JP3612953B2 - Induction motor control device - Google Patents

Description

【００２２】
【数６】
τ_１２＝（ＧＤ^２ ／３７５）・Δｎ〔ｋｇｆｍ〕 …（６） ここで、 ｍ：荷重質量〔ｋｇ〕
ＣＭ：カウンタウェイト質量〔ｋｇ〕
ｖ：昇降速度〔ｍ／ｍｉｎ〕
ｎ：電動機回転速度〔ｒ／ｍｉｎ〕
Δｎ：電動機回転加速度〔ｒ／ｍｉｎ／ｓ〕
ＧＤ^２ ：電動機軸換算全はずみ車効果〔ｋｇｆｍ^２ 〕
図１に示したこの発明の誘導電動機の制御装置の動作を以下に説明をする。
【００２３】
先ず、荷重ｍとカウンタウェイトＣＷとが同じ質量になるバランス状態に設定し、誘導電動機９を定格速度での定速運転を行わせることにより、このときの速度調節器３の出力のトルク指令値τ^＊ を読み取り、この値をトルク設定回路２３にプリセットする。すなわち、上記状態での定速運転では式（４）〜式（６）の値が零となるので、式（１），式（２）から機械損補償トルクτ_０２が求まる。
【００２４】
なお、このシステムにおける機械損補償トルクτ_０２は、減速機１０ａの効率に基づくものが大勢を占めるので、上述のバランス状態を設定することが困難な場合には、式（７）で得られる値をトルク設定回路２３にプリセットしてもよい。
【００２５】
【数７】

また、上述のいずれかで得られた機械損補償トルクτ_０２は、図３に示す如く誘導電動機９の回転方向によりその極性が異なるので、トルク設定回路２３には速度検出器６の検出値（ｎ）を取り込み、極性を持った機械損補償トルクτ_０２を出力するようにしている。
【００２６】
次に、前記式（６）の電動機と巻上機に対する加減速必要トルクτ_１２は、予め設定できる電動機軸換算全はずみ車効果（ＧＤ^２ ）と、後述の加速度演算回路２１で得られる加速度（Δｎ）とに基づく乗算演算を加速トルク演算回路２２にて行えばよい。
加速度演算回路２１では、式（８）の演算を行っている。
【００２７】
【数８】
Δｎ＝（ｎ_ｋ −ｎ_{（ｋ−１）} ）／Ｔ_Ｓ 〔ｒ／ｍｉｎ／ｓ〕 …（８）
ここで、 ｎ_ｋ ：今回の電動機速度検出値〔ｒ／ｍｉｎ〕
ｎ_{（ｋ−１）} ：前回の電動機速度検出値〔ｒ／ｍｉｎ〕
Ｔ_Ｓ ：検出周期〔ｓ〕
なお、加速度（Δｎ）として単一積分器２に設定されている値を用いて行うこともできる。
【００２８】
トルク設定回路２３の出力の機械損補償トルクτ_０２と加速トルク演算回路２２の出力の加減速必要トルクτ_１２とを、前記式（１）〜式（３）に代入することにより、式（９）が得られる。
【００２９】
【数９】
τ_０１＋τ_１１＝τ^＊ −τ_０２−τ_１２ …（９）
すなわち、前記式（４）と式（５）と式（９）とには、式（４）＋式（５）＝式（９）の関係があるので、この関係式に基づいて荷重推定回路２４では荷重ｍを求める演算を行っている。
【００３０】
またトルク演算回路２５において、荷重推定回路２４で得られた荷重ｍの推定値と前記式（４）とから荷重ｍとカウンタウェイトＣＷに対する走行トルクτ_０１が求まり、同様に前記式（５）とから荷重ｍとカウンタウェイトＣＷに対する加減速必要トルクτ_１１が求まる。
次に、速度演算回路２６での誘導電動機９の運転可能最大速度指令値（Ｎ_０ ^＃ ）を求める演算について説明をする。
【００３１】
先ず、加速トルク演算回路２２の演算値（τ_１２）とトルク設定回路２３の設定値（τ_０２）とトルク演算回路２５の演算値（τ_０１，τ_１１）と、巻上機１０ｂを加減速に必要な誘導電動機９の出力トルクの最大値（τ_Ｍ１）とには式（１０）の関係がある（図８参照）。
【００３２】
【数１０】
τ_Ｍ１＝｜τ_０１＋τ_０２｜＋｜τ_１１＋τ_１２｜ …（１０）
次に、図４に示す誘導電動機９の短時間運転許容トルク−回転速度特性図（第１象限のみを図示）における前記τ_Ｍ１に対応する誘導電動機９の速度値（Ｎ_０１ ^＃ ）を求める。
【００３３】
なおこの速度値（Ｎ_０１ ^＃ ）は、式（１１）の関係にある。
【００３４】
【数１１】
Ｎ_０１ ^＃ ＝（τ_Ａ ／τ_Ｍ１）・Ｎ_Ｂ …（１１）
ここで、Ｎ_Ｂ ：電動機定格速度
τ_Ａ ：電動機定格速度の短時間運転許容トルク
また、階床の多いエレベータ式立体駐車場などにこのシステムを適用する場合には、定速で昇降させる時間も長くなることから巻上機１０ｂを定速運転に必要な誘導電動機９の出力トルクの最大値（τ_Ｍ２）は、式（１２）の関係にある（図８参照）。
【００３５】
【数１２】
τ_Ｍ２＝｜τ_０１＋τ_０２｜ …（１２）
このときには、図５に示す誘導電動機９の連続運転許容トルク−回転速度特性図（第１象限のみを図示）における前記τ_Ｍ２に対応する誘導電動機９の速度値（Ｎ_０２ ^＃ ）を求める。
【００３６】
なおこの速度値（Ｎ_０２ ^＃ ）は、式（１３）の関係にある。
【００３７】
【数１３】
Ｎ_０２ ^＃ ＝（τ_Ａ ／τ_Ｍ２）・Ｎ_Ｂ …（１３）
ここで、Ｎ_Ｂ ：電動機定格速度
τ_Ｂ ：電動機定格速度の連続運転許容トルク
すなわち、速度演算回路２６では前記Ｎ_０１ ^＃ またはＮ_０２ ^＃ のいずれか小さい方の値を誘導電動機９の運転可能最大速度指令値（Ｎ_０ ^＃ ）として出力する。または、このシステムの動作モードに合わせて、当該する前記Ｎ_０１ ^＃ またはＮ_０２ ^＃ のいずれか一方の値を選択して、誘導電動機９の運転可能最大速度指令値（Ｎ_０ ^＃ ）として出力する。
【００３８】
さらに、速度指令値変換回路２７では速度指令器１の指令値（Ｎ^＃ ）または速度演算回路２６の演算値（Ｎ_０ ^＃ ）のいずれか大きい方の値を新たな速度指令値（Ｎ^＃ ）として、単一積分器２に出力する。
【００３９】
【発明の効果】
この発明によれば、上述の荷重推定回路で推定した荷重、誘導電動機の短時間及び連続の許容トルク−速度特性などから該誘導電動機の運転可能最大速度を算定し、この速度で運転することにより、例えばエレベータ式立体駐車場などにこの誘導電動機の制御装置を適用したときに、該立体駐車場の利用効率の改善がなされる。
【図面の簡単な説明】
【図１】この発明の実施例を示す誘導電動機の制御装置のブロック図
【図２】図１の動作を説明する誘導電動機の負荷の構成図
【図３】図１，２の動作を説明する誘導電動機の負荷の特性図
【図４】図１，２の動作を説明する誘導電動機の特性図
【図５】図１，２の動作を説明する誘導電動機の特性図
【図６】従来例を示す誘導電動機の制御装置のブロック図
【図７】図６の動作を説明するタイムチャート
【図８】図２，６の動作を説明する誘導電動機の負荷の特性図
【符号の説明】
１…速度指令器、２…単一積分器、３…速度調節器、４…磁束指令値演算器、５…ベクトル演算器、６…速度検出器、７…交流電源、８…インバータ、９…誘導電動機、１０…負荷、２１…加速度演算回路、２２…加速トルク演算回路、２３…トルク設定回路、２４…荷重推定回路、２５…トルク演算回路、２６…速度演算回路、２７…速度指令値変換回路。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an induction motor control apparatus that performs variable speed control of an induction motor as a drive source of a hoisting machine by vector control.
[0002]
[Prior art]
FIG. 6 is a block diagram showing a conventional example of an induction motor control device that performs variable speed control of this type of induction motor by vector control. 1 is a speed commander, 2 is a single integrator, and 3 is a speed regulator. Reference numeral 4 is a magnetic flux command value calculator, 5 is a vector calculator, 6 is a speed detector, 7 is an AC power source, 8 is an inverter, 9 is an induction motor, and 10 is a load.
[0003]
In FIG. 6, the speed command device 1 commands a speed command value (N ^# ) of the rotational speed at which the induction motor 9 should operate. The single integrator 2 increases or decreases until reaching the speed command value (N ^# ) at a predetermined acceleration gradient (increase value / unit time) or deceleration gradient (decrease value / unit time) (N ^* = N ^# ). The speed setting value (N ^* ) to be output is output. The speed adjuster 3 adjusts the deviation between the speed set value (N ^* ) and the detected value (n) of the speed detector 6 and outputs a torque command value (τ ^* ) that makes the deviation zero. . The magnetic flux command value calculator 4 calculates and outputs a magnetic flux command value (φ ^* ) from the detected value (n).
[0004]
The vector calculator 5 outputs a control signal for vector control of the inverter 8 from the torque command value (τ ^* ) and the magnetic flux command value (φ ^* ). As a result, the power of the AC power source 7 is desired by the inverter 8. The induction motor 9 that is converted into AC power having a voltage and a frequency of and supplied with AC power output from the inverter 8 can be controlled at a variable speed by vector control.
[0005]
FIG. 7 is a time chart showing the relationship between the speed command value (N ^# ) and the speed set value (N ^* ).
7, the forward direction of the velocity command value at time T ₀ when the (N ^#) is issued, the period from time T ₀ to time T _1, the acceleration gradient (increasing value set to a single integrator 2 / unit time) speed setting value based on the ^{(N *)} is increased in the forward direction, the time ^{that N} * = ^{N #} next at time _{T 1,} the speed command value from the time _{T 1} ^{(N #)} is zero time to T ₂ are a single integrator 2 outputs a ^N * (= ^{N #),} the period from time _{T 2,} to time _{T 3,} the deceleration gradient (decreasing values set in the single integrator 2 / based on the unit time) to reduce the forward direction of the value of the speed setpoint ^{(N *), N * =} 0 , and the speed command value from the time _{T 3} at time _{T 3} ^{(N #)} speed in the reverse direction command value ^{(N #)} is the period until the time _{T 4} emitted a single integrator 2 outputs a ^N * (= 0), from time _{T 4} Time to time _{T 5,} the speed setting value based on the deceleration gradient ^{(N *)} increases the value of the reverse direction of time _{T 5} by ^N * = ^{N #,} and the speed command value from the time _{T 5} (N ^In the period from time T ₆ until time T ₆ to zero, the single integrator 2 outputs N ^* (= N ^# ), and the period from time T ₆ to time T ₇ is based on the acceleration gradient. speed setpoint ^{(N *)} was the value in the reverse direction reducing the, the ^N * = 0 at time _{T 7.}
[0006]
Each control element included in the above-described induction motor control device can be configured using a well-known technique, and thus a detailed description thereof is omitted.
FIG. 8 is a diagram illustrating the operation of a system for driving a hoisting machine having a counterweight (CW in the drawing) as a load 10 of the induction motor 9 through a speed reducer by the conventional induction motor control device shown in FIG. FIG. 8 (a) shows the state of the hoisting machine equipped with the counterweight (CW), FIG. 8 (b) shows the speed of the induction motor 9 that raises and lowers the hoisting machine, and FIG. D) shows the output torque of the induction motor 9 as the hoisting machine moves up and down.
[0007]
That is, in the period before time t ₀ , the load (m in the figure) is on the ground. At this time, the induction motor 9 is stopped (speed = 0) and is braked by a brake (not shown).
First, although starts from the hoisting machine hoisting time t _0, left end view of FIG. 8 (b) shows the state of the hoisting machine of the time t _0, the brake is opened at time t _0, From time t ₀ to time t ₁ , a period during which the hoisting speed (v) of the hoisting machine is increased at the acceleration gradient set in the single integrator 2 is shown. At time _{t 1,} the speed command value ^{(N #)} the speed setpoint ^{(N *)} and match, is from time _{t 1} to time _{t 2} speed winding hoisting machine (v) represents the period of time ing. From time t ₂ to time t ₃ represents the time which reduces the hoisting speed of the hoisting machine (v) the deceleration gradient which is set to said single integrator 2. From time t ₃ to time t ₄ , the induction motor 9 is stopped (speed = 0) and is braked by the brake. During this period, as shown in the center of the drawing in FIG. The illustrated m) is stopped in the air.
[0008]
Then, rather than time t ₄ to time t ₅ shows a period in which increases the lowering speed (v) of the hoisting machine in the deceleration gradient which is set to said single integrator 2. At time _{t 5,} the speed command value ^{(N #)} the speed setpoint ^{(N *)} and match, is from time _{t 5} to time _{t 6} speed lower winding hoisting machine (v) is a period of time Show. Until time t ₇ to the time t ₆ shows a period in which to reduce the lowering speed (v) of the hoisting machine with an acceleration gradient set in the single integrator 2. Time t ₇ loads the period after (shown m) is located on the ground, the induction motor 9 at this time is multiplied is braked by has stopped (speed = 0), and the brake. Right end view of FIG. 8 (b) shows the state of the hoisting machine of the time t _7.
[0009]
As shown in FIG. 8, the output torque of the induction motor 9 (τ ₀ shown) necessary for the constant travel of the hoisting machine and the output torque of the induction motor 9 required for acceleration or deceleration of the hoisting machine (τ shown) ₀ ± τ ₁ ) is different in polarity and value depending on the relationship between the load (m in the figure) and the counterweight (CW in the figure). FIG. 8 (c) shows m> CW, FIG. The output torque pattern of the induction motor 9 when m <CW is shown.
[0010]
[Problems to be solved by the invention]
In a system in which an induction motor fed by the above-described conventional inverter drives a hoist equipped with a counterweight via a speed reducer, the maximum traveling speed at the maximum load of the hoist and acceleration / deceleration at the maximum load The rated speed and rated output torque of the induction motor were selected based on the maximum required torque value and the gear ratio of the reduction gear.
[0011]
However, for example, when this system is applied to an elevator type multi-story parking lot, etc., the weight of each vehicle as a load is different, and the vehicle may be moved up and down by an empty vehicle when entering or leaving the vehicle. It is rare to raise and lower at the maximum load, and in most cases, it is often raised and lowered at a light load that does not reach the maximum load, and the induction motor adopted under the above selection conditions will reduce the use efficiency of the system There were difficulties.
[0012]
An object of the present invention is to provide an induction motor control device that solves the above-described problems and raises and lowers at a higher speed when raising and lowering with a light load, thereby improving the utilization efficiency of the system. It is in.
[0013]
[Means for Solving the Problems]
The present invention is a system in which an induction motor fed by an inverter drives a hoist equipped with a counterweight via a speed reducer, and based on a speed command value (N ^# ) commanded to the induction motor, The speed setting value (N ^* ) reaches the speed command value (N ^# ) at a predetermined acceleration gradient (increase value / unit time) or a predetermined deceleration gradient (decrease value / unit time) (N ^* = N ^# ) Torque command value (τ ^* ) obtained by adjusting and calculating the deviation between the speed setting value (N ^* ) to be increased or decreased to the speed detection value (n) of the induction motor, and the speed detection value (n) In a control apparatus for an induction motor that performs a vector calculation with a magnetic flux command value (φ ^* ) obtained by calculating from the above, and performs variable speed control of the induction motor via the inverter based on the vector calculation value,
An acceleration calculation circuit for calculating the acceleration (Δn) of the induction motor from the speed detection value (n), a calculation value (Δn) of the acceleration calculation circuit, and a preset all flywheel effect (GD ² ) in terms of the induction motor shaft. Acceleration / deceleration required torque (τ ₁₂ ) for the induction motor and hoisting machine based on the above, and torque for presetting the mechanical loss compensation torque (τ ₀₂ ) corresponding to the maximum mechanical loss of the system The setting circuit, the torque command value (τ ^* ), the calculation value (Δn) of the acceleration calculation circuit, the calculation value (τ ₁₂ ) of the acceleration torque calculation circuit, and the setting value (τ ₀₂ ) of the torque setting circuit are set in advance. Load (m) lifted by the hoisting machine from the mass of counterweight (CW), the rotational speed (n) of the induction motor, and the hoisting / lowering speed (v) of the hoisting machine at the rotational speed (n) Estimated load From the estimation circuit, the estimated value (m) of the load estimation circuit, the mass (CW) of the counterweight, the rotational speed (n), the lifting speed (v), and the calculated value (Δn) of the acceleration calculating circuit A torque calculation circuit that calculates a running torque (τ ₀₁ ) and acceleration / deceleration required torque (τ ₁₁ ) for the weight and the load (m), an operation value (τ ₁₂ ) of the acceleration torque calculation circuit, and a setting value of the torque setting circuit (Τ ₀₂ ), the calculated value of the torque calculation circuit (τ ₀₁ , τ ₁₁ ), and the short-time and continuous allowable torque-speed characteristics of the induction motor, the maximum operable speed command value (N ₀ ^# ) of the induction motor. And a speed command value conversion circuit that uses the maximum operable speed command value (N ₀ ^# ) as a new speed command value (N ^# ).
[0014]
According to the present invention, the maximum operating speed of the induction motor is calculated from the load estimated by the load estimation circuit, the short time and continuous allowable torque-speed characteristics of the induction motor, and the system is operated by operating at this speed. The utilization efficiency is improved.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a block diagram of a control device for an induction motor (hereinafter also simply referred to as an electric motor) showing an embodiment of the present invention. Components having the same functions as those in the conventional block diagram shown in FIG. A description thereof will be omitted.
That is, in FIG. 1, in addition to the conventional control elements, this control device includes an acceleration calculation circuit 21, an acceleration torque calculation circuit 22, a torque setting circuit 23, a load estimation circuit 24, a torque calculation circuit 25, a speed An arithmetic circuit 26 and a speed command value conversion circuit 27 are added.
[0016]
FIG. 2 shows a configuration showing a system comprising a hoisting machine 10b through a speed reducer 10a as a load 10 of the induction motor 9, a counter weight (CW shown) and a load (m shown) of the hoisting machine 10b. FIG.
In FIG. 2, when the induction motor 9 rotates at the rotational speed n [r / min], the hoisting machine 10 b rotates through the speed reducer 10 a, and the load m increases and decreases at the speed v [m / min]. To do. The torque command value (τ ^* ), the running torque (τ ₀ ), and the acceleration / deceleration required torque (output) of the speed regulator 3 during acceleration or deceleration, that is, the period during which the speed set value (N ^* ) is increasing or decreasing. (τ ₁ ) has the relationship of equation (1).
[0017]
[Expression 1]
τ ^* = τ ₀ + τ ₁ (1)
This running torque (τ ₀ ) is decomposed into two components shown on the right side of Equation (2).
[0018]
[Expression 2]
τ ₀ = τ ₀₁ + τ ₀₂ (2)
Here, τ ₀₁ : Traveling torque for load m and counterweight CW τ ₀₂ : Mechanical loss compensation torque Further, acceleration / deceleration required torque (τ ₁ ) is decomposed into two components shown on the right side of Expression (3).
[0019]
[Equation 3]
τ ₁ = τ ₁₁ + τ ₁₂ (3)
Here, τ ₁₁ : Necessary acceleration / deceleration torque τ ₁₂ for load m and counterweight CW: Necessary acceleration / deceleration torque for motor and hoisting machine τ ₀₁ , τ ₁₁ , and τ ₁₂ are expressed by the formula (4 ) To formula (6).
[0020]
[Expression 4]
τ ₀₁ = (m−CW) · (v / 2πn) [kgfm] (4)
[0021]
[Equation 5]

[0022]
[Formula 6]
^{_{τ 12 = (GD 2/375}} ) · Δn [kgfm] ... (6) where, m: Load Weight (kg)
CM: Counterweight mass [kg]
v: Lifting speed [m / min]
n: Motor rotation speed [r / min]
Δn: Motor rotation acceleration [r / min / s]
GD ² : Motor shaft equivalent all flywheel effect [kgfm ² ]
The operation of the induction motor control apparatus of the present invention shown in FIG. 1 will be described below.
[0023]
First, by setting the balance state in which the load m and the counterweight CW have the same mass, and causing the induction motor 9 to perform constant speed operation at the rated speed, the torque command value of the output of the speed regulator 3 at this time τ ^* is read and this value is preset in the torque setting circuit 23. That is, in the constant speed operation in the above state, since the values of the equations (4) to (6) are zero, the mechanical loss compensation torque τ ₀₂ is obtained from the equations (1) and (2).
[0024]
The mechanical loss compensation torque τ ₀₂ in this system is mostly based on the efficiency of the speed reducer 10a. Therefore, when it is difficult to set the above-described balance state, the value obtained by Expression (7) May be preset in the torque setting circuit 23.
[0025]
[Expression 7]

Further, since the mechanical loss compensation torque τ ₀₂ obtained by any of the above varies in polarity depending on the rotation direction of the induction motor 9 as shown in FIG. 3, the torque setting circuit 23 has a detection value ( n) is taken in and a mechanical loss compensation torque τ ₀₂ having polarity is output.
[0026]
Next, the acceleration / deceleration required torque τ ₁₂ for the electric motor and hoisting machine of the above formula (6) is a motor shaft equivalent total flywheel effect (GD ² ) that can be set in advance and an acceleration (Δn) obtained by an acceleration calculation circuit 21 described later. ) And the acceleration torque calculation circuit 22 may perform the multiplication calculation.
In the acceleration calculation circuit 21, the calculation of Expression (8) is performed.
[0027]
[Equation 8]
Δn = (n _k −n _(k−1) ) / T _S [r / min / s] (8)
Where n _k : current motor speed detection value [r / min]
n _(k−1) : previous motor speed detection value [r / min]
T _S : Detection period [s]
In addition, it can also carry out using the value set to the single integrator 2 as acceleration ((DELTA) n).
[0028]
By substituting the mechanical loss compensation torque τ ₀₂ of the output of the torque setting circuit 23 and the acceleration / deceleration required torque τ ₁₂ of the output of the acceleration torque calculation circuit 22 into the expressions (1) to (3), the expression (9 ) Is obtained.
[0029]
[Equation 9]
τ ₀₁ + τ ₁₁ = τ ^* −τ ₀₂ −τ ₁₂ (9)
That is, since the formula (4), the formula (5), and the formula (9) have the relationship of the formula (4) + the formula (5) = the formula (9), the load estimation circuit is based on this relational expression. 24 calculates the load m.
[0030]
The torque calculation circuit 25 obtains the running torque τ ₀₁ for the load m and the counterweight CW from the estimated value of the load m obtained by the load estimation circuit 24 and the above equation (4). Similarly, the equation (5) Thus, the acceleration / deceleration required torque τ ₁₁ for the load m and the counterweight CW is obtained.
Next, calculation for obtaining the maximum operable speed command value (N ₀ ^# ) of the induction motor 9 in the speed calculation circuit 26 will be described.
[0031]
First, the calculated value (τ ₁₂ ) of the acceleration torque calculating circuit 22, the set value (τ ₀₂ ) of the torque setting circuit 23, the calculated values (τ ₀₁ , τ ₁₁ ) of the torque calculating circuit 25, and the hoisting machine 10 b are accelerated / decelerated. (10) is related to the maximum value (τ _M1 ) of the output torque of the induction motor 9 required for the above (see FIG. 8).
[0032]
[Expression 10]
τ _M1 = | τ ₀₁ + τ ₀₂ | + | τ ₁₁ + τ ₁₂ | (10)
Next, the speed value (N ₀₁ ^# ) of the induction motor 9 corresponding to the τ _M1 in the short-time operation allowable torque-rotational speed characteristic diagram (only the first quadrant is shown) of the induction motor 9 shown in FIG. 4 is obtained.
[0033]
Note that this speed value (N ₀₁ ^# ) has a relationship of Expression (11).
[0034]
[Expression 11]
N ₀₁ ^# = (τ _A / τ _M1 ) · N _B (11)
Here, N _B : Motor rated speed τ _A : Motor rated speed short-time operation allowable torque In addition, when this system is applied to an elevator type multilevel parking lot with many floors, the time required to move up and down at a constant speed is Since it becomes long, the maximum value (τ _M2 ) of the output torque of the induction motor 9 necessary for the constant speed operation of the hoisting machine 10b is in the relationship of the equation (12) (see FIG. 8).
[0035]
[Expression 12]
τ _M2 = | τ ₀₁ + τ ₀₂ | (12)
At this time, the speed value (N ₀₂ ^# ) of the induction motor 9 corresponding to τ _M2 in the continuous operation allowable torque-rotational speed characteristic diagram (only the first quadrant is shown) of the induction motor 9 shown in FIG. 5 is obtained.
[0036]
This speed value (N ₀₂ ^# ) is in the relationship of equation (13).
[0037]
[Formula 13]
N ₀₂ ^# = (τ _A / τ _M2 ) · N _B (13)
Here, N _B : motor rated speed τ _B : continuous operation allowable torque of motor rated speed, that is, in the speed calculation circuit 26, the smaller one of N ₀₁ ^{# and} N ₀₂ ^# is set to the maximum operable value of the induction motor 9. Output as speed command value (N ₀ ^# ). Alternatively, according to the operation mode of this system, either one of the relevant N ₀₁ ^# or N ₀₂ ^# is selected and output as the maximum operable speed command value (N ₀ ^# ) of the induction motor 9. .
[0038]
Furthermore, the speed command value conversion circuit 27 in the speed command unit 1 of the command value (N ^#) or calculation of the velocity calculation circuit 26 (N 0 ^_#) whichever is larger the new speed command value for the (N ^#) Is output to the single integrator 2.
[0039]
【The invention's effect】
According to the present invention, the maximum operable speed of the induction motor is calculated from the load estimated by the load estimation circuit, the short time and continuous allowable torque-speed characteristics of the induction motor, and the operation is performed at this speed. When the induction motor control device is applied to, for example, an elevator type multi-story parking lot, the use efficiency of the multi-story parking lot is improved.
[Brief description of the drawings]
FIG. 1 is a block diagram of an induction motor control apparatus showing an embodiment of the present invention. FIG. 2 is a configuration diagram of a load of an induction motor for explaining the operation of FIG. 1. FIG. FIG. 4 is a characteristic diagram of the induction motor load. FIG. 4 is a characteristic diagram of the induction motor explaining the operation of FIGS. 1 and 2. FIG. 5 is a characteristic diagram of the induction motor explaining the operation of FIGS. FIG. 7 is a time chart illustrating the operation of FIG. 6. FIG. 8 is a characteristic diagram of the load of the induction motor illustrating the operation of FIGS.
DESCRIPTION OF SYMBOLS 1 ... Speed command device, 2 ... Single integrator, 3 ... Speed regulator, 4 ... Magnetic flux command value calculator, 5 ... Vector calculator, 6 ... Speed detector, 7 ... AC power supply, 8 ... Inverter, 9 ... Induction motor, 10 ... load, 21 ... acceleration calculation circuit, 22 ... acceleration torque calculation circuit, 23 ... torque setting circuit, 24 ... load estimation circuit, 25 ... torque calculation circuit, 26 ... speed calculation circuit, 27 ... speed command value conversion circuit.

Claims (1)

An induction motor fed by an inverter is a system for driving a hoisting machine equipped with a counterweight via a speed reducer,
Based on the speed command value (N ^# ) commanded to the induction motor, the current speed set value (N ^* ) is set to a predetermined acceleration gradient (increase value / unit time) or a predetermined deceleration gradient (decrease value / unit time). To adjust the deviation between the speed setting value (N ^* ) that is increased or decreased until reaching the speed command value (N ^# ) (N ^* = N ^# ) and the speed detection value (n) of the induction motor. Vector calculation is performed based on the obtained torque command value (τ ^* ) and the magnetic flux command value (φ ^* ) obtained by calculation from the speed detection value (n). In the induction motor control device for variable speed control of the induction motor,
An acceleration calculation circuit for calculating the acceleration (Δn) of the induction motor from the speed detection value (n);
Acceleration torque for calculating the acceleration / deceleration required torque (τ ₁₂ ) for the induction motor and the hoisting machine based on the calculated value (Δn) of the acceleration calculation circuit and the preset total flywheel effect (GD ² ) in terms of the induction motor shaft. An arithmetic circuit;
A torque setting circuit for presetting a mechanical loss compensation torque (τ ₀₂ ) corresponding to the maximum mechanical loss value of the system;
The torque command value (τ ^* ), the calculation value (Δn) of the acceleration calculation circuit, the calculation value (τ ₁₂ ) of the acceleration torque calculation circuit, the set value (τ ₀₂ ) of the torque setting circuit, and the preset weight of the counterweight The load that estimates the load (m) that the hoisting machine moves up and down from (CW), the rotational speed (n) of the induction motor, and the elevating speed (v) of the hoisting machine at the rotational speed (n) An estimation circuit;
From the estimated value (m) of the load estimation circuit, the mass (CW) of the counterweight, the rotational speed (n), the lifting speed (v), and the calculated value (Δn) of the acceleration calculating circuit, the counterweight and the load A torque calculation circuit for calculating a running torque (τ ₀₁ ) and acceleration / deceleration required torque (τ ₁₁ ) for (m);
The calculated value (τ ₁₂ ) of the acceleration torque calculating circuit, the set value (τ ₀₂ ) of the torque setting circuit, the calculated value (τ ₀₁ , τ ₁₁ ) of the torque calculating circuit, and the short-term and continuous allowable torque-speed of the induction motor. A speed calculation circuit for obtaining a maximum operable speed command value (N ₀ ^# ) of the induction motor from the characteristics;
A control apparatus for an induction motor, comprising: a speed command value conversion circuit that sets the maximum operable speed command value (N ₀ ^# ) as a new speed command value (N ^# ).

Images