TWI617107B - Motor control unit - Google Patents

Abstract

In the present invention, temperature management of each part of the motor, such as a stator and a rotor, is performed, and when an overload is detected at a specific portion, it is started as a motor overload to start notification or specific control. The motor control device according to the present invention includes a control unit that detects a total loss between the input power and the output power of the AC motor, and obtains the deviation between the total loss and the total heat dissipation amount per unit time of the AC motor. Calculating the temperature of the AC motor based on the heat, determining the overload of the AC motor based on the temperature; and the control unit calculates the stator winding temperature from the heat of the stator winding of the AC motor, and calculates the heat from the rotor of the AC motor. The rotor temperature is compared with the respective threshold values, and when either of the threshold values is reached, the AC motor is overloaded to perform at least one of an output of the external notification signal and a decrease or a stop of the power supply of the AC motor.

Description

Motor control unit

The present invention relates to a motor control device and to a motor control device for performing overload protection of an AC motor.

In general, in general-purpose induction motors (inductive motors) that use inverters to drive speed control of air conditioners and conveyors, such as fan pumps, in various industrial plants, etc. Permanent magnet brushless DC (Direct Current) motor. In addition, for applications such as speed, torque, and position control for semiconductors, electronic component manufacturing and assembly machines, and forging machines, permanent magnet type AC (Alternating Current) servo motors or vector control inverter drives are used. Induction motor for rapid acceleration and deceleration or positioning control using excellent servo performance. In the forging machine, the press body is used for punching and drawing the automobile body from the press, and the drive motor uses an AC servo motor having excellent low-speed and high-torque characteristics. In one example of a press using an AC servo motor, the acceleration, deceleration, and up and down movement of the slider can be repeated, and in the mold extension, the high speed of the slider is rapidly decelerated to the machining speed immediately before reaching the material. The drawing process is performed at a low speed, thereby preventing the mold from ablation due to temperature rise, improving the dimensional accuracy of the outer diameter of the molded product, and temporarily stopping the sliding member during the pressurization process, thereby causing the hydraulic device to operate, etc. Forming that is difficult to achieve in a prior press can also be easily performed. Both the induction motor and the permanent magnet type motor have a tendency to increase the temperature of the motor due to the requirement of high-speed rotation or high-torque repeated load. The temperature of the motor has a large influence on the output fluctuation and the load of the part, so temperature management becomes an important issue. As a method of managing the motor temperature, for example, Patent Document 1 discloses a technique of providing an electronic thermal protector on a stator to monitor an electric current and monitor an overload of the motor. Further, Patent Document 2 discloses a technique in which a temperature detector for detecting a temperature rise of a stator winding is built in a motor, and a detected value thereof is monitored, thereby protecting the motor from an overload. Further, Patent Document 3 discloses a technique of estimating the motor winding temperature from the value obtained by subtracting the output power of the motor from the input power of the motor, and estimating the motor winding temperature, thereby performing motor overload protection. Further, Non-Patent Document 1 discloses a method of reducing loss and loss of a motor. For example, in Fig. 21 on page 32, as the loss, there are four types of copper loss, floating load loss, iron loss, and mechanical loss. The copper loss and floating load loss increase with the increase of the load rate, and the iron loss and mechanical loss are fixed, which is not affected by the variation of the load rate. The iron loss depends on the magnetic flux density of the magnetic circuit of the motor. The copper loss includes a primary copper loss caused by the winding resistance of the motor and a secondary copper loss generated on the rotor side of the induction motor. The rotor is a permanent magnet AC servo motor and a DC brushless motor (hereinafter, referred to as DCBL (Direct). Except in the case of Current Brush Less, DC Brushless Motor. CITATION LIST Patent Literature Patent Literature 1: Japanese Patent Laid-Open Publication No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. 1: Special edition IM&PM Motor "Induction motor and PM motor", data provided: Hitachi production system (shares), editor: Ohmsha (shares) (New Electric 2012, February issue, selected prints, Volume 66, No. 1, No. 841 , No. 842) Issued on March 1, 2012

[Problem to be Solved by the Invention] Here, the induction motor is formed with a cage winding on the rotor, and the cage winding is actually a bar and a tip which are made of a material having good workability in die casting such as aluminum. A ring-formed aluminum die-cast rotor, or a strip-shaped rotor in which a conductor bar (copper material) is inserted into a slit of a core to join an end ring and a guide bar. The secondary current flows through the cage conductor. The voltage induced by the cage conductor on the secondary side is determined by the winding ratio of the primary winding of the stator and the secondary winding of the rotor. In general, the number of windings on the rotor side is a die-cast structure or a strip rotor that joins the end ring and the guide bar as described above, so that it is difficult to form a complicated structure. Therefore, the number of secondary side windings is smaller than that of the primary side, and the induced voltage is low. On the other hand, since the electric power flowing from the primary side to the secondary side is equivalent to ignoring the efficiency, the secondary voltage is lowered, and accordingly, the secondary current is larger than the current on the primary side. In the continuous use of the output shaft of the motor repeatedly with the variable speed acceleration, deceleration, pressure holding or servo locking, the secondary current increases inversely proportional to the primary current and the winding ratio, and the secondary copper loss It is generated in accordance with the square of the current, so the temperature on the rotor side becomes extremely high. Since the heat is formed from the rotor through the stator to the cooling fin of the motor surface, and the structure is cooled by heat conduction, there is a problem in cooling efficiency. Further, in the same manner as the induction type motor, the permanent magnet type motor performs overload protection of the motor by an electronic thermal protector that monitors the motor current on the stator side, or a built-in temperature detector in the stator winding to perform motor overload protection. However, the permanent magnet type motor exists in a high-speed region, and even if the load torque is equal to or lower than the rated torque, the temperature rise of the motor is large, and the iron loss has a large influence on the temperature rise. The iron loss is caused by the loss of the core and is generated by the change of the magnetic flux passing through the core. There is also a rise in the temperature of the permanent magnet outside the core. Regarding the hysteresis loss and the eddy current loss of the iron loss, the eddy current loss of the permanent magnet in the high-speed region is increased, and the magnet itself generates heat and the temperature becomes high. If the temperature of the permanent magnet becomes higher, the demagnetization level is lowered. The permanent magnet is supplied with a chopper current including a high-frequency component from a stator winding driven by a PWM (Pulse Width Modulation) inverter having a carrier frequency of several k to several tens of kHz. The current including the high-frequency chopping generates a magnetic flux accompanied by chopping in the core or permanent magnet of the motor, and generates hysteresis loss and eddy current loss, that is, iron loss. Also, it is necessary to consider the effect of the current including the high frequency chopping on the demagnetization of the permanent magnet. The electronic thermal protector that changes with the increase or decrease of the iron current with the motor current cannot be overload protected. Moreover, the higher the performance of the permanent magnet, the more significant the influence of iron loss, and the influence of iron loss in the permanent magnet having a low magnetic flux density has not been a problem. In this regard, Patent Document 3 discloses that the motor output voltage is subtracted from the input power of the motor, and the heat loss is subtracted from the value, thereby estimating the motor winding temperature and performing motor overload protection. The overload protection by the secondary current of the rotor of the motor or the overload protection by the temperature rise of the permanent magnet of the rotor of the permanent magnet type motor is not disclosed. Further, the load in the servo press is a repeated load use or a repeated use of a repeated load (herein, referred to as "repetitive load"), and in a motor that operates with a repeated load, in one cycle of repeatedly applying the load, When the peak value of the motor torque reaches several times the rated torque, the corresponding motor loss is accumulated in the motor. The heat accumulated in the inside of the motor is radiated from the cooling fins on the stator side from the motor surface. However, there is a gap (gap) between the rotor and the stator on the rotor side, and it is necessary to dissipate air and dissipate heat through the cooling fins of the stator from the motor surface. Therefore, the cooling on the rotor side is significantly lower than that on the stator side. Regardless of the type of motor, temperature management including the rotor is important, but since the rotor is not in a stationary state, it is difficult to provide the electronic thermal protector or temperature detector disclosed in Patent Document 1 or 2 on the rotor. To manage the temperature. Thus, a technique for detecting the overload of the motor not only on the stator side but also on the rotor side is expected. Further, it is expected that, regardless of the form and specification of the motor, when an overload is detected at a specific portion of the motor, it is a technique for starting the notification or specific control as an overload of the motor. [Technical means for solving the problem] In order to solve the above problems, for example, a configuration of a patent application scope is applied. That is, a motor control device includes a control unit that detects a total loss between the input power and the output power of the AC motor, based on the total loss and the total heat dissipation per unit time of the AC motor. Calculating the temperature of the AC motor based on the heat obtained by the deviation, determining the overload of the AC motor based on the temperature; and the control unit calculates the stator winding temperature from the heat of the stator winding of the AC motor, from the AC motor The heat of the rotor calculates the rotor temperature and compares with the respective thresholds. When either of the thresholds is reached, it is determined that the AC motor is overloaded and the output of the external notification signal is executed, and at least the power supply of the AC motor is reduced or stopped. One. [Effect of the Invention] According to the present invention, the overload protection of the motor can be performed in consideration of the temperature of other motor components represented by the rotor in addition to the stator. Further, by managing the overload in units of the respective constituent elements, it is possible to realize the management of the motor overload excellent in versatility without being restricted by the form and specifications of the motor. Other problems, configurations, and effects of the present invention can be obtained from the following description.

Hereinafter, a motor power conversion device 100 to which an embodiment of the present invention is applied will be described using a drawing. Further, in the present embodiment, the motor power conversion device 100 includes an AC servo amplifier, a DCBL controller, an inverter, a vector control inverter, and the like, and may be a relay or the like if it is configured to include an arithmetic unit or the like. . First, the outline of the overload protection of this embodiment will be described. Regardless of the inductive (IM) motor or the permanent magnet (PM) motor, the AC motor acts to convert electrical energy into working energy. However, the input power Pin input to the AC motor is not all utilized as working energy, and a part of it is consumed as internal loss, heat, and thus sound of the motor. The electric power of the operating energy is the output electric power Pout, which imparts a torque Tf and a rotational speed Nf to the load connected to the motor. Inputs and outputs can be expressed in units of W (watts). When the input is set to Pin (W) and the output is set to Pout (W), the relationship between the motor efficiency η and the loss Ploss (W) can be expressed by (Expression 1) and (Expression 2). [Expression 1] (Expression 1) η = (Pout / Pin) × 100 (%) Here, η: efficiency of the motor Pin: input power of the motor (W) Pout: output power of the motor (W) Equation 2] (Expression 2) Ploss=Pin-Pout (W) Here, Ploss: Total loss of motor (W) In the present embodiment, the physical quantity which is the basis of the motor heat is regarded as the total loss amount of the motor Ploss Instead of motor current. Calculating the total loss by accumulating the losses is more complicated, but the total loss can be obtained without knowing the loss details. That is, as shown in (Expression 2), the total loss amount Ploss of the motor can be obtained by subtracting the output power Pout from the input power Pin of the motor. In the motor loss, the iron loss is divided into hysteresis loss and eddy current loss, and the loss remains unchanged even if the motor current increases. Therefore, regarding the hysteresis loss and the eddy current loss, the experimental formula of Steinmetz has been known from the past, and the hysteresis loss Ph is as follows (Expression 3), and the eddy current loss Pec is as follows (Expression 4) . [Expression 3] (Expression 3) Ph=Kh×f×Bm ^1.6 Here, Kh: proportional constant, f: frequency, Bm: maximum magnetic flux density [Expression 4] (Expression 4) Pec = Ke × (t × f × Bm) ² /ρ Here, Ke: proportional constant, t: iron plate thickness, f: frequency, Bm: maximum magnetic flux density, ρ: resistivity hysteresis loss of magnetic body is proportional to frequency (motor speed), eddy current loss and frequency The square of (motor speed) is proportional, so the loss becomes particularly large in the high speed region. Further, a motor power conversion device that drives a motor by a PWM (Pulse Width Modulation) waveform is supplied with a chopping current including a high frequency component having a carrier frequency of several k to several tens of kHz. The current including the high-frequency chopping wave is a magnetic flux accompanying the chopper in the core or permanent magnet of the motor, which causes hysteresis loss and eddy current loss, that is, iron loss. The iron loss can be obtained by magnetic field analysis and simulation based on the core of the stator or the rotor, the material of the permanent magnet of the rotor in the permanent magnet type motor, the thickness of the plate, and the shape of the cross-sectional hole. The motor output power Pout can be obtained by (Expression 5). Here, the motor rotation speed Nf and the torque Tf are obtained by calculation in the motor power conversion device 100 by the value controlled by the motor power conversion device 100. Furthermore, in the case of an inverter, by the sensorless vector control, even if there is no speed sensor such as an encoder in the motor, the rotation speed of the motor can be estimated to suppress the load variation rate to be small. The high-precision speed control can be used to calculate the motor output power Pout using the estimated rotational speed Nf of the motor used in the sensorless vector control. [Expression 5] (Expression 5) Pout=(2π/60)×Nf×Tf (W) Here, Nf: motor rotation speed (1/min) Tf: motor torque (N·m) (2π/60=0.1047) Next, the motor input power Pin is expressed by (Expression 6). The motor input power Pin is the same as the above, and is an output of the motor power conversion device, and is a value used in the device, and can be easily calculated. [Expression 6] (Expression 6) Pin = √ 3 × V × I × cos θ (W) = 3 × Vs × I × cos θ (W) Here, V: motor line voltage (V) Vs: motor Phase voltage (V) I: motor current (A) cos θ: power factor. Alternatively, as another method of determining the motor input power Pin, it is also possible to calculate the instantaneous phase voltage and phase current applied to the motor. The product of the values is obtained by (Expression 7) the sum of the powers of the phases of the U, V, and W phases of the motor. [Expression 7] (Expression 7) Pin=Vu·Iu+Vv·Iv+Vw・Iw (W) Here, if the instantaneous phase voltages are Vu, Vv, and Vw, the phase voltage effective value is Vrms. When the angular frequency of the power supply is ω and the time is t, the following (Expression 8-1) to (Expression 8-3) and (Expression 9-1) to (Expression 9) -3) Substituting into (Expression 7) for calculation, the input power Pin of the motor can be obtained by (Expression 10). [Equation 8-1] (Expression 8-1) Vu=√2・Vrms・sin(ωt) (V) [Expression 8-2] (Expression 8-2) Vv=√2・Vrms・sin (ωt+2π/3) (V) [Expression 8-3] (Expression 8-3) Vw=√2・Vrms・sin(ωt+4π/3) (V) Also, if the instantaneous phase current is set to Iu , Iv, Iw, the phase current rms value is expressed in Irms, and the phase angle is expressed in φ, then [Equation 9-1] (Expression 9-1) Iu=√2・Irms·sin(ωt+φ) (A) [Equation 9-2] (Expression 9-2) Iv=√2・Irms・sin(ωt+2π/3+φ) (A) [Formula 9-3] (Expression 9-3) Iw=√2・Irms・sin(ωt+4π/3+φ) (A). [Equation 10] (Expression 10) Pin=3・Vrms・Irms・cosφ (W) The total loss Ploss of the motor obtained by the above (Formula 2) is the amount of change in the previous motor current. The calculation is performed in accordance with (motor input power) - (motor output power), that is, Pin-Pout. When the total heat of the motor is set to Q1 (J), the total loss Ploss can be time-integrated and expressed by (Expression 11). [Expression 11] (Expression 11) Q1=∫Plossdt (J) Here, Q1: Total heat of the motor (J) Ploss: Total loss of the motor (W) Furthermore, the motor actually contains various parts and each The material is also different, so there is a difference in the specific heat c1 of the motor electrical part + the casing. Therefore, the measurement of the specific heat c1 of the motor electric part + the casing is suitably performed in such a manner that (the cooling fan does not rotate) the position where the temperature of the motor is determined, while maintaining the heat insulation state with respect to the circumference, and fixing the motor stator winding The loss Ploss is measured by measuring the temperature rise ΔTc1 of the motor casing by (Expression 12). Furthermore, the reason why the specific heat of the motor is set to the equivalent specific heat is that the motor contains various materials, and if the measurement site changes, the temperature rise value changes accordingly, so the specific measurement site must be used, and the equivalent specific heat is used according to the specific heat of the site. To represent. [Expression 12] (Expression 12) c1 = Ploss × t / (m1 × ΔTc1) Here, c1: equivalent specific heat of the motor (J/kg·K) Ploss × t: heat introduced per unit time (J M1: mass of motor (kg) ΔTc1: rise temperature (K) of motor electric part + housing t: time (s) used to increase ΔTc1 If the equivalent specific heat c1 of the motor is obtained by (Expression 12), Then, the total heat amount Q1 generated inside the winding of the motor (including the core body or the like) is obtained by (Expression 11) and accumulated in the motor casing, and the temperature rise of the motor casing (heat storage portion) Tc1 can be obtained by (Expression 13 And find it. [Equation 13] (Expression 13) Tc1=Q1/(m1・c1) (K) Here, Tc1: temperature rise of motor housing (heat storage unit) (K) (temperature of motor housing (heat storage unit)) (°C) The ambient temperature of the motor is required. Ta) Q1: Heat of the motor (J) m1: Mass of the motor (kg) c1: Equivalent specific heat of the motor case (heat storage unit) (J/kg・K) When the heat of the stator is set to Q2 (J), the mass of the stator is m2 (kg), and the equivalent specific heat of the stator winding is c2 (J/kg·K), the temperature of the stator winding of the motor rises by Tc2 (K). ) is shown as (Expression 14). [Expression 14] (Expression 14) Tc2 = Q2 / (m2 · c2) (K) Here, Tc2: temperature rise (K) of the motor stator winding (the temperature of the motor stator winding (°C) needs to be added to the motor Ambient temperature Ta) Q2: Heat of motor stator (J) m2: Mass of motor stator (kg) c2: Equivalent specific heat of motor stator winding (J/kg・K) If the heat of the rotor is set to Q3(J), When the mass of the rotor is m3 (kg) and the equivalent specific heat of the cage conductor of the rotor is c3 (J/kg·K), the temperature rise of the cage-shaped conductor of the induction motor is Tc3(K) ( Equation 15) is shown. Further, when the temperature of the permanent magnet of the rotor of the permanent magnet type motor rises by Tc3 (K) (indicated by the same symbol as that of the induction motor), if the heat of the rotor is set to Q3 (J), the mass of the rotor is set. In the case of m3 (kg), the equivalent specific heat of the permanent magnet of the rotor is c3 (J/kg·K), and the temperature rise value can be expressed by the same formula as (Expression 15). [Equation 15] (Expression 15) Tc3 = Q3 / (m3, c3) (K) Here, Tc3: The temperature of the cage conductor of the rotor of the motor rises (K) ・ When the induction motor is used: When the temperature of the permanent magnet of the motor rotor rises (K) ・・・When the permanent magnet type motor is used ( The temperature of the cage conductor of the rotor of the motor (°C) and the temperature of the permanent magnet (°C) are added to the ambient temperature of the motor. ) Q3: Heat of the motor rotor (J) m3: Mass of the motor rotor (kg) c3: Equivalent specific heat of the cage conductor of the motor rotor (J/kg・K) ・In the case of an induction motor: Permanent motor rotor The equivalent specific heat of the magnet (J/kg・K). In the case of the permanent magnet type motor, if the heat of the bearing or the like is Q4 (J), the mass of the bearing or the like is set to m4 (kg). When the equivalent specific heat of the bearing is c4 (J/kg·K), the temperature rise of the bearing of the motor Tc4 (K) is (Expression 16). [Expression 16] (Expression 16) Tc4=Q4/(m4・c4) (K) Here, Tc4: the temperature rise of the bearing of the motor (K) (the temperature of the bearing of the motor (°C) is added to the motor Ambient temperature Ta) Q4: Heat of motor bearing (J) m4: Mass of motor bearing, etc. (kg) c4: Equivalent specific heat of motor bearing (J/kg・K) Here, most of the loss of the motor is heat The form spreads (propagates) to various parts of the motor. For example, it is conducted by fixing a metal solid such as a metallurgical tool, or is released into the atmosphere by natural or forced convection from a cooling fin on the surface of the motor. Or, some of them are scattered around the sound. In either case, heat transfer can be expressed (Expression 17). [Expression 17] (Expression 17) Qf=α・(Tc1-Ta)・(kf×A) Here, Qf: heat dissipation (heat transfer) amount per unit time, J/s, (kcal/h) α: heat transfer coefficient W/m ² K, (kcal/m ² hK) Tc1: temperature K of the heat transfer surface, (°C) Ta: temperature of the atmosphere (fluid) K, (°C) kf: forced cooling coefficient A: surface area of the solid (heat transfer area) m ² (m ² Further, as a formula for calculating a temperature rise value by a cooling fin or the like, there is a thermal resistance Rth (° C/W). Although the thermal resistance can provide a loss value (W) in a steady state, the temperature rise value in the temperature saturation state is calculated to be several degrees (K), but even when the load applied to the motor changes instantaneously, even if it is instantaneously changed It is also impossible to obtain an excessive temperature by multiplying the loss value (W) by the thermal resistance. Therefore, one of the features of the present embodiment is that the motor is represented by a heat transfer function, and the temperature rise value of the motor casing is calculated by (Expression 13), and the difference between the temperature rise value of the motor casing and the ambient temperature is obtained. The amount of heat dissipated from the motor per unit time is calculated from the temperature difference of the motor casing by (Expression 17). According to the difference between the total loss Ploss generated from the motor and the heat dissipation amount Qf emitted from the motor per unit time, the current value of the total loss held by the motor is calculated, from the current value of the total loss (Expression 14 Calculating the temperature rise value of the motor stator winding, and calculating the temperature rise value of the motor rotor by (Expression 15), and calculating the temperature of the bearing portion supporting the rotor by the stator of the motor by (Expression 16) The rising value compares the temperature rise value of each part with the threshold value determined to be overloaded, and when any part detects the overload first, it outputs it as an overload of the motor. The above is an outline of the overload protection process of the motor power conversion device 100 of the present embodiment. Hereinafter, each embodiment will be described in detail with reference to the drawings. In FIG. 2, the case where the motor power loss of the motor power conversion device 100 "power running" is schematically represented. A system 1 motor that rectifies a power source supplied from an AC power source 2 by a full-wave rectification converter 5 with a power converter regenerative function, and converts it into a DC voltage by a smoothing capacitor 8 . Next, the inverter 9 is again converted from the DC power source to the AC power to supply electric power to the motor 1. The inverter 9 is provided with n-phase n-phase, and the ARM is connected in parallel with the switching element 10 and the freewheeling diode 11 in parallel, and is connected in series to the upper (P side) and the lower (N side). In the figure, the 3 phases of 3 ARM are illustrated. The switching element 10 is subjected to PWM (Pulse Width Modulation) control by switching of a power circuit. Further, the motor 1 applies a rotational speed Nf and a torque Tf to the motor output shaft and supplies it as power to the load, thereby driving the machine. Here, the width of the arrow of the motor 1 shown in Fig. 2 indicates the degree of power. In the power running state, the motor 1 obtains the input electric power Pin and outputs the motor output Pout, so the magnitude relationship is the input electric power Pin>the output electric power Pout, and the smaller amount becomes the loss Ploss. Most of this loss Ploss becomes the heat of the motor. Further, in the power running operation, the power regeneration converter 6 of the inverter 4 with the power regeneration function is in a suspended state. FIG. 3 schematically shows the state of motor loss during "regeneration" of the motor power conversion device 100. This figure shows, for example, when the motor 1 is a motor for an elevator that performs four-quadrant operation. The motor for the elevator is moved up and down in the vertical direction. When the vehicle is lowered, the load is prevented from falling in the direction of gravity, and the motor torque is output in the rising direction and the speed is smoothly changed in the descending direction. The regenerative action system carrier is dropped by gravity, whereby the motor output shaft is rotated from the outside. Therefore, the motor is in a power generation state, and energy for power generation (regeneration) passes through the inverter 9 from the motor 1, and electric power (regeneration) energy is charged to the smoothing capacitor 8. The electric power (regeneration) energy stored in the smoothing capacitor 8 is regenerated to the AC power supply 2 through the regenerative AC reactor 7 by the 6-stage power regeneration converter. At this time, if the relationship between the motor input power Pin and the output power Pout is viewed in terms of the flow of energy, the power from the load (mechanical) side is passed through the motor, via the inverter 9, the smoothing capacitor 8, and the power supply of the inverter 4 with the power regeneration function. The regenerative converter 6 and the regenerative AC reactor 7 are regenerated to the AC power source 2. At this time, the direction of the arrow of Pin and Pout of the motor 1 is opposite to that of FIG. 2, and the width of the arrow (the degree of power) becomes the maximum motor output Pout and the input power Pin is small, and the magnitude relationship becomes (input power Pin) The absolute value is < (the absolute value of the output power Pout), and the amount that becomes smaller becomes the loss Ploss. Most of this loss Ploss becomes the heat of the motor. Further, in the regenerative operation, the full-wave rectifying converter 5 of the inverter 4 with the power regeneration function is in a suspended state. Further, in FIGS. 2 and 3, since the input power Pin and the output power Pout are processed in the four-quadrant operation, the power running state of FIG. 2 is defined as the positive direction. In this case, the input power Pin and the output power Pout in FIG. 3 as the reproduction state become negative values. Here, it is verified by (Expression 2) whether or not the direction of the motor loss shown in FIG. 3 is a positive value. In FIG. 3, the input power Pin and the output power Pout are negative values, and (the absolute value of the input power Pin) < (the absolute value of the output power Pout), so Pout is large in terms of the absolute value. If (-small) indicates Pin and (-large) indicates Pout, then (Expression 2) Ploss=Pin-Pout=(-small)-(-large)=(-small+large)>0, Ploss becomes Positive value. As can be seen from the above, the direction of Ploss in Fig. 3 is the same direction as that of Fig. 2. In Fig. 4, the state of the motor loss when the motor power conversion device of the DC power source is regenerated is schematically shown. 2 and 3 are supplied by the AC power supply. Therefore, the DC power supply is obtained by the inverter, and the inverter is again converted into the AC power supply. However, the power supply regeneration function is not required in the supply of the DC power supply (battery). Shunner 4. Since the figure is in the regenerative state, the energy for power generation (regeneration) passes through the inverter 9 from the motor 1, and the electric power (regeneration) energy is charged to the smoothing capacitor 8. Therefore, the motor 1 and the inverter 9 are the same as those in Fig. 3. The difference from FIG. 3 is that the AC power source 2 is changed to a DC power source (battery) 3, and the DC power source (battery) 3 is directly regenerated and charged while the electric current (regeneration) energy is charged to the smoothing capacitor 8. The magnitudes of the positive and negative polarities and the absolute value of the input power Pin and the output power Pout are the same as those in FIG. 3, and thus the description thereof is omitted. Further, since the inverter 4 with the power regeneration function of Fig. 2 is a DC output, the description of the motor loss during power running is the same as that of the inverter 9 of Fig. 2. Fig. 5 is a view for explaining an example of using a repetitive load from the number of revolutions and torque of the motor for a press. An example is disclosed in which a press is a structure in which a rotary motion of a motor is converted into a reciprocating motion by a crank mechanism, and a slider is moved up and down to perform a thin plate drawing process at a bottom dead center. The top view of Fig. 5 shows the motor speed. The slider runs in the forward rotation mode from the top dead center. Before it reaches the sheet material near the bottom dead center, it stops and maintains the position to prevent the mold from ablation, and then descends again to press the extension. machining. After fully pressing the machining, the motor runs in the same forward direction, the slider rises and returns to the top dead center, ending 1/2 cycle. The lower diagram of Fig. 5 shows the torque of the motor, which accelerates in the power running direction in the falling 1 and operates at the regenerative torque at the constant speed and the deceleration stop, and the press-fed extension becomes the power running. When the slider returns to the top dead center, the motor still maintains the forward direction, and runs in the power running mode during acceleration and constant speed, and stops in the regeneration mode when decelerating. When the operation is repeated, the motor lowers the slider in the reverse direction, stops immediately before reaching the sheet material near the bottom dead center, and holds the position to prevent the mold from ablation, and then descends again to press the extension processing. After fully pressing the machining, the motor runs in the same reverse direction, the slider rises and returns to the top dead center, and the remaining 1/2 cycle ends. The motor rotates once in the forward rotation operation and rotates once in the reverse rotation operation, so that the slider can perform two extension machining operations. When the action is performed at a high speed, the slider is rotated forward from the midpoint between the top dead center and the bottom dead center, and the drawing is performed at the bottom dead center, and is stopped in the forward rotation mode at the intermediate point on the opposite side. The reset system starts in reverse mode and performs the extension processing at the bottom dead center, and returns to the original intermediate point by inversion. This operation is to fix the fulcrum of the crankshaft on the flywheel that performs circular motion, and the fulcrum swings like a pendulum of a clock, so it is called pendulum operation. When the rotation angle of the fulcrum is less than 180°, the production time is small, the load ratio of the motor is increased, and continuous use as a repeated load tends to be in the direction of overload, and therefore sufficient overload protection is required. Fig. 6 is a view for explaining the loss in the "motor speed-torque characteristic" of "power running" in the present embodiment. In the figure, the horizontal axis represents the rotational speed Nf, and the vertical axis represents the (power running) torque Tf, and the maximum torque of the motor is indicated by the line connecting the points Α-BCD. Further, the rated output point P0 at which the rated torque of the motor is Tf0 and the rated rotational speed is Nf0 is shown in the figure. Secondly, it will pass the rated output curve of the rated output point (Tf=9. 55 × P0 / Nf) is shown on the graph. The curve is a motor output Pout curve expressed in terms of speed-torque. Secondly, since (Pin 2), Pin=Ploss+Pout is known. Therefore, if the motor loss is included in the motor output Pout constant curve, the input power Pin is a constant curve. In addition, in the figure, an example of mechanical loss, iron loss, floating load loss, and copper loss is shown. In the low-speed, high-torque region, the ratio of copper loss to total loss is dominated by the increase in current. Although the iron loss is not affected by the current, the hysteresis loss is proportional to the frequency, and the eddy current loss increases according to the square of the frequency. Therefore, especially in the permanent magnet type motor, in the high-speed region where the motor voltage is saturated and the maximum torque is reduced, the ratio of the iron loss in the total loss is rapidly increased and dominates. Fig. 7 is a view for explaining the loss in terms of "motor rotation speed-torque characteristic" at the time of reproduction in the present embodiment. In the figure, the horizontal axis represents the rotational speed Nf, and the vertical axis represents the regenerative torque Tf, and the regenerative torque Tf is marked with a negative scale with respect to setting the power running torque to a positive scale. The regenerative operation rotates the motor shaft from the machine side, the output power Pout becomes maximum, and then the energy is regenerated to the input power source, and the input power Pin is minimized. Further, in the figure, each loss is omitted, and the portion sandwiched between the input power Pin and the output Pout is the total loss Ploss. Among the total losses, the copper loss is dominant in the maximum torque region in the low speed region, and the iron loss increases in the region where the maximum torque is limited in the high speed region. Further, in the induction motor, when the DC voltage (the voltage between PN) rises by the regenerative energy during the regeneration, the pulse of the PWM waveform is not controlled so as to be fixed to the (voltage) V/(frequency) F of the motor. In the case of width, the iron loss increases. In Fig. 8, the types of losses generated in various parts of the motor are shown. The losses generated in various parts of the inductive motor and the permanent magnet motor are roughly classified into fixed loss and load loss. The fixed loss includes iron loss and mechanical loss irrespective of the load size, and the load loss is the copper loss and floating load loss which are increased or decreased according to the load size. The copper loss shown in the figure is generated in the primary winding and the secondary winding, and is generated by the relationship of (square of current) × (winding resistance). The copper loss is generated by the induction type and the stator winding of the permanent magnet type motor, the cage conductor of the induction type motor, and the strip conductor. The floating load loss is a loss due to the eddy current flowing through the metal portion other than the conductor or the core due to the flow of the load current. The floating load loss is generated in the motor case, the cover, etc., and is a part that is difficult to measure or measure. The iron loss includes hysteresis loss and eddy current loss, which are related to the increase of the frequency (motor rotation speed) and the maximum magnetic flux density, and are generated by the permanent magnet of the stator and the rotor core or the permanent magnet type motor. The iron loss can be obtained by (Formula 3) and (Formula 4). Further, in the inverter, the controller, and the servo amplifier driven by the PWM waveform, the iron loss caused by the carrier frequency of the high frequency applied to the motor is generated in the core and the permanent magnet. Mechanical losses include frictional losses between the shaft and the bearing, and wind losses due to friction between the rotor and the surrounding air. In the case where a cooling fan is used to cool the motor, the power consumption of the fan is also included in the mechanical loss. In Fig. 8, the losses are distinguished between the induction motor and the permanent magnet motor. As a part, the stator is divided into a core, a winding, etc., and the rotor is divided into a core, a cage conductor (inductive motor), and a permanent magnet ( For permanent magnet motors, etc., the stator and rotor are divided into bearings and fans. For the copper loss (primary and secondary), floating load loss, iron loss, and mechanical loss, the four types of losses are indicated by circles. In FIG. 9, the circuit configuration in the case where the motor power conversion device 100 is applied to an induction type motor is schematically shown. The motor power conversion device 100 is an inverter that drives the motor 1, a vector control inverter, an inductive AC servo amplifier, and the like. First, the autonomous circuit begins to explain. The full-wave rectifying converter 5 of the inverter 4 with the power regeneration function rectifies the power supplied from the AC power supply 2, and is parallelized by the smoothing capacitor 8 to be converted into a DC voltage (PN voltage). The inverter 9 converts the DC power source to an AC power source again, and is connected to the induction motor 1a via the U-phase and W-phase current detectors CTu12 and CTw13. Furthermore, the inverter 9 is provided with n ARM (three phases of 3 ARM in the figure), wherein the ARM is connected in parallel with the switching element 10 and the freewheeling diode 11 in parallel, and is connected in series between the PNs. The switching element 10 is PWM-controlled by a switch, and the induction motor 1a is capable of speed and position control, and applies power to the load to drive the machine. Further, the motor 1 is in a power generation state during the regenerative operation, and the regenerative energy is charged from the motor 1 to the smoothing capacitor 8 via the inverter 9. Further, the regenerative energy is returned from the smoothing capacitor 8 to the AC power source 2 via the power regeneration converter 6 via the regeneration AC reactor 7. The induction motor 1a includes an encoder 14a for position and speed detection on the motor shaft. Furthermore, the encoder 14a is not necessarily constructed when the motor power conversion device is in the absence of a sensor vector control inverter. The reason for this is that, in the case of no sensor vector control, the estimated rotational speed Nf of the motor to be processed by the internal operation can be used. In the case of the encoder 14a, the output of the encoder 14a mounted on the motor shaft is sent to the position of the control logic circuit 15, the speed operator 27, and the rotational speed Nf of the motor is output. Here, the subtracter 20 outputs the difference ε (= N - Nf) between the rotational speed Nf and the speed command N, and amplifies it by the speed controller (ASR) 21 to form a torque current command Iq. The torque current command Iq is output to the subtracter 20 that performs the operation of the difference from the torque current feedback signal Iqf, and is sent to the slip frequency arithmetic unit 30. Further, the rotation speed Nf signal is sent to the magnetic flux arithmetic unit 29, and the magnetic flux current command Id in which the magnetic flux weakening control mode is formed so that the base rotation speed is equal to or lower than the fixed magnetic flux and the base rotation speed or more is the fixed output control. The magnetic flux current command Id is output from the slip frequency computing unit 30 when the slip angle frequency ωs of the output is equal to the torque current when it is equal to or lower than the base rotational speed. Further, 31 is an angular frequency conversion constant (2π/60) and converted into an angular frequency ωr, and the operation of the angular frequency ω1 = ωr + ωs is performed by the adder 19. The angular frequency ω1 is converted to phase θ by the integrator 36 and sent to the dq/3-phase converter 24 and the 3-phase/dq converter 26. The U-phase current detector CTu12 and the W-phase current detector CTw13 detect the current of the induction motor 1a, and are input as a current feedback Iuf, Iwf signal to the 3-phase/dq converter 26 of the control logic circuit 15. 3-phase/dq conversion The device 26 converts the 3-phase Iuf and Iwf signals into Idf and Iqf signals which are orthogonally represented by the d and q axes. The difference between the magnetic flux current command Id and the magnetic flux current feedback signal Idf is obtained by the subtractor 20 and amplified by the d-axis current controller (ACR) 22. Further, the difference between the torque current command Iq and the torque current feedback signal Iqf orthogonal to the magnetic flux current command Id is obtained by the subtractor 20, and amplified by the q-axis current controller (ACR) 23. The outputs of the d-axis and q-axis current controllers (ACR) 22 and 23 are input to the dq/3-phase converter 24 as d-axis and q-axis voltage commands Vd and Vq, and the 3-phase voltage commands Vu, Vv, and Vw are output to The PWM circuit 25 is provided as a gate signal of the switching element 10 of the inverter 9, thereby controlling the inductive motor 1a. Next, the total loss calculation circuit 16 (dashed line) will be described. The motor current feedback Iuf and Iwf signals are converted into orthogonal Idf and Iqf signals by the 3-phase/dq converter 26, and the motor torque Tf is vector-operated by the torque operator 32. The torque signal Tf and the rotational speed Nf from the position and velocity calculator 27 are input, and the output Pout operator 33 performs an operation (Expression 5) to obtain the output power Pout. The current operator 34 calculates the current effective value I, inputs the phase voltage effective value from the dq/3 phase converter 24, and obtains the phase voltage, current, and power factor cos θ by vector operation, and then inputs the Pin operator 35 according to ( Equation 6) Calculates the input power Pin. The Pout and Pin calculated by the output Pout operator 33 and the input Pin operator 35 according to the above description are subjected to the Pin-Pout calculation of (Expression 2) by the subtractor 20, thereby calculating the total loss Ploss of the motor. The total loss Ploss of the motor is sent to the overload detecting circuit 17a to determine whether the motor is overloaded. When the overload detecting circuit 17a determines the motor overload based on the accumulated heat of the motor, the state of the heat radiation amount per unit time, and the temperature rise of each part of the motor, the overload detecting signal OL is sent to the protection processing circuit 18, and the overload display or the external output is output. The signal of the overload notification, and further, the motor is stopped for overload protection. Furthermore, the block diagrams of the speed controller (ASR) 21, the d-axis and the q-axis current controllers (ACR) 22, 23, and the PWM circuit 25 in the control logic circuit 15 described above are performed by the CPU (Central Processing). Unit, central processing unit) or DSP (Digital Signal Processor) and other computing devices and software cooperation. The block diagrams in the total loss operation circuit 16 are also realized by the cooperation of the arithmetic unit and the software. In Fig. 10, the circuit configuration in the case where the motor power conversion device is applied to the permanent magnet type motor is schematically shown. The motor power conversion device 100 includes an AC servo amplifier, a DCBL controller, and an inverter. First, regarding the main circuit, the inverter 4 with the power regeneration function, the inverter 9, the U-phase, and the W-phase current detectors CTu12 and CTw13 are the same as those applied to the induction motor (Fig. 9). The permanent magnet motor 1b includes an encoder 14b for detecting position, speed, and magnetic pole position on the motor shaft. Furthermore, in the case where the motor power conversion device 49 is a DCBL controller or an inverter, the encoder 14b is not necessarily constructed because, in the case of a sensorless DCBL motor, it can be controlled by vector control. speed control. Furthermore, the magnetic pole position detection is for detecting the position of the magnetic pole of the permanent magnet attached to the rotor of the motor. In the case of an encoder, the output of the encoder 14b mounted to the motor shaft is sent to the position, speed, and magnetic pole position operator 28 of the control logic circuit 15, and the rotational speed Nf of the motor is output. Further, the position, velocity, and magnetic pole position calculator 28 outputs the magnetic pole position signal θ to the dq/3-phase converter 24 and the 3-phase/dq converter 26. The subtractor 20 outputs the difference ε (= N - Nf) between the rotational speed Nf and the speed command N, and amplifies it by the speed controller (ASR) 21 to form a torque current command Iq. The current of the permanent magnet motor 1b is detected by the U-phase current detector CTu12 and the W-phase current detector CTw13, and a current feedback Iuf, Iwf signal is input to the 3-phase/dq converter 26 of the control logic circuit 15. . The 3-phase Iuf and Iwf signals are converted from the 3-phase Iuf and Iwf signals to Idf and Iqf signals which are orthogonally represented by d and q axes. The torque current command Iq is output to the subtracter 20 that performs the calculation of the difference from the torque current feedback signal Iqf, and the deviation is amplified by the q-axis current controller (ACR) 23. The d-axis current command Id is a current command when the magnetic field is weakened, and the difference between the d-axis current feedback signal Idf and the d-axis current feedback signal Idf is obtained by the subtractor 20, and the deviation is amplified by the d-axis current controller (ACR) 22. The outputs of the d-axis and q-axis current controllers (ACR) 22 and 23 are input to the dq/3-phase converter 24 as d-axis and q-axis voltage commands Vd and Vq, and then the 3-phase voltage commands Vu, Vv, and Vw are output. It is supplied to the PWM circuit 25 as a gate signal of the switching element 10 of the inverter 9, thereby controlling the permanent magnet type motor 1b. Next, the total loss calculation circuit 16 (dashed line) will be described. The calculation of the output power Pout and the input power Pin is the same as that of FIG. 9, and therefore will be omitted. The subtracter 20 performs a Pin-Pout operation of (Expression 2) to calculate the total loss Ploss of the motor. Sending the total loss Ploss of the motor to the overload detecting circuit 17b, and if the motor overload is determined based on the accumulated heat of the motor, the state of the heat dissipation per unit time, and the temperature rise of each part of the motor, the overload detection signal OL is sent to the protection processing circuit. 18, and output a signal for displaying an overload or reporting an overload to the outside, and then stopping the motor for overload protection. Furthermore, the calculation of Pin and Pout is not limited to the examples of FIGS. 9 and 10 described above. In Fig. 11, another configuration example of the detection of the input power is schematically shown. In FIGS. 9 and 10, the signal in the self-control logic circuit 15 is input to the input power Pin by the input Pin operator 35. However, in the example of FIG. 11, the phase voltages Vu, Vv are detected from the terminal voltage of the motor. In Vw, Iuf and Iwf are detected by U-phase and W-phase current detectors CTu12 and CTw13, and motor current calculation is performed. Specifically, the phase current Ivf is configured such that Ivf=-(Iuf+Iwf) is obtained from the three-phase current Iuf+Ivf+Iwf=0. The CPU of the control logic circuit 15 performs a product of the phase voltages of the U, V, and W phases and the instantaneous value of the phase current when performing the above calculation (Expression 7), thereby performing (Expression 8-1) to ( The product of the phase voltage of Equation 8-3) and the phase current of (Formula 9-1) to (Formula 9-3). Thereby, the CPU adds the input power amounts of the U phase, the V phase, and the W phase of each phase, thereby obtaining "3-phase input power Pin". The above is an outline of the circuit configuration of this embodiment. Next, an overload detecting circuit which is one of the characteristic portions of the present embodiment will be described. First, the motor overload detecting circuit 17a corresponding to the case of the induction type motor (Fig. 9) will be described. In Fig. 1, the details of the overload detecting means in the overload detecting circuit 17a of the induction type motor are shown. The overload detecting circuit 17a is divided into four functional units. First, the heat including the entire motor (motor electric part + casing) is processed by the first portion 37 (dashed line) which is a basic portion. Next, the second to fourth portions are divided into various parts of the motor. The second portion 45 is a stator, and the calculated temperature rise is for the stator winding. The third portion 46 is a rotor, and the calculated temperature rise is for a cage conductor. Furthermore, it is not limited to the cage conductor, and may be other aspects such as a strip rotor. Finally, the fourth part is a 47-series bearing, etc., and the calculated temperature rise is for the bearing. Further, the first portion 37 performs heat treatment of the entire motor (motor electric portion + casing), and of course includes heat of the second to fourth portions. In the first portion 37, the total heat accumulated per unit time and the total heat dissipated from the motor per unit time are accurately calculated from the total loss input to the motor, and the total heat accumulated in the motor per unit time at the current time point is calculated. It is regarded as the total loss current value Pe(W). The first portion 37 will be specifically described. The first portion 37 is a system (motor electric unit + casing), and the total loss Ploss (input electric power Pin-output electric power Pout) of the motor is input thereto. Second. The heat amount Qf radiated from the motor per unit time is subtracted by the subtractor 20 from the total loss Ploss (the amount of heat accumulated in the motor per unit time). The output is the amount of heat currently accumulated in the motor per unit time, and is obtained by the total loss current value Pe=Ploss-Qf. The total loss current value Pe is input to the motor heat storage unit 42-1 (transfer function: 1/(m1·c1・s)), and the total heat amount Q1 of the motor is calculated, and then the motor case is calculated by (Expression 13) The body temperature rise value Tc1 (K). Further, the motor case temperature Tc1 (° C.) is obtained by adding the motor case temperature increase value Tc1 (K) to the ambient temperature Ta (° C.) of the motor. The value of the casing temperature Tc1 (°C) of the motor after the ambient temperature Ta (°C) of the motor is added to the output of the overload determination circuit 43-1 and the subtractor 20 of the first portion 37. Then, the difference between the motor case temperature Tc1 (°C) and the ambient temperature Ta (°C) is obtained by the subtractor 20, and the motor heat dissipation unit 40 (transfer function: α·kf·A) performs the calculation (Expression 17). And output the heat dissipation amount Qf (J/s) per unit time. Here, kf represents a forced cooling coefficient, and kf=1 in the case of natural cooling. The total heat dissipation amount Qf (J/s) per unit time as the output of the motor heat radiating portion 40 is returned to the subtractor 20 which has been supplied with the total loss Ploss, thereby constituting a negative feedback loop. Furthermore, the motor is regarded as a thermal resistor, and the motor case is set to a thermal resistance Rth (°C/W) to provide a loss (W), thereby obtaining a temperature rise value of the motor, and the value can be compared with a threshold value. The protection against overload, but the temperature rise value obtained by using the thermal resistance Rth is only the temperature rise value in the thermal equilibrium state after the temperature saturation in the excessive state, that is, the solution (value) in the steady state. On the other hand, in the case of processing the loss of the load which changes with time like a repeated load, the total loss variation is provided, and the thermal resistance Rth cannot calculate the change of the temperature rise value of the excessive state in which the total loss of the process is continuously repeated. . In order to solve this problem, in the present embodiment, the accumulated heat, the amount of heat dissipated, and the temperature rise value are realized by processing the differential and integral transfer functions. Further, as one of the features of the first portion 37, the difference between the total loss Ploss and the total heat radiation amount per unit time is calculated by the subtractor 20. The heat dissipation of the motor is radiated from the cooling fins around the motor housing to the atmosphere, or is thermally conducted from the base mounting portion of the motor to the object side mounting base (fixing plate). Although it is difficult to measure the extent to which the amount of heat is dissipated, the temperature rise value of each part of the motor can be accurately detected to obtain the accumulated heat, thereby accurately obtaining the heat dissipation amount from the motor per unit time. And get an accurate temperature rise. Therefore, the total amount is accurately grasped by the input power Pin-output power Pout. If the amount of heat dissipated from the motor per unit time has been accurately detected, it is considered whether the total loss Ploss - the amount of heat dissipation Qf per unit time can be calculated by the subtractor 20. Accumulate the total loss, find the total heat of the motor, and calculate the temperature rise value. The temperature rise value at this time is a value relative to the ambient temperature of the motor. On the other hand, the amount of heat released from the motor per unit time varies with the temperature difference from the ambient temperature. The reason is that, in fact, the total loss Ploss input to the motor is not immediately lost by the heat dissipation amount Qf per unit time, but is subtracted from the electric quantity Ploss given in the calculation in the microcomputer. The heat dissipation amount Qf of the physical quantity of the natural world is simulated by the current value Pe of the total loss per unit time remaining in the motor. This is achieved based on the ambient temperature of the motor as a reference. The result is a negative feedback. Further, the overload determining circuit 43-1 of the first portion inputs the motor electric portion + the case temperature Tc1 (°C), compares it with the threshold value at which the motor case temperature becomes an overload, and when the threshold value is exceeded, the overload detecting signal is applied. Output to logic sum circuit 44. According to the above description, by the total loss current value Pe per unit time remaining in the motor, even if the applied load is used for the repeated load, the excessive calculation can be included, and the accumulated heat of the motor can be easily handled per unit time. The amount of heat dissipation and temperature rise. In Fig. 13, the heat dissipation characteristics of the motor casing are schematically represented. In this example, a method of measuring the total amount of heat released from the motor per unit time based on the test data is shown. The expression of the total heat dissipation amount includes the heat per unit time radiated from the cooling fins around the motor casing to the atmosphere, and the heat per unit time of the object side mounting base (fixing plate) from the base mounting portion where the motor is disposed. The heat per unit time is thermally transferred to the base side of the object side in contact with the flange surface when the motor is in the shape of a flange. The amount of heat refers to the total amount of heat dissipated per unit time as the total amount (total value). Also, the motor can be naturally cooled or forcedly cooled. The measurement of the heat dissipation characteristics of the motor casing is performed by confirming the installation conditions of the motor, etc., and the drive device (motor power conversion device 100) is combined with the motor and measured by a temperature rise test. The motor rotation speed and the load factor were changed, and the motor case temperature and the environmental temperature difference Tθ1 to Tθ3... shown by the x-axis in Fig. 13 were changed, and the temperature rise test was performed. Further, in the state of thermal equilibrium in which the temperature of the motor is saturated (the temperature rises and saturates, and the temperature is stabilized to a fixed temperature), the total loss Ploss applied to the motor is equal to the total heat dissipation amount Qf from the motor per unit time. Accordingly, the total heat dissipation amount Qf from the motor per unit time can be accurately obtained by measuring the total loss amount Ploss applied to the motor when the motor is in a thermal equilibrium state. For each output of the motor, the data of Figure 13 is pre-stored in non-volatile memory, whether the motor is forced air cooling or natural cooling, as long as there is data of both, it can be self-motor housing temperature and ambient temperature. The difference value Tθ(K) is read by reading the heat dissipation amount Qf per unit time. Returning to Fig. 1, the second to fourth portions will be described. For the second to fourth portions, the loss of each portion is input, and the heat is obtained from the loss, and the temperature rise value of each portion is calculated. In other words, the temperature rise of the stator winding is calculated for the second portion, and the temperature rise of the cage conductor or the strip rotor of the rotor is calculated for the third portion, and the temperature rise of the bearing is calculated for the fourth portion. Each of the overload determination circuits 43-2 to 43-4 compares the calculated temperature rise values with the second to fourth threshold values, and determines whether or not each portion is overloaded based on the threshold value. The logic circuit 44 constitutes an OR circuit, and when an overload output signal is transmitted from any of the four outputs including the first overload determination circuit 43-1, it is output to the protection processing circuit 18 as a motor overload detection signal OL. In Fig. 16, the contents of the loss calculation processing of the second to fourth portions are shown. In the figure, the classification column is divided into an induction motor and a permanent magnet type motor, and is divided into three parts, such as a stator, a rotor, and a bearing, as a part column, and the loss is divided into copper loss (primary copper loss, secondary copper loss). ), floating load loss, iron loss, and mechanical loss are all four types, and a loss operation processing content column is provided. Further, in this column, "A", "B", and "-" are described in the frame indicated by ○ in FIG. "A" is the part that is processed for each loss of each sampling operation. "B" is a table in which simulated or detailed test data is tabulated in advance, and the loss value is utilized from this condition. "-" is the part without corresponding loss. First, regarding the copper loss, it is "A", and each loss of the stator winding of the induction motor and the permanent magnet type motor, the cage conductor of the induction motor, or the strip rotor is calculated for each sampling, and Calculate (current squared) × (winding, or cage conductor resistance, or resistance of the end ring and strip conductor). Regarding "B", the iron loss is caused by the loss of the permanent magnet of the stator of the induction motor and the permanent magnet motor, the core of the rotor, and the permanent magnet type motor. For the iron loss, self-magnetic field analysis simulation and detailed test data, the iron loss data of each motor speed is tabulated, so the iron loss data is selected and input as the loss value according to the current time point. The mechanical loss is caused by the bearing and wind loss of the induction motor and the permanent magnet motor. The data of each speed of the motor is tabulated from the detailed test data, and the mechanical loss data of the speed at the current time point is selected and input as the loss value. For the floating load loss, the induction motor and the permanent magnet motor are selected based on the detailed test data to evaluate the total loss value, copper loss, iron loss, and mechanical loss, and the floating load loss with respect to the current value is tabulated. , input. Alternatively, it is calculated by floating load loss = total loss - (copper loss + iron loss + mechanical loss). Then, on the right side of the figure, there is a subtotal column E of the loss, and the stator of the induction motor calculates the subtotal Psi of each loss. This subtotal is the total loss Psi in the stator. The bearing and the like are the total loss Pbi of the sub-meter including the joint of the stator and the rotor, that is, the bearing including the bearing and the wind loss. Again, the rank of the rotor is the total loss Pri of the subtotal in the rotor. The i at the end of Psi, Pbi, and Pri represents an inductive motor (IM). Also, the total loss F line (Ploss) of the right row also represents an inductive motor. Returning again to Fig. 1, the ratio of the blocks 41-2, 41-3, 41-4 represented by k2, k3, k4 with respect to the total loss is shown in the rightmost row E/F of Fig. 16. It is calculated by k2=Psi/(Ploss)i, k3=Pri/(Ploss)i, and k4=Pbi/(Ploss)i. Regarding this ratio k2, k3, k4 with respect to the total loss, it is important to recalculate the ratio for each sample. The reason for this is that the type of loss generated by the motor varies depending on the rotational speed and torque of the motor. Furthermore, the total loss (Ploss) i is the same as that calculated by Pin-Pout (Expression 2), and the purpose is to distinguish between two types of motors. In the permanent magnet type motor, P at the end of the loss (PM) is denoted by Psp, Pbp, Prp, and (Ploss)p. Further, since the loss calculation processing of the permanent magnet type motor is the same as that of the induction type motor, description thereof will be omitted, but the rotor side is not a cage conductor, and therefore there is no copper loss. Further, regarding the masses of the transfer functions of the motor heat accumulating portion 42-1, the stator 42-2, the rotor 42-3, and the bearing 42-4, m1 is input: motor mass, m2: mass of the stator, m3: mass of the rotor, m4 : The quality of the bearing. Then, regarding the specific heat, the equivalent specific heat of the input motor or each part. Regarding the equivalent specific heat, when performing detailed tests in the factory, one point is set one by one at each rated point and rated torque as a measurement point for measuring the temperature in the temperature rise test. The temperature rise test measures the total loss Ploss and the temperature rise value at a rated point (rated speed, rated torque) at a specific measurement point. The mass used above is m1 to m4. Further, the equivalent specific heat c1 of the motor electric unit + the casing is obtained from the value obtained by the specific heat measurement test by the formula (Expression 12). The equivalent specific heat c2 of the stator winding, the equivalent specific heat c3 of the rotor cage conductor, and the equivalent specific heat c4 of the bearing are also calculated by the specific heat measurement test. The equivalent specific heat constant is registered in the memory as a motor constant, and is used when calculating the motor case temperature Tc1, the stator winding temperature Tc2, the cage conductor temperature Tc3, and the bearing temperature Tc4. Here, when the losses input to the stator 42-2, the rotor 42-3, and the bearing 42-4 are collectively referred to as symbols Plo2, Plo3, and Plo4, (Expression 18). [Expression 18] (Expression 18) Plo2=Psi×(Ploss-Qf)/(Ploss)i=k2×Pe... Loss of the second part Current value Plo3=Pri×(Ploss-Qf)/(Ploss)i =k3×Pe... loss of the third part current value Plo4=Pbi×(Ploss-Qf)/(Ploss)i=k4×Pe... loss of the fourth part current value here, Psi: the total loss included Loss of the second part (stator) (W) Pri: loss of the third part (rotor) included in the total loss (W) Pbi: loss of the fourth part (bearing, etc.) included in the total loss (W) k2 : ratio of loss of the second part to total loss (=Psi/(Ploss)i) k3: ratio of loss of the third part to total loss (=Pri/(Ploss)i) k4: loss of the fourth part Ratio with respect to total loss (= Pbi / (Ploss) i) Pe: total loss current value (= Ploss - Qf) As a result, regarding the stator windings output to the stator 42-2, the rotor 42-3, and the bearing 42-4 When the total temperature of the stator is Q2, the temperature rise value Tc2 (K) is set to (Expression 14). When the total heat of the rotor cage conductor or the strip rotor is Q3, the temperature rise value Tc3 (K) of the rotor cage conductor or the strip rotor becomes (Expression 15). When the total heat of the bearing in the bearing or the like is set to Q4, the temperature rise value Tc4 (K) of the bearing in the bearing or the like is (Expression 16). Here, the temperature rise values Tc2 to Tc4 (K) are supplied with the ambient temperature Ta (°C) of the motor, and are supplied as the temperatures Tc2 to Tc4 (°C) of the respective portions. Then, the temperature calculated for each of the second to fourth portions is an overload determination circuit 43-2 to 43-4 for each of the portions that are compared with each of the second to fourth threshold values determined to be overloaded. On the other hand, when the threshold value is exceeded, the four overload detection signals including the first overload determination circuit 43-1 are output to the logic sum circuit 44 when the threshold value is exceeded. A 4-input OR circuit is constructed in the logic sum circuit 44, and when either of them transmits the overload output signal, it is output to the protection processing circuit 18 as the motor overload detection signal OL. According to the above description, in addition to the total loss that can be accurately obtained, the loss of the motor can be accurately accumulated in each part depending on the number of revolutions and the load rate. Therefore, it is possible to perform overload detection for each part one by one. Therefore, even if a repeated load is used, the overload detection signal of the motor can be outputted as a part that has previously become an overload. The protection processing circuit 18 displays and reports the overload information to the outside, and stops the motor to perform overload protection of the motor. Fig. 12 is a view for explaining an overload detecting circuit to which a permanent magnet type motor according to an embodiment of the present invention is applied. The configuration is the same as that of FIG. 1, and the description thereof is omitted. However, FIG. 1 is an induction motor, and FIG. 12 is a permanent magnet type motor. Therefore, the third portion is a cage conductor of the rotor in FIG. 1, and FIG. Permanent magnet of the rotor. When the loss of the stator 42-2, the rotor 42-3, and the bearing 42-4 input to the permanent magnet type motor is collectively referred to as symbols Plo2, Plo3, and Plo4, it becomes (Expression 19). [Expression 19] (Expression 19) Plo2=Psp×(Ploss-Qf)/(Ploss)p=k2×Pe... Loss of the second part Current value Plo3=Prp×(Ploss-Qf)/(Ploss)p =k3×Pe... loss of the third part current value Plo4=Pbp×(Ploss-Qf)/(Ploss)p=k4×Pe... loss of the fourth part current value here, Psp: the total loss included Loss of the second part (stator) (W) Prp: loss of the third part (rotor) included in the total loss (W) Pbp: loss of the fourth part (bearing, etc.) included in the total loss (W) k2 : ratio of loss at the second portion to total loss (= Psp / (Ploss) p) k3: ratio of loss at the third portion to total loss (= Prp / (Ploss) p) k4: loss at the fourth portion Ratio to total loss (=Pbp/(Ploss)p) Pe: Total loss current value (=Ploss-Qf) Further, if the total heat of the permanent magnet is set to Q3, the rotor of the permanent magnet motor is permanent The temperature rise value Tc3 (K) of the magnet is (Expression 15). Here, similarly, the temperature rise value Tc3 (K) is added to the ambient temperature Ta (° C.) of the motor as the temperature Tc3 (° C.) of each part. 14A to 14C are views for explaining an equivalent circuit of an induction type motor. Figure 14A shows the circuit of an inductive motor in operation. The resistance and leakage reactance of one phase of the stator (primary) winding are represented by r1 (Ω) and x1 (Ω), and the excitation conductance and the magnetizing susceptance are represented by g0 and b0. If the voltage E1 is applied to the primary winding of the transformer of the equivalent circuit, the secondary winding senses the voltage E22. The secondary resistance and the leakage reactance are set to r22 (Ω) and X22 (Ω), and the mechanical resistance is represented by the load resistor r'. The phase voltage of one phase of the motor is set to V1, and the primary current I1 flows, and the exciting current I0 flows through the exciting circuits g0 and b0 to flow I1' on the primary side of the transformer. Further, the current I22 flows through the secondary side. Fig. 14B shows an equivalent circuit in which the amount of the secondary side circuit of Fig. 14A is converted to the primary side, and the circuit of Fig. 14B is usually used. Further, when the primary impedance caused by the exciting current can be ignored, the equivalent circuit becomes Fig. 14C. Here, in the equivalent circuit diagram 14B, the copper loss of the inductive motor includes primary copper loss and secondary copper loss. If the number of phases of the primary and secondary windings of the motor is m1 and m2, the primary copper loss is m1 × (I1) ² ×r1, the secondary copper loss is m2×(I1') ² ×r2. The motor constant, the rated current If, and the no-load (excitation) current I0 are confirmed by detailed tests, and are stored in the non-volatile memory mounted on the control circuit 15 of the motor power conversion circuit, and are executed by the CPU and the DSP. Operation processing. Moreover, the motor current is detected by the U-phase and W-phase current detectors CTu12 and CTw13 of FIG. 9, and the current I1' vector for calculating the secondary copper loss can be subtracted from the primary current vector I1 without load (excitation). The current vector I0 is obtained. Fig. 15 is a view for explaining the graph of the motor iron loss data after the table in the embodiment. The iron loss does not change due to the increase or decrease of the load. The iron loss of the motor includes hysteresis loss and eddy current loss, and the relationship is expressed in (Expression 3) and (Expression 4). Further, in the motor power conversion device, since the carrier frequency generated by the PWM waveform is a high frequency component of several k to several tens of kHz, iron loss due to the PWM carrier frequency is also generated. Since it is difficult to directly measure the iron loss power, the iron loss with respect to the rotational speed is previously tabulated based on the magnetic field analysis simulation and the data of the combined temperature rise test of the motor and the drive device (motor power conversion device) before the product is shipped. Figure 15 is a graph showing the graph of motor iron loss data after tabulation. 1 denotes a hysteresis loss Ph which increases in proportion to the motor rotation speed, 2 denotes an eddy current loss Pe which is proportional to the square of the motor rotation speed, and 3 denotes an iron loss caused by a PWM drive of the fixed carrier frequency (by carrier frequency The resulting hysteresis loss + subtotal of eddy current loss due to carrier frequency). In addition, the total iron loss obtained by the total of 1 to 3 is Pfe and is indicated by a solid line. Further, in the magnetic field analysis simulation, the iron loss total value Pfe is divided into a stator and a rotor, and is divided into a stator side iron loss Pfes and a rotor side iron loss Pfer. The purpose of dividing the iron loss is to separately calculate the temperature of the portion on the stator side and the temperature of the portion on the rotor side, which have been previously described by the table of Fig. 16. The iron loss on the stator side and the rotor side is based on the number of revolutions at the current time point, and the iron loss value is updated one by one for each sample by referring to the table. Fig. 17 is a view for explaining an overload display, notification, and alarm output circuit of the embodiment. Fig. 17 is a schematic diagram showing the overall circuit of the inductive or permanent magnet type motor power conversion device, and the control logic circuit 15 shown in Fig. 10, showing a partial overload output circuit of the hardware. In the control logic circuit 15, a digital operator 59 is externally provided from the CPU 53 via a communication connector (CN1) 58. Five input keys 63 are arranged below the display 60 of the digital operator 59. A speaker 61 is disposed on the upper right side, and an illuminator 62 is disposed below. In the digital operator 59, the content of the overload detection is displayed or reported by the illuminator 62, the display 60, and the speaker 61, thereby notifying that there is an overload alarm occurring nearby. Furthermore, the overload alarm has an overload detection and protection. The result of the autonomous circuit blocking the motor informs the surrounding effect. Further, the control logic circuit 15 has a configuration in which the inverter 53 is connected from the relay coil 55 and the relay contact 57 via the external terminal to the external output device 64 via the inverter terminal 55 to warn of an overload state or an alarm. It is reported that the protection of the autonomous circuit blocks the motor. Fig. 18 is a view for explaining the contents of the overload display, the notification, and the alarm output of the present embodiment. "1" is the overload display, "2" is the overload notification, and "3" is the overload alarm. The right-hand side line defines the disposal of the main circuit power supply for overload detection. The overload display and overload notification of "1" and "2" are that even if the overload detection is performed, the main circuit power supply is still in the supply state and the motor is not immediately protected. Run, let the surrounding operators prepare for stopping the motor. This is because if the motor is suddenly stopped, for example, a defective product is caused in the product in the supply material. Therefore, the motor is stopped after the supply of the material is stopped, or the motor is stopped after the completion of processing of one product. The overload warning of "3" is that the motor power conversion device 100 itself immediately blocks the main circuit power from the motor to implement the overload protection of the motor, so that the motor stops by itself, and the alarm is performed afterwards. In the digital operator column, the illuminator 62 notifies the overloaded display by visual observation, and the speaker 61 emits a loud sound such as a sound effect, a voice, a sound, a buzzer sound, and the like to notify the person. Furthermore, FIG. 18 shows the general case, and there are cases in which it differs depending on the surrounding environment, so care must be taken. The display 60 of the digital operator is an accurate display of the contents by the characters, and is not used for the attention of the surrounding workers to immediately and actively attract the attention of the operator, and is therefore referred to as Δ. Then, the external terminal outputs the overload display of the TM1, TM2 systems 1, 2, the overload notification is used for the warning contact output of the warning, and the overload alarm of 3 is used for the contact output of the report after the alarm is blocked. The overload display, overload notification, and overload alarm can be selected by the user by parameters. Fig. 19 is a schematic view for explaining an environmental thermometer which detects the ambient temperature of the motor of the embodiment. The figure shows the case where the ambient temperature of the motor 1 is detected by the environmental thermometer 52 and input to the motor power conversion device 100. The signal of the encoder 14 of the motor output shaft is captured to the motor power conversion device 100, and the speed command N is input from the upper control device 51. The operation start is to turn on the control circuit power supply 50, and secondly, the AC main circuit power supply 2 is turned on, and then the speed command N is input from the upper control device 51 to start the operation. Furthermore, the motor power conversion device 100 operates the maximum temperature of the ambient temperature range of the motor to be the ambient temperature without detecting the ambient temperature of the motor by the ambient thermometer 52. 20A and 20B are diagrams for explaining a threshold value at which the second-part stator winding of the present embodiment is determined to be overloaded. First, the case where the ambient temperature Ta of the motor is not detected in Fig. 20A will be described. (a) indicates the heat resistance levels A to H of the motor, and the maximum allowable temperature of each level corresponds to (b). For example, in level A, the maximum allowable temperature is 105 ° C, and the higher the level H, the closer to 180 ° C, which is determined by the specifications. Here, the method of measuring the temperature of the stator winding of the motor has an electric resistance method. The electric resistance method uses a method in which the temperature coefficient of resistance is known, and the temperature rise value is calculated from the resistance value before and after the temperature test, and the average temperature of the winding can be measured. However, the temperature difference between the portion affected by the cooling wind and the portion not affected by the one winding cannot be measured by the resistance method. Therefore, the margin δ of the margin temperature is set in advance, and as shown in (c), the margin of the (maximum allowable temperature - δ) is observed. Further, the second threshold value is selected in accordance with the level of the winding itself, the level of the insulating paper of the protective winding, and the level of the motor such as the level of the varnish material for ensuring the insulation life. Further, the tolerance δ of the winding is generally set to 5 to 15 ° C, and it is finally confirmed by actual measurement in a temperature test using a thermocouple or the like. (d) shows the allowable temperature rise value of the motor stator winding that becomes the second threshold. When the ambient temperature Ta of the motor 1 is not detected, the initial value of the ambient temperature Ta of the motor is set to the upper limit value Ta(max) of the operating temperature range of the motor. For example, if the upper limit value Ta(max) is 40 ° C, the initial value is set to 40 ° C. If the actual ambient temperature here is 10 ° C, since the control starts from 40 ° C, the deviation from the actual temperature is +30 (K), and there is a gap between the two. In (c), the value obtained by subtracting the tolerance from the maximum allowable temperature is indicated. Therefore, when the actual ambient temperature is 10 ° C, the overload protection open circuit operates at a temperature lower by 30 (K). Although it seems that the AC motor 1 still has a margin, it can be considered that the overload protection circuit is started too early, but when the actual ambient temperature is not detected, it is better to set the stricter from the viewpoint of preventing the burning accident. The condition (in this case, the most stringent condition is the initial value of 40 ° C). As described above, the allowable temperature rise value of the motor stator winding which is the second threshold value of (d) is a value obtained by subtracting Ta (max) from the value of (c) after the tolerance is subtracted. Next, the case of detecting the ambient temperature Ta of the motor of Fig. 20B will be described. (a) to (c) of Fig. 20B are the same as (1). In the case of Fig. 20B, the actual ambient temperature of the AC motor 1 can be detected. Thereby, the allowable temperature rise value (d) of the motor stator winding as the second threshold value is expressed by (Expression 20). [Expression 20] (Expression 20) Second threshold = {(maximum allowable temperature) - δ - Ta(max)} + {Ta(max) - Ta} (K) = (maximum allowable temperature) - δ - Ta Among them, the second threshold: the allowable temperature rise value of the motor stator winding (K) The maximum allowable temperature: the maximum allowable temperature of the motor's heat resistance level (°C) δ: the tolerance (= 5 to 15 ° C) Ta (max): motor use Upper limit of temperature range (°C) Ta: Ambient temperature of the motor obtained by measurement (°C) When the ambient temperature is lower than the upper limit of the operating temperature range of the AC motor 1, the stator winding temperature is limited to the upper limit. It can be increased according to the difference between them, and the overload protection breaking action will start according to the actual conditions with appropriate conditions. Conversely, when the ambient temperature is higher than the upper limit of the operating temperature range of the AC motor 1, the second threshold is lowered, so that the motor does not burn. Therefore, a more accurate overload protection alarm can be realized. Further, in (Expression 13) and (Expression 14), the temperatures of the motor case and the motor stator winding are shown. If the total loss of the motor and the loss of the stator side are affected, considering the difference between the motor housing and the stator winding (mass × specific heat), the mass of the motor housing is large, and the stator winding is extremely small, and the difference between the two is significant. . Accordingly, the temperature of the stator winding is highly sensitive and reacts violently to the variation of the loss, so that the effect of improving the accuracy of the overload protection breaking operation can be obtained, and the motor temperature management closer to reality can be realized. Further, in the setting of the second threshold value, the environmental temperature of the motor is made to correspond to both the fixed value and the ambient temperature value, and the overload protection disconnection operation is performed at a temperature suitable for maintenance and efficient use of the AC motor 1. Fig. 21 is a view for explaining the hysteresis of the overload detection signal of the present embodiment. The previous overload protection system uses an electronic thermal protector to detect the motor current current square time accumulation mode. When the accumulated value obtained by the counter reaches the overload threshold, the overload detection signal is output, and the power transmission to the motor is stopped. The action of the overload detection circuit ends at the point in time. In the present embodiment, even if the power transmission to the motor is stopped after the overload detection is performed, as long as the control circuit power supply continues to be energized, the heat dissipation calculation of the motor can be continued accurately as in the running state. Therefore, by setting the overload release temperature of the motor, as long as the motor is cooled to the recovery temperature, the main circuit can be turned on, and the temperature of the motor can be re-operated while continuing to the heat storage operation from the middle of the heat dissipation. The automatic recovery function is not used when the overload display output of 1 or the overload notification output of 2 described in FIG. 18 is selected by the parameter, and is used for detecting the necessary function of continuing operation after the overload, but When the parameter selects the overload alarm of 3, it is used to block the main circuit power when the overload is detected. As a specific action, the gate signals of all the switching elements 10 of the inverter 9 are continuously turned off until the motor cools down to the overload release temperature. Here, if the automatic recovery is selected by the setting parameter in advance, even if there is no external alarm reset input, as long as the temperature reaches below the overload release temperature of the motor, the gate signal of all the switching elements 10 of the inverter 9 is turned off. The TM1 and TM2 outputs are output from the external terminal to cancel the report output of the alarm block, so the operation can be restarted from the contact output. For example, in a robot motor that operates in an unmanned factory, once stopped due to detection of an overload, the stop state is maintained until the maintenance worker comes next time, but with the hysteresis in the overload detection signal of FIG. The overload release function, the operation can be restarted and automatically restored. In the figure, the temperature Tcn of each part is marked on the x-axis (Tc1~Tc4 in Fig. 1 and Fig. 12), and the y-axis overload detection signal is L level in the normal state and H in the overload state. Level. The threshold is in an overload state at the overload detection temperature TcnH. If the motor cools down to the overload release temperature TcnL, the operation will start as soon as the operating parameters are automatically restored. In the case of manual recovery, the operator temporarily resets and then starts the operation by starting the run button. This hysteresis is set at each location, so it will only operate if it is lowered to a safe temperature. Fig. 22 is a view for explaining an example of a temperature rise test when a repeated load is applied in the embodiment. The x-axis represents time, and the y-axis represents the motor case temperature, the stator winding temperature, and the temperature of the rotor cage conductor by the temperature rise of each part. The motor-based induction motor is ventilated and cooled at a fixed speed by means of a separate cooling fan. The load is applied with repeated loads and the speed command is entered into the speed command of Figure 5. The effective torque of one cycle of the motor is applied 100%, so that the load applied to the motor exceeds the rated torque. In the figure, the motor housing is forced to cool directly by a separate cooling fan, so the temperature rises slowly. Since the motor housing is being cooled, the temperature of the stator winding rises in a suppressed state. However, the cage conductor of the rotor is located at the center of the motor, and the cooling efficiency is poor, so the temperature continues to rise sharply. As a result, the rotor cage conductor of the third portion of the present embodiment is detected to be overloaded at time t0, thereby forming an overload trip of the motor to protect the motor from being burnt. In the overload protection detection only by the current detection of the stator winding, after the time t0, the stator winding will rise to the overload protection level, and in this case, the rotor side cage conductor will be burnt. Therefore, in order to perform the overload operation before the overload detection time t0, it is always necessary to reduce the threshold value and take a realistic response. As a result, since the overload protection time is advanced in advance, the pre-protection is started in the same manner as in the case of the fixed load used for the non-repetitive load. Fig. 23 is a view for explaining the automatic recovery operation after the overload detection of the embodiment. The system monitors the temperature of each part when the load is applied to the induction motor, the external terminal output (TM1, TM2), the external main circuit power supply, and the control circuit power supply. The temperature measurement position is the motor case temperature Tc1 of the first portion, the stator winding temperature Tc2 of the second portion, the rotor cage conductor temperature Tc3 of the third portion, and the bearing temperature Tc4 of the fourth portion. The parameter is set to automatically restore the selection. First, starting from time 0, the rotor cage conductor temperature Tc3 of the third portion at time t0 reaches the overload detection temperature Tc3H, and an overload is detected, and the gate signals of all the switching elements 10 of the inverter 9 are turned off. Further, it is indicated that the external terminal output (TM1, TM2) is output and the main circuit power supply is blocked externally. In this state, the overload detecting circuit 17a also continues the arithmetic operation, and therefore the temperatures Tc1 to Tc4 of the respective portions are lowered while continuing to radiate heat. Then, at time t1, the rotor cage conductor temperature Tc3 is lowered to the overload release temperature Tc3L, so that the gate signal of the switching element 10 is turned off, and the external terminal outputs (TM1, TM2) are turned off. The AC main circuit power is turned on again by the external terminal output, and the speed command is given from the upper device, whereby the operation is restarted. Further, the temperatures Tc1 to Tc4 of the respective portions are continued to the temperature at the time point t1 and the temperature is increased. Figure 24 is a diagram for explaining the transmission of data for tracking the temperatures of various parts of a plurality of motors. By the overload detecting circuits 17a and 17b of the inductive or permanent magnet type motor, the motor case temperature Tc1 of the first portion calculated for each part of the motor, the stator winding temperature Tc2 of the second portion, and the third portion can be used. The rotor cage conductor temperature Tc3 and the fourth portion bearing temperature Tc4 are displayed on the external PC screen as shown in the tracking screen shown in FIG. Here, the tracking data transmission during the automatic recovery operation after the overload detection shown in FIG. 23 will be described. The CPU 53 in the control logic circuit 15 has a communication port capable of serial communication. In Fig. 17, the case where the communication port is used to communicate with the digital operator 59 has been described. Further, a RAM (Random Access Memory) memory 65 is connected to the CPU 53, and the CPU 53 is responsible for the calculation of the temperatures Tc1 to Tc4 of the respective parts. First, before the motor is operated, the personal computer 66 is used to select the measurement point to be tracked, the start trigger signal, and the measurement point of the I/O (Input/Output) signal, from the personal computer to the motor power conversion device 51. The CPU 53 sends a message that it is ready to track the data. Then, the operation operator starts the signal and operates the motor, and performs the operation of FIG. 23, and tracks at intervals of a fixed time. The CPU 53 saves the data to the RAM 65 and ends the tracking to stop the motor. When the tracking is completed, the CPU 53 automatically serially communicates the tracking data from the RAM 65 to the personal computer 66, and displays the tracking screen on the personal computer side as shown in FIG. The overload detection temperature TcnH and the overload release temperature TcnL of the temperatures Tc1 to Tc4 of the respective parts are displayed in different colors on the tracking screen, so that the operator can instantaneously determine whether or not there is a margin in the temperature of each part of the motor. As described above, according to the present embodiment, since the overload state of the motor is managed based on the heat of each of the stator, the rotor, and the bearing constituting the motor, the accuracy of the overload protection is improved. In particular, the motor is different in heat generation mode depending on the relationship between the number of revolutions, the number of revolutions, and the torque, and based on this point, the configuration of monitoring the heat for each motor element in the present embodiment can make the overload protection management have Significant versatility. In addition, by arranging the value of each element of the motor from the calculation using the software and the arithmetic unit, the motor can be easily managed without the assembly load and the failure of the sensor such as an electronic thermal protector. Heat. While the embodiments of the present invention have been described above, the present invention is not limited to the above-described configurations, and various modifications can be made without departing from the spirit and scope of the invention.

1‧‧‧Motor
1a‧‧‧Induction motor
1b‧‧‧ permanent magnet motor
2‧‧‧AC main circuit power supply
3‧‧‧DC power supply
4‧‧‧Shunner with power regeneration function
5‧‧‧Full-wave rectification converter
6‧‧‧Power regeneration converter
7‧‧‧Regeneration AC reactor
8‧‧‧Ring Capacitor
9‧‧‧Inverter
10‧‧‧Switching elements
11‧‧‧Continuous current diode
12‧‧‧U phase current detector CTu
13‧‧‧W phase current detector CTw
14‧‧‧Encoder
14a‧‧‧Encoder for position and speed detector
14b‧‧‧Encoder for position, speed and magnetic pole position detector
15‧‧‧Control logic
16‧‧‧ total loss computing circuit
17‧‧‧Overload detection circuit
17a‧‧‧Induction motor overload detection circuit
17b‧‧‧Overload detection circuit for permanent magnet motor
18‧‧‧Protection processing circuit
19‧‧‧Adder
20‧‧‧Subtractor
21‧‧‧Speed Controller (ASR)
22‧‧‧d-axis current controller (ACR)
23‧‧‧q-axis current controller (ACR)
24‧‧‧dq/3-phase converter
25‧‧‧PWM circuit
26‧‧‧3 phase/dq converter
27‧‧‧ Position, speed calculator
28‧‧‧ Position, speed, magnetic pole position calculator
29‧‧‧Magnetic Operator
30‧‧‧Sliding frequency calculator
31‧‧‧Angle frequency conversion constant
32‧‧‧Torque Operator
33‧‧‧ Output Pout Operator
34‧‧‧current calculator
35‧‧‧Input Pin Operator
36‧‧‧ integrator
37‧‧‧Part 1 (Motor Electrical Department + Housing)
40‧‧‧Transfer function of the motor heat sink
41-2‧‧‧ ratio to total loss
41-3‧‧‧ ratio to total loss
41-4‧‧‧ ratio to total loss
42-1‧‧‧Transfer function of motor regenerator
42-2‧‧‧Transfer function of the stator
42-3‧‧‧Rotor transfer function
42-4‧‧‧Transfer transfer function
43-1‧‧‧1st part overload determination circuit
43-2‧‧‧The second part of the overload determination circuit
43-3‧‧‧3rd part overload determination circuit
43-4‧‧‧Overload determination circuit for the fourth part
44‧‧‧Logic and circuit
45‧‧‧Filter circuit
46‧‧‧Reversing circuit
47‧‧‧Multiplier
48‧‧‧3 input adder
49‧‧‧Motor power conversion device
50‧‧‧Control circuit power supply
51‧‧‧Upper control device
52‧‧‧Environmental Thermometer
53‧‧‧CPU
54‧‧‧Inverter gate
55‧‧‧Relay coil
56‧‧‧ diode
57‧‧‧Relay contacts
58‧‧‧Communication connector
59‧‧‧Digital Operator
60‧‧‧ display
61‧‧‧Speakers
62‧‧‧ illuminator
63‧‧‧Enter key
64‧‧‧External output device
65‧‧‧RAM memory
66‧‧‧Personal Computer
100‧‧‧Motor power conversion device
Ratio of k2‧‧‧ relative to total loss
Ratio of k3‧‧‧ relative to total loss
Ratio of k4‧‧‧ relative to total loss
CN1‧‧‧Communication connector
OL‧‧‧Overload detection signal
OR‧‧‧ circuit
TM1‧‧‧External terminal output
TM2‧‧‧ External terminal output

Fig. 1 is a block diagram schematically showing an overload detecting circuit when a motor control device according to an embodiment of the present invention is applied to an induction motor. Fig. 2 is a schematic view showing the motor loss at the time of power running of the motor control device of the embodiment. Fig. 3 is a schematic view showing the motor loss at the time of regeneration of the motor control device of the embodiment. Fig. 4 is a schematic view showing the motor loss when the motor control device of the present embodiment is regenerated by the DC power supply. Fig. 5 is a view showing an example of the use of the repeated load in the relationship between the number of revolutions and the torque of the motor for the press. Fig. 6 is a schematic view showing the loss in relation to the motor rotation speed-torque characteristic at the time of power running of the motor control device of the embodiment. Fig. 7 is a schematic diagram showing the loss in relation to the motor rotation speed-torque characteristic at the time of regeneration of the motor control device of the embodiment. Fig. 8 is a view showing the types of loss generated in each part of the motor. Fig. 9 is a block diagram schematically showing the overall circuit in the case where the motor control device of the present embodiment is applied to an induction type motor. Fig. 10 is a block diagram schematically showing the overall circuit when the motor control device of the embodiment is applied to a permanent magnet type motor. Fig. 11 is a schematic view showing another configuration and a processing example of the input power detecting processing unit of the embodiment. Fig. 12 is a block diagram schematically showing an overload detecting circuit in the case where the motor control device of the present embodiment is applied to a permanent magnet type motor. Fig. 13 is a view showing the heat dissipation characteristics of the motor case. 14A to 14C are views showing an equivalent circuit of an induction type motor. Fig. 15 is a view showing the motor iron loss data after the table of the motor control device of the embodiment. Fig. 16 is a view showing the contents of the loss calculation processing of each part of the motor. Fig. 17 is a block diagram showing the overload display, notification, and alarm output circuit of the embodiment. Fig. 18 is a view showing the contents of the overload display, the notification, and the alarm output in the present embodiment. Fig. 19 is a block diagram showing the configuration of an environmental thermometer which detects the ambient temperature of the motor of the embodiment. 20A and 20B are views showing a threshold value at which the motor control device of the present embodiment determines that the second-part stator winding is overloaded. Fig. 21 is a view showing the hysteresis of the overload detection signal of this embodiment. Fig. 22 is a view showing an example of a temperature rise test when a repeated load is applied in the embodiment. Fig. 23 is a view showing the flow of control at the time of performing the automatic recovery operation after the overload detection of the present embodiment. Fig. 24 is a schematic view showing a data transmission configuration for tracking the temperatures of the respective portions of the plurality of motors of the present embodiment.

Claims (12)

A motor control device having a control unit that detects a total loss between an input power and an output power of an AC motor, and obtains a total deviation between the total loss and a total heat dissipation amount per unit time of the AC motor. Calculating the temperature of the AC motor based on the heat, determining the overload of the AC motor based on the temperature, and the control unit calculates the stator winding temperature from the heat of the stator of the AC motor, and calculates the heat from the rotor of the AC motor. The rotor temperature is compared with a corresponding threshold value, and when at least one of the threshold values is reached, the AC motor is overloaded to perform an output of the external notification signal and at least one of the reduction or the stop of the power supply of the AC motor. And the heat of the rotor includes the heat of the conductor or the magnet. The motor control device according to claim 1, wherein the control unit further calculates a temperature of the other component from heat of at least another component of the AC motor, and when the temperature reaches a corresponding threshold value, The AC motor is overloaded to perform at least one of an output of an external notification signal and a decrease or a stop of power supply of the AC motor. The motor control device of claim 1 or 2, wherein said control unit subtracts said AC motor from said stator winding temperature and said rotor temperature The temperature obtained at ambient temperature is compared to the above threshold. The motor control device according to claim 1 or 2, wherein the control unit multiplies the heat obtained by the deviation from the total heat radiation amount per unit time of the AC motor by the stator winding, the rotor, and the other component Calculate the respective heat by the ratio of the corresponding losses. The motor control device according to claim 4, wherein the ratio of the loss corresponding to each of the above is obtained by dividing the total loss of the stator winding, the rotor, and the other constituent elements by the total loss of the AC motor. The motor control device of claim 5, wherein the ratio of the respective losses corresponding to the above is calculated for a specific sampling period for each of the losses of the AC motor. The motor control device according to claim 1 or 2, wherein the control unit divides a temperature rise value of the stator winding, a temperature rise value of the rotor, and a temperature rise value of the other component by a respective heat amount Calculated by multiplying the respective mass by the value obtained by the equivalent specific heat. The motor control device of claim 1, wherein The threshold value is a temperature value obtained by subtracting the upper limit value of the operating temperature range of the AC motor from the highest allowable temperature value of the heat resistance level of the AC motor. The motor control device of claim 8, wherein the control unit further receives an ambient temperature value of the AC motor, and the threshold value is obtained by subtracting a upper limit value of a temperature range of the AC motor from the maximum allowable temperature value. The temperature value is obtained by adding the temperature value obtained by subtracting the above ambient temperature value from the upper limit value. The motor control device according to claim 8 or 9, wherein the control unit stores the tolerance temperature value in advance, and the threshold value is obtained by subtracting the tolerance temperature value from the highest allowable temperature value. The motor control device according to claim 1 or 2, wherein the control unit further stores an overload release temperature value of the AC motor, and performs at least one of reducing or stopping the power supply of the AC motor due to an overload, according to at least one of The above-described overload release temperature value performs the recovery of the power supply described above. The motor control device of claim 11, wherein the control unit receives or resets the set value of the power supply when the overload condition is received via the input member, and When the set value is a decrease or a stop of the set value of the power supply, the power supply is restored based on the overload release temperature value.