15 shows the phase current waveform. With respect to the waveform measured by the experimental machine, the analysis result when the actual drive advance angle value is 17 ° without considering the error as in the conventional case is shifted. On the other hand, the analysis waveform based on the actual drive advance value δ ′ = 0.2 ° obtained in the advance angle simulation according to the present invention is in good agreement with the waveform measured by the experimental machine. When the effective values are compared, the experimental machine (0.390 A), the actual drive advance value = 17 ° (0.360 A), and the actual drive advance value = 0.2 ° (0.387 A) are obtained. The result of analysis using the actual drive advance value δ ′ = 0.2 ° obtained in the above agrees well with the effective value of the current flowing through the armature coil. You can see that it has been corrected.

  As described above, according to the advance angle simulation of this embodiment, (1) there is a position detection error due to the hysteresis circuit to prevent malfunction, and (2) a position detection error due to the influence of the armature magnetic flux. In consideration of this, the three-dimensional magnetic field analysis process is repeated until the position detection error due to the influence of the armature magnetic flux due to the increase or decrease of the load torque is converged, and the converged position detection error is calculated to obtain the advance value. Therefore, it becomes possible to simulate an optimal advance value on a computer. As a result, the optimum advance value can be determined without manufacturing a plurality of actual machines and repeating the experiment, and the design cost can be greatly reduced.

(S501)-(S506) ... each step of FIG. 5, (S901)-(S914) ... each step of FIG. 9, (S2201)-(S2206) ... each step of FIG.

Claims (2)

In regard to a motor comprising a stator around which a winding is wound, a rotor having a magnet, and position detecting means for detecting the position of the rotor by measuring the magnetic flux density of the magnet, the stator winding A control parameter including an advance value for controlling the energization timing of the wire, a shape parameter for specifying the shape of the motor, a magnetic characteristic parameter including a magnetic flux density of the magnet, and a motor including a rotation speed of the rotor A simulation method for simulating the magnetic flux density and the motor efficiency by inputting a driving state parameter and performing a three-dimensional magnetic field analysis process on a computer,
An input procedure for inputting the parameters;
A three-dimensional magnetic field analysis processing procedure for performing the three-dimensional magnetic field analysis processing by a computer based on the inputted parameters and obtaining at least the magnetic flux density to be detected by the position detecting means as a result of the three-dimensional magnetic field analysis processing; ,
The position of the rotor position detection signal based on the magnetic flux density of the magnet to be detected by the position detection means based on the magnetic flux density to be detected by the position detection means due to the influence of the magnetic flux from the stator A position detection error calculation procedure for calculating a detection error;
The position detection error is added to the advance value, and the three-dimensional magnetic field analysis processing procedure and the position detection error calculation procedure are repeated to obtain a convergence determination procedure for determining whether or not the position detection error converges. An advance angle simulation method characterized by simulating the advance angle value obtained by adding the converged position detection error to the advance angle value and the motor efficiency based on the advance angle value. In regard to a motor comprising a stator around which a winding is wound, a rotor having a magnet, and position detecting means for detecting the position of the rotor by measuring the magnetic flux density of the magnet, the stator winding A control parameter including an advance value for controlling the energization timing of the wire, a shape parameter for specifying the shape of the motor, a magnetic characteristic parameter including a magnetic flux density of the magnet, and a motor including a rotation speed of the rotor A simulation program for simulating magnetic flux density and motor efficiency as a result of a three-dimensional magnetic field analysis process by inputting an operating state parameter and performing a three-dimensional magnetic field analysis process with a computer,
In a computer having a CPU, a memory, an external storage device, and an input device,
An input procedure for recording each parameter input by the input device in an external storage device;
A three-dimensional magnetic field analysis process performed by the CPU based on the input parameters to obtain at least a magnetic flux density to be detected by the position detection means as a result of the three-dimensional magnetic field analysis process and store it in the memory Magnetic field analysis processing procedure;
The influence of the magnetic flux from the stator on the position detection signal of the rotor based on the magnetic flux density from the rotor to be detected by the position detecting means based on the magnetic flux density to be detected by the position detecting means. A position detection error calculation procedure for calculating the position detection error by the CPU and storing it in the memory;
By adding the position detection error to the advance value and repeating the three-dimensional magnetic field analysis processing procedure and the position detection error calculation procedure, and a convergence determination procedure for determining whether or not the position detection error converges by the CPU. The obtained convergence position detection error is added to the advance value, and the advance value obtained by calculating by the CPU and the motor efficiency based on the advance value are stored in the memory as simulation results. A featured advance angle simulation program.

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