JP5034282B2 - Inductive load drive controller - Google Patents

Description

  The present invention relates to a drive control device for driving an inductive load such as an electromagnetic actuator having a winding, an electromagnet, and a servo motor, and more particularly to an inductivity such as an electromagnetic actuator capable of protecting from overload and detecting an abnormality of the winding. The present invention relates to a load drive control device.

As a drive control device for an electromagnetic actuator, there is a servo amplifier or the like. As a load protection function in this drive control device, a load is generally protected from overheating by a thermal relay. However, after restarting in a short time after the overload protection operation, the load temperature rises again without being sufficiently lowered and may be overheated, resulting in poor insulation or burning of the load windings. . The thermal relay could not protect in the case of restart after such a short time.
On the other hand, based on the temperature signal that detects the temperature of the winding of the motor and the current signal from the current detector, the current of the switching element of the inverter device is limited when each exceeds a set value. (For example, refer patent document 1).
Also, the calorific value of the servo motor is calculated using the current value flowing through the servo motor, the motor temperature is calculated by applying a thermal model based on the thermal resistance and heat capacity of the motor, and the motor temperature exceeds the set temperature. In some cases, the output of the drive control device is stopped when the time exceeds a certain time (see, for example, Patent Document 2).
In some cases, the current and voltage of the load are detected, and when the electric power exceeds a certain reference value, the switching means is opened to cut off the current (for example, see Patent Document 3).

FIG. 6 is a circuit diagram showing overload protection described in Patent Document 3. In FIG. In the figure, 61 is a load control device, and a main circuit 64 is formed between a three-phase power source bus 62 and each phase winding terminal of a three-phase induction motor 63 as a load. Are a circuit breaker 65 for wiring, an opening / closing means 66, a current detection means 67, and a zero-phase current transformer 68 in this order from the power supply bus 62 side. The circuit breaker 65 for wiring is opened when an excessive current flows to disconnect the main circuit 64 from the power supply bus 62. A main contact 66a of an electromagnetic contactor 66 is interposed on the load side of the circuit breaker 65 for wiring. The main contact 66a is closed by energizing the exciting coil 66b, and is opened by de-energizing the exciting coil 66b. 75 is a voltage detection circuit, and 76 is a current detection circuit. When the current and voltage of the load 63 are detected by the voltage detection circuit 75 and the current detection circuit 76 and input to the control circuit 77 to calculate the power and others, and when the load current and power exceed a certain reference value When these time integration values reach a limit value or when a predetermined delay time elapses, the switching means is opened to interrupt the current.
Japanese Patent Application Laid-Open No. 11-381884 Japanese Patent No. 2745166 JP 2001-281275 A

However, in the overload protection method of Patent Document 1, protection from overheating is possible by detecting the temperature of the electric motor with a temperature detector, but the addition of the temperature detector is necessary, and the device is complicated. There was a problem.
Further, the overload protection method disclosed in Patent Document 2 does not require a temperature detector, but has a problem in that computation using a thermal model is complicated and a large processing capacity is required.
In addition, each method has a problem that it is necessary to reset the overload protection detection condition when the load cooling condition changes, and abnormalities such as partial short-circuiting of the load winding cannot be detected. .
Further, in the invention described in Patent Document 3, when the overload protection operation is performed once and restarted after a short time, the temperature of the load rises without being sufficiently lowered, resulting in poor insulation and burnout of the winding of the load. There was a problem.
The present invention has been made in view of such problems, and it is possible to detect an overload abnormality with a simple configuration with high reliability, and to detect an abnormality in the winding of the load, and an inductive load such as an actuator. An object is to provide a drive control device.

（ここで、Tはサンプリング周期、時刻ｔ＝kT時点（但しk=1,2,・・・,N）、Va(k)，Ia(k)，およびdP/dt(k)はkT時点の巻き線の各電圧、電流、および速度、Lは前記巻き線のインダクタンス、Keは誘起電圧定数で、誘起電圧eM(k)=Ke・dP/dt(k)である。）
それらの値の時間的変化に一定値以上の増（＋）減（−）があるとき、前記抵抗値の変化分をdR(k)とし前記インダクタンスの変化分をdL(k)とすると、
（ａ）＋dR(k)と＋dL(k)で巻線が加熱状態、
（ｂ）−dR(k)と＋dL(k)で巻線が放熱状態、
（ｃ）＋dR(k)と−dL(k)で巻線が部分短絡状態、
（ｄ）−dR(k)と−dL(k)で巻線短絡状態、
と判断することを特徴としている。
請求項２記載の発明は、誘導性負荷駆動制御装置に係り、巻き線を有する電磁石を駆動するリニアアンプを備えた誘導性負荷駆動制御装置において、前記巻き線の電圧と前記巻き線の電流とを使って前記巻き線の抵抗値を電圧方程式から逐次演算して求め、求めた抵抗値から前記巻き線の抵抗の温度係数を用いて巻き線の温度を算出してこの算出した温度を基に前記リニアアンプを制御する抵抗・インダクタンス演算部を備え、
前記抵抗・インダクタンス演算部は、下式から各時点の前記抵抗値とインダクタンス値をそれぞれ求め、

（ここで、Tはサンプリング周期、時刻ｔ＝kT時点（但しk=1,2,・・・,N）、Va(k)，Ia(k)，およびdP/dt(k)はkT時点の巻き線の各電圧、電流、および速度、Lは前記巻き線のインダクタンス、Keは誘起電圧定数で、誘起電圧eM(k)=Ke・dP/dt(k)である。）
それらの値の時間的変化に一定値以上の増（＋）減（−）があるとき、前記抵抗値の変化分をdR(k)とし前記インダクタンスの変化分をdL(k)とすると、
（ａ）＋dR(k)と＋dL(k)で巻線が加熱状態、
（ｂ）−dR(k)と＋dL(k)で巻線が放熱状態、
（ｃ）＋dR(k)と−dL(k)で巻線が部分短絡状態、
（ｄ）−dR(k)と−dL(k)で巻線短絡状態、
と判断することを特徴としている。
請求項３記載の発明は、誘導性負荷駆動制御装置に係り、交流を整流し平滑する整流平滑部と整流平滑した電圧を交流に変換する電力変換部を有し、３相巻き線を有するサーボモータを前記電力変換部の出力で駆動する誘導性負荷駆動制御装置であって、前記電力変換部を制御するベースドライブ部と、該ベースドライブ部を制御するＰＷＭ（パルス幅変調）演算部とを備えた誘導性負荷駆動制御装置において、
前記各相について前記巻き線の電圧と前記巻き線の電流と検出された前記サーボモータの出力軸の位置とを使って前記巻き線の抵抗値を電圧方程式から逐次演算して求め、求めた抵抗値から前記巻き線の抵抗の温度係数を用いて巻き線の温度を算出してこの算出した温度を基に前記ベースドライブ部を制御する抵抗・インダクタンス演算部を備え、
前記抵抗・インダクタンス演算部は、下式から各時点の前記抵抗値とインダクタンス値をそれぞれ求め、

（ここで、Tはサンプリング周期、時刻ｔ＝kT時点（但しk=1,2,・・・,N）、Va(k)，Ia(k)，およびdP/dt(k)はkT時点の巻き線の各電圧、電流、および速度、Lは前記巻き線のインダクタンス、Keは誘起電圧定数で、誘起電圧eM(k)=Ke・dP/dt(k)である。）
それらの値の時間的変化に一定値以上の増（＋）減（−）があるとき、前記抵抗値の変化分をdR(k)とし前記インダクタンスの変化分をdL(k)とすると、
（ａ）＋dR(k)と＋dL(k)で巻線が加熱状態、
（ｂ）−dR(k)と＋dL(k)で巻線が放熱状態、
（ｃ）＋dR(k)と−dL(k)で巻線が部分短絡状態、
（ｄ）−dR(k)と−dL(k)で巻線短絡状態、
と判断することを特徴としている。 In order to solve the above problem, the present invention is as follows.
An invention according to claim 1 relates to an inductive load drive control device, comprising: a rectifying / smoothing unit that rectifies and smoothes alternating current; a power converter that converts rectified and smoothed voltage into alternating current; and an electromagnetic actuator having a winding. An inductive load drive control device that is driven by the output of the power conversion unit, comprising: a base drive unit that controls the power conversion unit; and a PWM (pulse width modulation) calculation unit that controls the base drive unit In the inductive load drive control device, the winding resistance value is sequentially calculated from the voltage equation using the winding voltage, the winding current, and the detected position of the mover of the electromagnetic actuator. A resistance / inductance calculation unit for calculating the winding temperature from the obtained resistance value using the temperature coefficient of the resistance of the winding and controlling the base drive unit based on the calculated temperature Provided,
The resistance / inductance calculation unit obtains the resistance value and the inductance value at each time point from the following formula,

(Where T is the sampling period, time t = kT time (where k = 1, 2,..., N), Va (k), Ia (k), and dP / dt (k) are Each voltage, current, and speed of the winding, L is the inductance of the winding, Ke is an induced voltage constant, and the induced voltage eM (k) = Ke · dP / dt (k).
When there is an increase (+) or decrease (−) of a certain value or more in the temporal change of those values, if the change in the resistance value is dR (k) and the change in the inductance is dL (k),
(A) The winding is heated with + dR (k) and + dL (k)
(B) -dR (k) and + dL (k), winding is in heat dissipation state,
(C) The winding is partially short-circuited at + dR (k) and -dL (k).
(D) Winding short-circuited with -dR (k) and -dL (k)
It is characterized by judging .
The invention according to claim 2 relates to an inductive load drive control device, and in an inductive load drive control device comprising a linear amplifier for driving an electromagnet having a winding, the voltage of the winding and the current of the winding The resistance value of the winding is obtained by sequentially calculating from the voltage equation using, the temperature of the winding is calculated from the obtained resistance value using the temperature coefficient of the resistance of the winding, and the calculated temperature is used as a basis. A resistance / inductance calculation unit for controlling the linear amplifier is provided .
The resistance / inductance calculation unit obtains the resistance value and the inductance value at each time point from the following formula,

(Where T is the sampling period, time t = kT time (where k = 1, 2,..., N), Va (k), Ia (k), and dP / dt (k) are Each voltage, current, and speed of the winding, L is the inductance of the winding, Ke is an induced voltage constant, and the induced voltage eM (k) = Ke · dP / dt (k).
When there is an increase (+) or decrease (−) of a certain value or more in the temporal change of those values, if the change in the resistance value is dR (k) and the change in the inductance is dL (k),
(A) The winding is heated with + dR (k) and + dL (k)
(B) -dR (k) and + dL (k), winding is in heat dissipation state,
(C) The winding is partially short-circuited at + dR (k) and -dL (k).
(D) Winding short-circuited with -dR (k) and -dL (k)
It is characterized by judging .
A third aspect of the invention relates to an inductive load drive control device, and includes a rectifying / smoothing unit that rectifies and smoothes alternating current, a power conversion unit that converts the rectified and smoothed voltage into alternating current, and a servo having a three-phase winding. An inductive load drive control device for driving a motor with an output of the power conversion unit, comprising: a base drive unit that controls the power conversion unit; and a PWM (pulse width modulation) calculation unit that controls the base drive unit. In an inductive load drive control device provided,
For each phase, the resistance value of the winding is obtained by sequentially calculating the resistance value of the winding from the voltage equation using the winding voltage, the winding current and the detected position of the output shaft of the servo motor. A resistance / inductance calculation unit that calculates the temperature of the winding using the temperature coefficient of the resistance of the winding from the value and controls the base drive unit based on the calculated temperature ;
The resistance / inductance calculation unit obtains the resistance value and the inductance value at each time point from the following formula,

(Where T is the sampling period, time t = kT time (where k = 1, 2,..., N), Va (k), Ia (k), and dP / dt (k) are Each voltage, current, and speed of the winding, L is the inductance of the winding, Ke is an induced voltage constant, and the induced voltage eM (k) = Ke · dP / dt (k).
When there is an increase (+) or decrease (−) of a certain value or more in the temporal change of those values, if the change in the resistance value is dR (k) and the change in the inductance is dL (k),
(A) The winding is heated with + dR (k) and + dL (k)
(B) -dR (k) and + dL (k), winding is in heat dissipation state,
(C) The winding is partially short-circuited at + dR (k) and -dL (k).
(D) Winding short-circuited with -dR (k) and -dL (k)
It is characterized by judging .

According to a fourth aspect of the present invention, in the inductive load drive control device according to any one of the first to third aspects, when the resistance / inductance calculation unit determines that the winding is a partial short circuit or a short circuit state, The line abnormality is displayed on the display unit or an alarm is issued.
The invention according to claim 5 is the inductive load drive control device according to any one of claims 1 to 3, wherein the resistance of the copper wire at the temperature θ ₀ is R ₀ and the resistance at the temperature θx is R _X. Then, the temperature θx is obtained from the following equation.
θx = RX ・ (234.5 + θ0) / R0-234.5
According to a sixth aspect of the present invention, in the inductive load drive control device according to the fifth aspect , when the temperature θx of the winding exceeds a predetermined temperature, the resistance / inductance calculation unit determines that the state is overheated and displays It is characterized in that overheating is displayed on the part or an alarm is issued.

According to the first to sixth aspects of the present invention, the winding temperature of the electromagnetic actuator, which is a load, can be estimated, and overload protection is performed based on the estimated temperature. Therefore, the current supplied to the load under specific cooling conditions Unlike overload protection based on power and power, reliable overload protection can be realized, and L decreases or both L and R decrease due to the increase and decrease of winding inductance L and resistance R In such a case, the winding abnormality can be detected by making a judgment such as a short-circuiting of the winding, or a partial short-circuiting or the like when L is a normal value and R is very high.

  Hereinafter, specific examples of the method of the present invention will be described with reference to the drawings.

FIG. 1 is a functional block diagram when driving the electromagnetic actuator of the present invention, and FIG. 2 is an operation flowchart of the resistance / inductance calculation unit when driving the electromagnetic actuator of the present invention.
In FIG. 1, 10 is a drive control apparatus according to the present invention for driving an electromagnetic actuator, and 20 is an equivalent circuit of the electromagnetic actuator as a load. The equivalent circuit 20 of the electromagnetic actuator is represented by a resistance R (feed wire resistance Rr + electromagnetic actuator winding resistance Rw), inductance L, and induced voltage eM of the electromagnetic actuator.
The output voltage and output current of the drive control device 10 which is a PWM servo amplifier are detected by a voltage detection circuit D.V16 and a current detection circuit D.I17, and high-frequency carrier components are removed by low-pass filtering circuits Vfil16f and Ifil17f, respectively. The output voltage Va and the output current Ia are obtained.

On the other hand, a position detector D.P21 is mounted on the mover of the electromagnetic actuator 20, and the position P of the mover is detected by the position detector D.P21. The detected position P is the speed calculation unit S.P. Differentiated by C18 to obtain speed dP / dt.
When the output voltage Va, the output current Ia, and the speed dP / dt are input to the resistance / inductance calculation unit RLC15 and the sampling period is T, the time t = kT (where k = 1, 2,..., N). Assuming that the voltage Va, current Ia, and speed dP / dt are Va (k), Ia (k), dP / dt (k) (step S21 in FIG. 2), the following voltage equation (1) is obtained.
Va (k) = L [Ia (k) -Ia (k-1)] / T + R (k) · Ia (k) + Ke · dP / dt (k) (1)
Here, Ke is an induced voltage constant and eM (k) = Ke · dP / dt (k).
Similarly, at time t = (k + 1) T,
Va (k + 1) = L [Ia (k + 1) -Ia (k)] / T + R (k + 1) ・ Ia (k + 1) + Ke ・ dP / dt (k + 1) ・ ・・ (1) '
Equation (2) is obtained from Equation (1). (Step S22 in FIG. 2)
R (k) = [Va (k) -L [Ia (k) -Ia (k-1)] / T-Ke · dP / dt (k)] / Ia (k) (2)
Expression (2) is calculated by the resistance / inductance calculation unit 15 for each sampling period T. The resistance R (k) obtained by the equation (2) includes the resistance Rr of the feeder line, but with respect to the resistance Rw of the winding of the electromagnetic actuator,
When the resistance Rr of the power supply line can be ignored, Rw (k) = R (k) (3)
When the resistance Rr of the power supply line cannot be ignored, Rw (k) = R (k) -Rr (3) '
And
In the expression (3) ′, the temperature of the feeder line is small and almost constant, that is, Rr = constant (known).

By the way, when the resistance of the copper wire at the temperature θ ₀ is R ₀ , the resistance R _X at the temperature θx is a well-known equation.
R _X = R ₀・ (234.5 + θx) / (234.5 + θ ₀ ) (4)
From now on, θx = R _X・ (234.5 + θ ₀ ) / R ₀ -234.5 (5)
It becomes.
The resistance R ₀ of the copper wire at the temperature θ ₀ is known as Rw (k) in the equation (3) or (3) ′, and R _x is expressed as θx from the equation (5), that is, the winding temperature θw of the actuator. Is obtained (step S23 in FIG. 2).
When this θw exceeds the limit temperature θL according to the insulation class of the actuator or the temperature specification of the winding (step S24 in FIG. 2), output cutoff and OL (overload) are displayed as conventional overload protection operations. (Step S25 in FIG. 2).
Temperature θx and resistance R _X uses the limit resistance RL instead of limit temperature (allowable temperature) .theta.L because it is linear, may be determined overload protection operation (step S25 in FIG. 2).

これらのＬ（ｋ）とＲ（ｋ）が、一定時間に増減する割合ｄＬ（ｋ）とｄＲ（ｋ）の大きさを、移動平均によって求め（図２のステップＳ２７）、次の表１に従って巻き線の状態を判断し（図２のステップＳ２８）、抵抗・インダクタンス演算部１５で判断し、表示部１９に表示する（図２のステップＳ２９）。

表示部１９への表示に加えて、あるいはこれに代えて、表示内容を音声で報知するようにしてもよい。 Further, equation (6) is obtained by using inductances L = L (k) and R (k) = R (k + 1) as unknowns from equations (1) and (1) ′. This is also calculated by the resistance / inductance calculation unit 15 for each sampling period T (step S26 in FIG. 2).
Further, the resistance obtained as R (k) = R (k + 1) is regarded as not changing in a short time, but is updated to a new value after a certain time, that is, every T / = m · T. Here, m is a positive integer.

The magnitudes of the ratios dL (k) and dR (k) at which these L (k) and R (k) increase or decrease within a certain time are obtained by moving average (step S27 in FIG. 2), and according to the following Table 1 The state of the winding is determined (step S28 in FIG. 2), determined by the resistance / inductance calculation unit 15, and displayed on the display unit 19 (step S29 in FIG. 2).

In addition to or instead of the display on the display unit 19, the display content may be notified by voice.

FIG. 3 is a functional block diagram when driving the electromagnet of the present invention. FIG. 4 is an operation flowchart of the resistance / inductance calculation unit when driving the electromagnet of the present invention. In the figure, a drive control device 30 that controls the current of an electromagnet includes a linear amplifier 31. Therefore, unlike the PWM amplifier (rectifying / smoothing unit 11 + power converting unit 12) of FIG. 1, the output current ripple is not included, so that the voltage signal low-pass filter circuit 16f and the current signal low-pass filter circuit 17f in FIG. 1 are unnecessary. It is. Further, in the resistance / inductance calculation unit 35, for each sampling period T, from the output voltage Va and output current Ia (step S41 in FIG. 4) of the A / D converted load,
R (k) = [Va (k) -L [Ia (k) -Ia (k-1)] / T] / Ia (k) (7)
Is calculated (step S42 in FIG. 4).
Then, R (k)> R _L (limit resistance) is determined (step S43 in FIG. 4),
If true, overload is determined and output cutoff and OL (overload) are displayed (step S44 in FIG. 4). If false, the process proceeds to step S45.

Ｌ（ｋ）とＲ（ｋ）から、一定時間に増減する割合ｄＬ（ｋ）とｄＲ（ｋ）の大きさを、移動平均によって求め（図４のステップＳ４６）、表１に従って、巻き線の状態を判断し（図４のステップＳ４７）、抵抗・インダクタンス演算部３５で判断し、これを表示部３９に表示する（図４のステップＳ４８）。
また、表示部３９への表示に加えて、あるいはこれに代えて、表示内容を音声で報知するようにしてもよい。 In step S45, the expression (6) ′ is calculated.

From L (k) and R (k), the ratios dL (k) and dR (k) that increase or decrease in a certain time are obtained by moving average (step S46 in FIG. 4). The state is determined (step S47 in FIG. 4), and the resistance / inductance calculation unit 35 determines it and displays it on the display unit 39 (step S48 in FIG. 4).
Further, in addition to or instead of the display on the display unit 39, the display content may be notified by voice.

FIG. 5 is a functional block diagram for driving the servo motor of the present invention.
In the figure, 50 is a drive control device according to the present invention for driving a servo motor, and 60 is an equivalent circuit of a servo motor as a load. The equivalent circuit 60 of the servo motor is represented by the winding resistance Rw, inductance L, and induced voltage eM of the servo motor. The output voltage and output current of the drive control device 50 are detected by the voltage detection circuit 56 and the current detection circuit 57, respectively, and the high frequency carrier components are removed by the low-pass filtering circuits 56f and 57f, respectively, and the output voltage Va and the output current Ia are obtained. obtain.
On the other hand, a position detector 60a is mounted on the output shaft of the servomotor 60, and the position P of the output shaft is detected by the position detector 60a. dP / dt is obtained.
The phase / voltage Va, phase current Ia, and speed dP / dt for each phase (U phase, V phase, W phase) are input to the resistance / inductance calculation unit 55. Assuming that the sampling period is T, time t = kT (however, k = 1, 2,..., N) with phase voltage Va, phase current Ia, speed dP / dt as Va (k), Ia (k), dP / dt (k) Obtain the voltage equation (1).
In the case of the servo motor (equivalent circuit) 60, the induced voltage e _M must be taken into consideration, unlike the electromagnet of the second embodiment. Therefore, for each of the three phases U, V, and W, Equation (1) to Equation (3) or Equation (3) ′ is calculated by the resistance / inductance calculator 55, and the resistance R ( k) is compared with RL, and if R (k)> R _L (limit resistance), it is determined as an overload, and as a result, the output is cut off and OL (overload) is displayed.
When it is not overloaded, equation (6) is calculated for each phase, and the ratios dL (k) and dR (k) that increase or decrease in a certain time are obtained by moving average. The state of the line is determined and displayed on the display unit 59.
Further, in addition to or instead of the display on the display unit 59, the display content may be notified by voice.

  In this way, the output voltage and output current of the drive control device are detected and calculated according to the equations (1) to (5) to estimate the winding temperature of the load. Can be suppressed to a predetermined value, and reliable overload protection and winding abnormality can be detected.

  Even if the load is not an electromagnetic actuator having windings, if the equivalent circuit is represented by a series circuit of a resistor R and an inductance L, the induced voltage constant Ke is set to zero or the equivalent circuit is represented only by the resistor R. , Ke and L are set to zero, and a procedure of calculating with a microcomputer and comparing with a reference value according to formulas (1) to (5) is taken. Applicable.

Functional block diagram for driving the electromagnetic actuator of the present invention Operation flow chart of resistance / inductance calculation unit when driving electromagnetic actuator of the present invention Functional block diagram when driving the electromagnet of the present invention Operation flow chart of resistance / inductance calculation unit when driving electromagnet of the present invention Functional block diagram for driving the servo motor of the present invention It is a circuit diagram which shows the conventional overload protection.

Explanation of symbols

10, 30, 50 Drive control device 15, 35, 55 according to the present invention Resistance / inductance calculation unit RLC
16, 36, 56 Voltage detection circuit DV
16f, 56f Voltage signal low-pass filter circuit Vfil
17, 37, 57 Current detection circuit DI
17f, 57f Current signal low-pass filter circuit Ifil
18, 38, 58 Speed calculator SC
20 Equivalent circuit 21 of electromagnetic actuator, 60a Position detector DP
40 Equivalent circuit of electromagnet 60 Equivalent circuit of servo motor
eM induced voltage
Ia Output current L Inductance R Electromagnetic actuator resistance
Rr Feed line resistance
Rw Winding resistance
R _L (Temperature) Limit resistance T Sample period Va Output voltage

Claims (6)

An inductive load drive control device that includes a rectifying / smoothing unit that rectifies and smoothes alternating current and a power conversion unit that converts the rectified and smoothed voltage into alternating current, and drives an electromagnetic actuator having a winding by the output of the power converting unit. In the inductive load drive control device comprising a base drive unit that controls the power conversion unit and a PWM (pulse width modulation) calculation unit that controls the base drive unit, the voltage of the winding and the winding The resistance value of the winding is obtained by sequentially calculating from the voltage equation using the detected current and the detected position of the mover of the electromagnetic actuator, and the temperature coefficient of the resistance of the winding is obtained from the obtained resistance value. A resistance / inductance calculation unit that calculates the temperature of the winding and controls the base drive unit based on the calculated temperature ,
The resistance / inductance calculation unit obtains the resistance value and the inductance value at each time point from the following formula,

(Where T is the sampling period, time t = kT time (where k = 1, 2,..., N), Va (k), Ia (k), and dP / dt (k) are Each voltage, current, and speed of the winding, L is the inductance of the winding, Ke is an induced voltage constant, and the induced voltage eM (k) = Ke · dP / dt (k).
When there is an increase (+) or decrease (−) of a certain value or more in the temporal change of those values, if the change in the resistance value is dR (k) and the change in the inductance is dL (k),
(A) The winding is heated with + dR (k) and + dL (k)
(B) -dR (k) and + dL (k), winding is in heat dissipation state,
(C) The winding is partially short-circuited at + dR (k) and -dL (k).
(D) Winding short-circuited with -dR (k) and -dL (k)
Inductive load drive control apparatus characterized by determining the. In an inductive load drive control device including a linear amplifier for driving an electromagnet having a winding, a resistance value of the winding is sequentially calculated from a voltage equation using a voltage of the winding and a current of the winding. A resistance / inductance calculation unit for controlling the linear amplifier based on the calculated temperature by calculating the temperature of the winding using the temperature coefficient of the resistance of the winding from the obtained resistance value ,
The resistance / inductance calculation unit obtains the resistance value and the inductance value at each time point from the following formula,

(Where T is the sampling period, time t = kT time (where k = 1, 2,..., N), Va (k), Ia (k), and dP / dt (k) are Each voltage, current, and speed of the winding, L is the inductance of the winding, Ke is an induced voltage constant, and the induced voltage eM (k) = Ke · dP / dt (k).
When there is an increase (+) or decrease (−) of a certain value or more in the temporal change of those values, if the change in the resistance value is dR (k) and the change in the inductance is dL (k),
(A) The winding is heated with + dR (k) and + dL (k)
(B) -dR (k) and + dL (k), winding is in heat dissipation state,
(C) The winding is partially short-circuited at + dR (k) and -dL (k).
(D) Winding short-circuited with -dR (k) and -dL (k)
Inductive load drive control apparatus characterized by determining the. An inductive load drive control device having a rectifying / smoothing unit for rectifying and smoothing alternating current, and a power conversion unit for converting the rectified and smoothed voltage into alternating current, and driving a servo motor having a three-phase winding by the output of the power converting unit In an inductive load drive control device including a base drive unit that controls the power conversion unit and a PWM (pulse width modulation) calculation unit that controls the base drive unit,
For each phase, the resistance value of the winding is obtained by sequentially calculating the resistance value of the winding from the voltage equation using the winding voltage, the winding current and the detected position of the output shaft of the servo motor. A resistance / inductance calculation unit that calculates the temperature of the winding using the temperature coefficient of the resistance of the winding from the value and controls the base drive unit based on the calculated temperature ;
The resistance / inductance calculation unit obtains the resistance value and the inductance value at each time point from the following formula,

(Where T is the sampling period, time t = kT time (where k = 1, 2,..., N), Va (k), Ia (k), and dP / dt (k) are Each voltage, current, and speed of the winding, L is the inductance of the winding, Ke is an induced voltage constant, and the induced voltage eM (k) = Ke · dP / dt (k).
When there is an increase (+) or decrease (−) of a certain value or more in the temporal change of those values, if the change in the resistance value is dR (k) and the change in the inductance is dL (k),
(A) The winding is heated with + dR (k) and + dL (k)
(B) -dR (k) and + dL (k), winding is in heat dissipation state,
(C) The winding is partially short-circuited at + dR (k) and -dL (k).
(D) Winding short-circuited with -dR (k) and -dL (k)
Inductive load drive control apparatus characterized by determining the.   The resistance / inductance calculation unit displays a winding abnormality on a display unit or issues an alarm warning when the winding is determined to be partially short-circuited or short-circuited. The inductive load drive control device according to claim 1. 4. The induction according to claim 1, wherein the resistance of the copper wire at the temperature θ ₀ is R ₀ and the resistance at the temperature θx is R _X , the temperature θx is obtained from the following equation. Load drive control device.
θx = RX ・ (234.5 + θ0) / R0-234.5   6. The resistance / inductance calculation unit, when a temperature θx of the winding exceeds a predetermined temperature, determines that the coil is overheated and displays an overheat on the display unit or issues an alarm warning. The inductive load drive control device described.

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