Method for calculating an elevator balance factor and elevator detection system

Abstract

The application discloses a kind of method and detection system of calculating elevator balance coefficient, comprising: the three-phase voltage value and two-phase current value of three-phase motor are collected, and the voltage phase angle value under voltage resultant vector and line voltage effective value in two-phase αβ coordinates are calculated based on three-phase voltage value and two-phase current value;Current phase angle value and line current effective value under current resultant vector;Elevator car operating speed and elevator car running distance are calculated based on voltage phase angle value;Power factor is calculated based on voltage phase angle value and current phase angle value;Elevator car passes through the moment of elevator balance position based on elevator car running distance, and elevator balance coefficient is calculated based on the running data when passing through elevator balance position.The application calculates the moment of elevator car passing through elevator balance position by three-phase voltage value and two-phase current value and the running distance of elevator car, and elevator balance coefficient can be quickly and accurately calculated based on the running data when passing through elevator balance position.

Description

TECHNICAL FIELD

[0001] The present application relates to the elevator technical field, especially to a kind of method for calculating elevator balance coefficient and elevator detection system. BACKGROUND

[0002] Figure 1 The schematic diagram of the structure of the existing elevator transmission system is shown, and most of the current vertical lift is traction elevator, and its transmission system mainly includes traction machine 1 (composed of traction motor and traction sheave), steel wire rope 3, elevator car 4, counterweight (balance weight) 5 and guide wheel 2. The steel wire rope 3 is wound on the traction sheave of the traction machine 1, one end of the steel wire rope 3 is connected to the elevator car 4, and the other end is connected to the counterweight (balance weight) 5. The gravity of the elevator car 4 and the counterweight 5 forms a mutual pressure between the steel wire rope 3 and the traction sheave. When the traction motor operates (rotates), there is a tendency of relative operation between the traction sheave and the steel wire rope 3, generating static friction force, which drives the elevator to run up and down. The gravity of the elevator car 4 and the counterweight 5 is the necessary condition for the static friction force between the elevator steel wire rope 3 and the traction sheave. If the self-weight of the elevator car 4 (the weight of the empty car) is represented by P, the rated load is represented by Q, and the counterweight is represented by W, then the ratio of (W-P) to Q (i.e. the elevator balance coefficient, represented by q) is very important. Too large or too small will cause the risk of slipping (static friction force becomes sliding friction force) between the wire rope and the traction sheave under certain working conditions, which will seriously affect the safe operation of the elevator.

[0003] The traditional elevator balance coefficient detection method (i.e. the provision of GBT 10059) is to measure the current when the elevator car runs up and down with 30%, 40%, 45%, 50% and 60% of the rated load. When the car and the counterweight run to the same horizontal position, the alternating current motor only measures the current, and the direct current motor measures the current and voltage at the same time. Draw the current (or voltage) - load curve to determine the balance coefficient from the intersection of the upward and downward running curves.

[0004] This method requires the elevator to run under different loads, so the detection personnel needs to carry different weights in and out of the elevator car many times. Assuming that the rated load of the elevator is 1000 kg, the 60% load is 600 kg, the workload is large, and the judgment of the balance position (the car and the counterweight run to the same horizontal position) is determined by the detection personnel watching the marks on the steel wire rope, which has a large error. At the same time, the balance data needs to be read from the load-current curve, which also has a large human factor and error, making the calculation of the whole elevator balance coefficient not accurate enough and the overall calculation not fast enough. SUMMARY

[0005] The purpose of the present application is to overcome the deficiencies of the prior art, and the present application provides a method for calculating the elevator balance coefficient and an elevator detection system, which calculates the time when the elevator car passes through the elevator balance position by acquiring three-phase voltage values, two-phase current values and the running distance of the elevator car, and quickly and accurately calculates the elevator balance coefficient based on the running data when passing through the elevator balance position.

[0006] Correspondingly, the present application provides a method for calculating the elevator balance coefficient, which comprises:

[0007] Acquire three-phase voltage values of the three-phase motor, and calculate the voltage phase angle value and the line voltage effective value under the voltage synthesis vector in the two-phase αβ coordinates based on the three-phase voltage values;

[0008] Acquire two-phase current values in the three-phase current of the three-phase motor, and calculate the current phase angle value and the line current effective value under the current synthesis vector in the two-phase αβ coordinates based on the two-phase current values;

[0009] Calculate the elevator car running speed and the elevator car running distance based on the voltage phase angle value;

[0010] Calculate the power factor based on the voltage phase angle value and the current phase angle value;

[0011] Identify the time when the elevator car passes through the elevator balance position based on the car running distance, and calculate the elevator balance coefficient based on the elevator car running speed, the power factor, the line voltage effective value and the line current effective value when the elevator car passes through the elevator balance position.

[0012] The calculation of the elevator car running speed and the elevator car running distance based on the voltage phase angle value comprises:

[0013] Calculate the voltage phase angle increment value at time t based on the voltage phase angle value at time t and the voltage phase angle value of the previous sampling period at time t;

[0014] Calculate the elevator car running speed at time t based on the rated frequency of the elevator motor, the rated speed of the elevator car and the voltage phase angle increment value;

[0015] Calculate the elevator car running distance based on the integral of speed with respect to time.

[0016] The calculation of the elevator car running speed at time t based on the rated frequency of the elevator motor, the rated speed of the elevator car and the voltage phase angle increment value comprises:

[0017] Calculate the angular frequency at time t based on the voltage phase angle increment value;

[0018] The elevator car running speed Va(t) at time t is calculated based on the relationship between the voltage frequency and the angular frequency of the voltage vector, where:

[0019] Va(t)=Vr*fa(t) / fr=(1 / T*Δθ(t) / 2π)*Vr* / fr;

[0020] Va(t) is the speed of the elevator at time t, Vr is the rated speed of the elevator, fr is the rated frequency of the elevator, Δθ(t) is the voltage phase angle increment at time t, fa(t) is the frequency of the voltage at time t, ω(t) is the angular frequency of the voltage vector at time t, ω(t) = 1 / T*Δθ(t), T is the sampling period, and fa(t) = ω(t) / 2π.

[0021] The calculation of the elevator car travel distance based on the integral of speed over time includes:

[0022] The elevator car travel distance Sa is calculated based on the integral of speed over time, where:

[0023] Sa=∫Va(t)dt=∫((1 / T*Δθ(t) / 2π)*Vr* / fr)dt;

[0024] Where Sa is the elevator running distance, Vr is the rated speed of the elevator, fr is the rated frequency of the elevator, T is the sampling period, and Δθ(t) is the voltage phase angle increment at time t.

[0025] The elevator balance coefficient is calculated based on the elevator car running speed, power factor, line voltage effective value and line current effective value when the elevator car passes through the elevator balance position, including:

[0026] Calculating a motor phase resistance based on the power factor, the line voltage effective value, and the line current effective value when the elevator car passes through the elevator equilibrium position;

[0027] Calculating an upward mechanical power of the elevator car and a downward mechanical power of the elevator car based on the motor phase resistance, the power factor when the elevator car passes through the elevator equilibrium position, the line voltage effective value, and the line current effective value;

[0028] An elevator balance coefficient is calculated based on the upward mechanical power of the elevator car, the downward mechanical power of the elevator car, and the elevator car running speed when the elevator car passes through the elevator balance position.

[0029] The calculating of the motor phase resistance based on the power factor, the line voltage effective value, and the line current effective value when the elevator car passes through the elevator equilibrium position includes:

[0030] Obtain the running data and down running data of the elevator car when it passes the elevator equilibrium position. The running data includes: the running line voltage Us on the motor, the running line current Is on the motor, and the running power factor The running data include: motor running line voltage Ux, motor running line current Ix, running power factor

[0031] The motor phase resistance Rs is calculated based on the upper running data and the lower running data, where:

[0032]

[0033] Rs is the motor phase resistance, and Ef is the elevator transmission efficiency.

[0034] The calculating of the upward mechanical power of the elevator car and the downward mechanical power of the elevator car based on the motor phase resistance, the power factor when the elevator car passes through the elevator equilibrium position, the line voltage effective value, and the line current effective value includes:

[0035] The downward mechanical power of the elevator car is calculated based on the motor phase resistance, the power factor when the elevator car passes through the elevator equilibrium position, the line voltage effective value, and the line current effective value:

[0036]

[0037] Among them, Ux is the motor running line voltage, Ix is the motor running line current, is the down-running power factor, Nx is the down-running mechanical power of the elevator car, Ef is the elevator transmission efficiency, and Rs is the motor phase resistance;

[0038] The upward mechanical power of the elevator car is calculated based on the motor phase resistance, the power factor when the elevator car passes through the elevator equilibrium position, the line voltage effective value, and the line current effective value:

[0039]

[0040] Among them, Us is the line voltage on the motor, Is is the line current on the motor, is the operating power factor, Ns is the upward mechanical power of the elevator car, Ef is the elevator transmission efficiency, and Rs is the motor phase resistance.

[0041] The elevator balance coefficient is calculated based on the upward mechanical power of the elevator car, the downward mechanical power of the elevator car, and the elevator car running speed when the elevator car passes through the elevator balance position, including:

[0042] The calculation formula of the elevator balance coefficient is:

[0043] q=(Ns*Vx+Nx*Vs) / (2*Vs*Vx*gn*Q);

[0044] Among them, q is the elevator balance coefficient, Ns is the upward mechanical power of the elevator car, Nx is the downward mechanical power of the elevator car, Q is the rated load of the elevator, gn is the gravitational acceleration constant, Vs is the elevator speed when the elevator car passes the elevator equilibrium position, and Vx is the elevator speed when the elevator car passes the elevator equilibrium position.

[0045] The method further includes: displaying elevator operating status parameters, wherein the elevator operating status parameters include: elevator car operating speed, power factor, motor phase resistance, elevator car upward mechanical power, elevator car downward mechanical power, and elevator balance coefficient.

[0046] Correspondingly, the present invention also proposes an elevator detection system, which is used to execute any of the above methods.

[0047] The present invention collects the three-phase voltage values ​​of a three-phase motor and the current values ​​of two of the three-phase currents. Based on the voltage composite vector in the two-phase αβ coordinates, the voltage phase angle, line voltage RMS, current phase angle, and line current RMS are obtained. The data from these composite vectors can be used to calculate the elevator car speed and distance required in real time for the elevator balance coefficient. The distance can be used to accurately identify the moment when the elevator car passes through the elevator equilibrium position. The elevator balance coefficient is then calculated based on the elevator car speed, power factor, line voltage RMS, and line current RMS when the elevator car passes through the equilibrium position. These calculations are all performed based on the voltage and current values ​​of the three-phase motor. The entire calculation method can be performed in the elevator's no-load operating mode, avoiding many human factors and eliminating the need for multiple load adjustments by testers. The entire calculation process calculates elevator operating data passing through the equilibrium position based on the real-time collected voltage and current values, making subsequent calculation of the elevator balance coefficient more accurate. The entire elevator balance coefficient calculation can be completed in real time during elevator operation, making the calculation of the entire elevator balance coefficient faster. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0049] Figure 1 It is a structural diagram of an existing elevator transmission system;

[0050] Figure 2 is a flow chart of a method for calculating an elevator balance coefficient in an embodiment of the present invention;

[0051] Figure 3 is a voltage synthesis vector diagram of the three-phase voltage in the UVW coordinate system in an embodiment of the present invention;

[0052] Figure 4 is a voltage synthesis vector diagram of the three-phase voltage in the αβ coordinate system in an embodiment of the present invention;

[0053] Figure 5 It is a structural diagram of an elevator detection system in an embodiment of the present invention. DETAILED DESCRIPTION

[0054] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0055] The method for calculating the elevator balance coefficient involved in an embodiment of the present invention includes: collecting the three-phase voltage values ​​of the three-phase motor, and calculating the voltage phase angle value and the line voltage effective value under the voltage synthesis vector in the two-phase αβ coordinates based on the three-phase voltage values; collecting the two-phase current values ​​of the three-phase current of the three-phase motor, and calculating the current phase angle value and the line current effective value under the current synthesis vector in the two-phase αβ coordinates based on the two-phase current values; calculating the elevator car running speed and the elevator car running distance based on the voltage phase angle value; calculating the power factor based on the voltage phase angle value and the current phase angle value; identifying the moment when the elevator car passes the elevator balance position based on the car running distance, and calculating the elevator balance coefficient based on the elevator car running speed, power factor, line voltage effective value and line current effective value when the elevator car passes the elevator balance position.

[0056] The embodiments of the present invention collect the three-phase voltage values ​​of a three-phase motor and the current values ​​of two of the three-phase currents. Based on the voltage composite vector in the two-phase αβ coordinates, the voltage phase angle value, the line voltage effective value, the current phase angle value, and the line current effective value are obtained. The data from these composite vectors can be used to calculate the elevator car speed and distance traveled in real time required for the elevator balance coefficient. The distance traveled can accurately identify the moment when the elevator car passes through the elevator equilibrium position. The elevator balance coefficient is then calculated based on the elevator car speed, power factor, line voltage effective value, and line current effective value when the elevator car passes through the elevator equilibrium position. These calculation processes are all based on the voltage and current values ​​of the three-phase motor. The entire calculation method can be completed in the elevator's no-load operating mode, avoiding many human factors and eliminating the need for multiple load adjustments by testers. The entire calculation process calculates elevator operation data passing through the equilibrium position based on the real-time collected voltage and current values, making subsequent calculation of the elevator balance coefficient more accurate. The entire elevator balance coefficient calculation can be completed in real time during elevator operation, making the calculation of the entire elevator balance coefficient faster.

[0057] The method in the embodiment of the present invention enables elevator inspectors to quickly, accurately, and easily detect the elevator balance coefficient when the elevator is unloaded, and record and save the detection data through a mobile phone APP, greatly reducing the labor intensity of the inspectors and ensuring the safe operation of the elevator.

[0058] According to GBT 7588.1, the elevator balance coefficient is defined as the amount by which the counterweight balances the rated load, that is:

[0059] q=(WP) / Q;

[0060] Among them, q is the balance coefficient, W is the counterweight; P is the weight of the car (i.e. the weight of the empty car), and Q is the rated load.

[0061] Without considering the transmission efficiency of the elevator (assuming the transmission efficiency is 100%), the traction force of the car (the static friction between the wire rope and the traction sheave) when the elevator is running upward and downward at a constant speed is equal, and is equal to the weight difference between the counterweight and the empty car, that is:

[0062] Fs=Fx=(WP)*gn;

[0063] Among them, gn is the acceleration due to gravity, which is 9.81m / s 2 , Fs is the upward uniform speed running traction force, and Fx is the downward uniform speed running traction force.

[0064] According to the mechanical power formula N = F * V, where N is power, F is the force, and V is the speed in the direction of the force. When the elevator is moving upward at a constant speed, its mechanical power is Ns = Fs * Vs, where Ns is the upward mechanical power of the elevator car, Fs is the upward traction force, and Vs is the upward speed of the elevator car. Then:

[0065] Fs=Ns / Vs;

[0066] When the elevator runs downward at a constant speed, its mechanical power is Nx = Fx * Vx (where Nx is the downward mechanical power of the elevator car, Fx is the downward traction force, and Vx is the downward speed of the elevator car).

[0067] Fx=Nx / Vx;

[0068] Combining the formulas Fs=Fx=(WP)*gn, Fs=Ns / Vs, and Fx=Nx / Vx, we obtain:

[0069] (Fs+Fx) / 2=((Ns / Vs)+(Nx / Vx)) / 2=(WP)*gn:

[0070] (WP)=((Ns / Vs)+(Nx / Vx)) / 2*gn=(Ns*Vx+Nx*Vs) / 2*Vs*Vx*gn;

[0071] q=(WP) / Q=(Ns*Vx+Nx*Vs) / (2*Vs*Vx*gn*Q);

[0072] Where: q is the elevator balance coefficient, Ns is the upward mechanical power of the elevator car, Nx is the downward mechanical power of the elevator car, Vs is the upward speed of the elevator car, Vx is the downward speed of the elevator car, gn is the acceleration of gravity, which is 9.81m / s 2 , Q is the rated load capacity of the elevator.

[0073] In summary, the elevator balance coefficient is solely related to the mechanical power, speed, rated load, and gravitational acceleration of the elevator car when the elevator, unloaded, moves upward and downward at a constant speed through the equilibrium position (the midpoint of the elevator's hoisting height). While the motor's electrical power is relatively easy to measure, the mechanical power is more difficult to measure and calculate. Because the phase angles of the current and voltage vectors are not identical when the motor is running, the measured apparent power cannot be used as the mechanical power to calculate the elevator balance coefficient. This is especially true when the elevator motor has low power, as its phase resistance is relatively high. Heat losses due to the motor's phase resistance (copper losses) account for a significant proportion of the motor's input power and cannot be ignored. Furthermore, the power factor of asynchronous motors is relatively low, at approximately 85%. Therefore, the power factor significantly influences the calculation of the elevator's mechanical power. Therefore, when the elevator no-load power method is used to detect the elevator balance coefficient, it is very important to detect the motor phase resistance and power factor. The present invention can detect the motor current and motor voltage when the elevator goes up and down through the elevator balance position, and then calculate the motor phase resistance, power factor, elevator car running speed, etc., and then calculate the mechanical power of the elevator car when it goes up and down through the elevator balance position through an algorithm, thereby calculating the elevator balance coefficient.

[0074] Specifically, Figure 2 A flow chart of a method for calculating an elevator balance coefficient according to an embodiment of the present invention is shown. The method includes the following steps:

[0075] It should be noted that since the elevator motor is a three-phase balanced load (i.e., the effective values ​​of the three-phase currents or phase voltages are equal when the motor is running), the present invention adopts a vector transformation algorithm when calculating current and voltage to speed up the detection time and simplify the calculation.

[0076] S101, collecting three-phase voltage values ​​of a three-phase motor;

[0077] Here, collecting the three-phase voltage value of the elevator motor at time t includes: detecting the three-phase input power of the elevator motor through a voltage probe; performing proportional and filtering processing on the three-phase input power; and obtaining the three-phase voltage value based on analog-to-digital sampling conversion of the three-phase input power.

[0078] The present invention uses three high-voltage voltage probes, coupled with corresponding hardware circuits, as elevator motor voltage detection units, respectively for detecting the U-phase, V-phase, and W-phase voltages of the elevator motor. The CPU samples the voltages in real time, obtaining the instantaneous values ​​of the motor's U-phase, V-phase, and W-phase voltages. These instantaneous values ​​are then transformed using a Clark transform, converting the motor's composite voltage vector (three-phase coordinates (U, V, W)) into a composite voltage vector (two-phase coordinates (α, β)). An algorithm then calculates the effective value of the motor's line voltage. This algorithm can calculate the motor's line voltage effective value in a relatively short time (100 μs).

[0079] S102, voltage Clark transformation;

[0080] Specifically, the voltage acquisition method for three-phase motors uses a voltage probe to detect the three-phase input power supply (U, V, and W) of the elevator motor. The three-phase power supply undergoes scaling and filtering, and is sampled by the CPU's analog-to-digital circuit (ADC) (assuming a sampling period of 100 μs). This transform yields the instantaneous voltage values: Uu, Uv, and Uw (Uu represents the instantaneous voltage value of phase U, Uv represents the instantaneous voltage value of phase V, and Uw represents the instantaneous voltage value of phase W). These values ​​represent the amplitude of the voltage vector at that moment in the three-phase coordinate system. Because the magnitude and direction of the instantaneous voltage values ​​constantly change, calculation and processing are difficult. Therefore, the voltage vectors are synthesized and then transformed. Because the synthesized voltage vector remains unchanged before and after the transformation (its magnitude, direction, and angular frequency remain unchanged), calculating and processing the synthesized and transformed voltage vectors is equivalent to calculating and processing the instantaneous voltage.

[0081] Here, the three-phase voltage values ​​of the three-phase motor at time t are collected, and based on the three-phase voltage values, the voltage phase angle value and the line voltage effective value under the voltage synthesis vector in the two-phase αβ coordinates are calculated.

[0082] That is, the three-phase voltage value is subjected to Clark transformation, and the transformation algorithm is as follows:

[0083]

[0084] The voltage synthesis vector before and after the transformation is as follows Figure 3 and Figure 4 As shown, Figure 3 is the voltage synthesis vector diagram in the three-phase UVW coordinates in the embodiment of the present invention, Figure 4 It is a two-phase αβ coordinate voltage synthesis vector diagram in an embodiment of the present invention, wherein Ut is the synthesis vector of the three-phase voltage of the motor at time t.

[0085] S103, calculating the voltage phase angle value;

[0086] Here, the three-phase voltage values ​​are subjected to Clark transformation to obtain the voltage synthesis vector in the two-phase αβ coordinates, and the voltage phase angle value at time t is obtained, which includes:

[0087] Assume that Ut is the voltage synthesis vector after vector transformation. After the three-phase voltage value is subjected to Clark transformation, in the αβ coordinates, the projection on the α axis is Utα, and the projection on the β axis is Utβ. Then

[0088]

[0089] Among them, θ is the phase angle, Utβ is the projection of the voltage synthesis vector at time t on the β axis, and Utα is the projection of the voltage synthesis quantity at time t on the α axis.

[0090] Furthermore, the phase angle of the voltage synthesis vector at time t is:

[0091]

[0092] Among them, θ is the phase angle, Utβ is the projection of the voltage synthesis vector at time t on the β axis, and Utα is the projection of the voltage synthesis quantity at time t on the α axis.

[0093] S104, calculating the voltage phase angle increment value;

[0094] Specifically, the voltage phase angle increment calculation module is a calculation module for synthesizing the voltage vector phase angle increment after the voltage vector passes through one sampling cycle. Assuming that the original voltage vector phase angle is θ, and after one sampling cycle, its phase angle is θ1, then the phase angle increment Δθ = θ1 - θ can be used to calculate the phase angle increment.

[0095] That is, the voltage phase angle increment value at time t is calculated based on the voltage phase angle value at time t and the voltage phase angle value of the previous sampling period at time t, including:

[0096]

[0097] Among them, Δθ(t) is the voltage phase angle increment at time t, Ut1β is the projection of the voltage composite vector on the β-axis at time t1, Ut1α is the projection of the voltage composite vector on the α-axis at time t1, Utβ is the projection of the voltage composite vector on the β-axis at time t, and Utα is the projection of the voltage composite quantity on the α-axis.

[0098] S105, calculating the voltage angular frequency value;

[0099] The voltage angular frequency calculation here is that its input is 1 sampling period T (here T is set to 100μs), the voltage phase angle increment △θ, the phase angle increment within 1s is the angular frequency, here T is 0.0001s, so the angular frequency value of the motor voltage can be calculated, and the angular frequency at time t is:

[0100] ω(t)=Δθ(t) / T, where ω(t) is the angular frequency of the voltage at time t, and Δθ(t) is the voltage phase angle increment at time t.

[0101] S106. Calculate the elevator car running speed;

[0102] Specifically, calculating the elevator car running speed at time t based on the rated frequency of the elevator motor, the rated speed of the elevator car, and the voltage phase angle increment value includes: calculating the elevator car running speed Va(t) at time t based on the relationship between the voltage frequency and the angular frequency of the voltage vector, wherein:

[0103] Va(t)=Vr*fa(t) / fr=(1 / T*Δθ(t) / 2π)*Vr* / fr;

[0104] Va(t) is the speed of the elevator at time t, Vr is the rated speed of the elevator, fr is the rated frequency of the elevator, Δθ(t) is the voltage phase angle increment at time t, fa(t) is the frequency of the voltage at time t, ω(t) is the angular frequency of the voltage vector at time t, ω(t) = 1 / T*Δθ(t), T is the sampling period, and fa(t) = ω(t) / 2π.

[0105] S107. Calculate the elevator car travel distance;

[0106] Specifically, the travel distance Sa of the elevator car is calculated based on the integral of speed over time, where:

[0107] Sa=∫ Va(t)dt=∫((1 / T*Δθ(t) / 2π)*Vr* / fr)dt;

[0108] Where Sa is the elevator running distance, Vr is the rated speed of the elevator, fr is the rated frequency of the elevator, T is the sampling period, and Δθ(t) is the voltage phase angle increment at time t.

[0109] It should be noted that calculating the elevator car running speed and the elevator car running distance based on the voltage phase angle value here includes: calculating the voltage phase angle increment at time t based on the voltage phase angle value at time t and the voltage phase angle value in the sampling period before time t; calculating the elevator car running speed at time t based on the rated frequency of the elevator motor, the rated speed of the elevator car, and the voltage phase angle increment; and calculating the elevator car running distance based on the integral of the speed over time. That is, this is achieved here through steps S103, S104, S105, S106, and S107.

[0110] S108, calculating the line voltage value;

[0111] It should be noted that here the effective value of the line voltage is calculated. In the voltage αβ coordinates, the modulus of the synthetic voltage vector is the effective value of the voltage, that is, the effective value of the voltage is:

[0112]

[0113] Where U is the effective value of the motor voltage, that is, the line voltage value, Uα is the projection of the voltage synthesis vector on the α-axis, and Uβ is the projection of the voltage synthesis vector on the β-axis.

[0114] S109, collecting two-phase current values ​​among the three-phase currents of the three-phase motor;

[0115] The present invention uses two high-precision Hall effect current sensors as elevator motor current detection units. These sensors use the current values ​​of two of the three-phase currents to form the composite current vector in the two-phase αβ coordinates. Specifically, two high-precision Hall effect current sensors are used to detect the U-phase and V-phase currents of the elevator motor, respectively. The CPU samples the current sensors in real time, obtaining the instantaneous values ​​of the motor's U-phase and V-phase currents. These instantaneous values ​​are then subjected to a Clark transform, converting the composite motor current vector in the three-phase coordinates (U, V, W) into the composite motor current vector in the two-phase coordinates (α, β). An algorithm is then used to calculate the effective value of the motor's line current. This algorithm can calculate the effective value of the motor's line current within a relatively short detection time (sampling the current values ​​of two of the three-phase currents once every 100 μs).

[0116] S110, current Clark transformation;

[0117] In the specific implementation process of the present invention, the two-phase current values ​​are subjected to Clark transformation to obtain the current composite vector in the two-phase αβ coordinates. That is, the instantaneous value is subjected to Clark transformation to convert the motor composite current vector of the three-phase coordinates (U, V, W) into the motor current composite vector of the two-phase coordinates (α, β). Then, through the algorithm, the current can be sampled only in the U and V phases. The Clark transformation current expression of the two-phase coordinates can be:

[0118]

[0119] Among them, Iα is the α-phase current after Clark transformation, Iβ is the β-phase current after Clark transformation, IU is the U-phase current in the three-phase current, and IV is the V-phase current in the three-phase current. The effective value of the motor line current is calculated. This algorithm can calculate the effective value of the motor line current in a relatively short time (100μs), that is, obtain the current synthesis vector.

[0120] S111, calculating the line current value;

[0121] It should be noted that in the current αβ coordinates, the modulus of the synthetic current vector is the effective value of the current, that is, the effective value of the current, that is, the line current value is:

[0122]

[0123] Where I is the effective value of the motor voltage, Iα is the projection of the current resultant vector on the α-axis, and Iβ is the projection of the current resultant vector on the β-axis.

[0124] S112, calculating the current phase angle value;

[0125] In the specific implementation process of the present invention, set θ i is the phase angle of the current vector at time t, Itα is the projection of the current vector on the α axis at time t, Itβ is the projection of the current vector on the β axis at time t,

[0126] Specifically, the current phase angle value at time t is obtained by calculation based on the current synthesis vector, and It is set as the current synthesis vector after vector transformation. After the three-phase current value is subjected to Clark transformation to obtain two phases, in the αβ coordinates, the projection on the α axis is Itα, and the projection on the β axis is Itβ. Then

[0127]

[0128] Set θ i is the phase angle of the current vector at time t, Itα is the projection of the current vector on the α axis at time t, Itβ is the projection of the current vector on the β axis at time t,

[0129] S113. Calculate the power factor;

[0130] In the specific implementation process of the present invention, the power factor at time t is calculated based on the voltage phase angle value and the current phase angle value, including: setting cosφ as the power factor, θ as the voltage phase angle, θ i is the current phase angle;

[0131]

[0132] Among them, Utα and Utβ are the projections of the motor voltage synthesis vector on the α-axis and β-axis in the two-phase αβ coordinates, and Itα and Itβ are the projections of the motor current synthesis vector on the α-axis and β-axis in the two-phase αβ coordinates.

[0133] Specifically, cosφ is set as the power factor, θ is the voltage phase angle, and θ i is the current phase angle;

[0134] cosφ=cos(θ-θ i );

[0135] Right now

[0136] Among them, Utα and Utβ are the projections of the motor voltage synthesis vector on the α-axis and β-axis in the two-phase αβ coordinates, and Itα and Itβ are the projections of the motor current synthesis vector on the α-axis and β-axis in the two-phase αβ coordinates.

[0137] When θ and θ i When the current and voltage are the same, there is no phase difference between the current and voltage, the apparent power is the useful power, and the power factor is 1. When the current and voltage phase angles are different, the product of the current projection in the voltage direction and the voltage is the useful work.

[0138] It should be noted that in steps S101 to S113, as the elevator balance coefficient detection is started, the three-phase voltage value and the three-phase current value can be collected at any time during the elevator balance coefficient detection process. As the three-phase voltage value and the two-phase current values ​​of the three-phase current are continuously collected, they can be continuously converted into the voltage phase angle value, line voltage value, line current value, and current phase angle value at the current moment. Then, the real-time elevator car running speed and car running distance can be calculated through the real-time voltage phase angle value, and the real-time power factor can be calculated from the current phase angle value and the voltage phase angle value. These real-time data need to be stored locally, and the elevator car running speed, line voltage value, line current value, and power factor when the elevator car passes the balance position need to participate in the calculation process of the elevator balance coefficient.

[0139] S114, determining the elevator equilibrium position;

[0140] Specifically, here, whether the elevator reaches the elevator equilibrium position is determined by the elevator car running distance, that is, the elevator operating parameters at that moment are recorded by reaching the elevator equilibrium position. If it is recognized that the elevator car passes the elevator equilibrium position, the process proceeds to S115. If not, the car running distance is continued to be calculated until it is recognized that the elevator car passes the elevator equilibrium position.

[0141] When the elevator car runs from the bottom floor to the top floor, the distance the elevator car runs from the top floor to the equilibrium position is obtained by calculating the distance the elevator car runs, and dividing the distance by 2. Alternatively, when the elevator car runs from the top floor to the bottom floor, the distance the elevator car runs from the bottom floor to the equilibrium position is obtained by calculating the distance the elevator car runs, and dividing the distance by 2.

[0142] It should be noted that here, whether the elevator car passes through the elevator equilibrium position is identified based on the elevator car running distance, that is, whether the elevator car reaches the equilibrium position during operation is judged by the calculated elevator car running distance, thereby calculating the moment when the upper running state passes through the equilibrium position and the moment when the lower running state passes through the equilibrium position, and at the same time recording the elevator operating parameters needed at these two moments, such as the elevator car running speed, power factor, line voltage effective value and line current effective value when the elevator car passes the elevator equilibrium position, etc. These elevator operating parameters need to participate in the calculation of the motor phase resistance, the elevator car's upward mechanical power and the elevator car's downward mechanical power, and the elevator balance coefficient.

[0143] S115, calculating the motor phase resistance;

[0144] It should be noted that the calculation of motor phase resistance is completed by calculating the effective value of line voltage, effective value of line current, elevator parameters, and power factor. When the elevator is running downward without load, the motor draws electrical energy from the grid and converts it into mechanical energy to drive the elevator. Assuming that the motor iron loss (eddy current loss) is ignored, the relationship between electrical power and mechanical power is as follows:

[0145]

[0146] Among them, Ux is the motor running line voltage, Ix is the motor running line current, is the lower operating power factor, E is the motor back electromotive force, Ef is the elevator transmission efficiency, and Rs is the motor phase resistance.

[0147] Simplifying the above formula, we get:

[0148]

[0149] When the elevator is running upward without load, the motor is in a generating braking state, and mechanical energy drives the motor to generate electricity. Assuming that the motor iron loss (eddy current loss) is negligible, the relationship between electric power and mechanical power is as follows:

[0150]

[0151] Among them, Us is the line voltage on the motor, Is is the line current on the motor, is the upper operating power factor, E is the motor electromotive force (for the same motor, the up and down speeds are the same, so its value is equal to the back electromotive force), Ef is the elevator transmission efficiency (for the same elevator, the up and down speeds are the same, the efficiency is the same), and Rs is the motor phase resistance.

[0152] Furthermore, the above formula is simplified to obtain:

[0153]

[0154] Formula Perform the transformation and get:

[0155]

[0156] Formula Transform and multiply both sides of the equation by Ef 2 ,get:

[0157]

[0158] By the formula and formula Adding them together, we get:

[0159]

[0160] Right now;

[0161]

[0162] Furthermore, the elevator transmission efficiency Ef is set based on the elevator parameters, and the phase resistance of the elevator system motor can be calculated by combining the upper running line voltage Us of the motor, the upper running line current Is of the motor, the lower running line voltage Ux of the motor, and the lower running line current Ix of the motor.

[0163] S116. Calculate the upward mechanical power of the elevator car and the downward mechanical power of the elevator car;

[0164] It should be noted that the calculation of the upward mechanical power of the elevator car and the downward mechanical power of the elevator car here needs to be combined with the elevator parameters, motor phase resistance, line current RMS, line voltage RMS, power factor, etc. The above parameters are all elevator operating status parameters when the elevator car passes through the equilibrium position, that is, the line current RMS, line voltage RMS, power factor, etc. must be real-time parameters when the elevator car is in an over-balanced position.

[0165] When the elevator is running downward without load, the motor absorbs electrical energy from the grid and converts it into mechanical energy to drive the elevator. Assuming that the motor iron loss (eddy current loss) is negligible, the relationship between electrical power and mechanical power is as follows:

[0166]

[0167] Based on the above formula deformation, we can get:

[0168]

[0169] Among them, Ux is the motor running line voltage, Ix is the motor running line current, is the downward operating power factor, Nx is the downward mechanical power of the elevator car, Ef is the elevator transmission efficiency, and Rs is the motor phase resistance.

[0170] When the elevator is running upward without load, the motor is in a generating braking state, and mechanical energy drives the motor to generate electricity. Assuming that the motor iron loss (eddy current loss) is negligible, the relationship between electric power and mechanical power is as follows:

[0171]

[0172] Based on the above formula deformation, we can get:

[0173]

[0174] Among them, Us is the line voltage on the motor, Is is the line current on the motor, is the operating power factor, Ns is the upward mechanical power of the elevator car, Ef is the elevator transmission efficiency, and Rs is the motor phase resistance.

[0175] S117. Obtaining the running speed of the elevator car when the elevator car passes through the elevator equilibrium position;

[0176] It should be noted that the elevator car running speed here is generated by step S106. The elevator car running speed is generated in real time during the elevator balance coefficient detection process. Only the elevator car running speed when the elevator car passes the elevator balance position is involved in the calculation process of the elevator balance coefficient.

[0177] S118. Calculate the elevator balance coefficient.

[0178] It should be noted that the calculation of the elevator balance coefficient here needs to be combined with the elevator parameters, the upward mechanical power of the elevator car, the downward mechanical power of the elevator car, and the elevator car running speed when the elevator car passes the elevator balance position. The calculation formula of the elevator balance coefficient is:

[0179] q=(Ns*Vx+Nx*Vs) / (2*Vs*Vx*gn*Q);

[0180] Among them, q is the elevator balance coefficient, Ns is the upward mechanical power of the elevator car, Nx is the downward mechanical power of the elevator car, Q is the rated load of the elevator, gn is the gravitational acceleration constant, Vs is the elevator speed when the elevator car passes the elevator equilibrium position, and Vx is the elevator speed when the elevator car passes the elevator equilibrium position.

[0181] Where Ns and Nx are calculated in step S116, Vs and Vx are calculated in step S106, and gn is a constant equal to 9.81 m / s 2 , Q is the rated load capacity of the elevator set by the elevator parameters.

[0182] It should be noted that the calculation of the elevator balance coefficient based on the elevator car running speed, power factor, line voltage RMS, and line current RMS when the elevator car passes through the elevator equilibrium position includes: calculating the motor phase resistance based on the power factor, line voltage RMS, and line current RMS when the elevator car passes through the elevator equilibrium position; calculating the elevator car's upward mechanical power and the elevator car's downward mechanical power based on the motor phase resistance, the power factor, line voltage RMS, and line current RMS when the elevator car passes through the elevator equilibrium position; and calculating the elevator balance coefficient based on the elevator car's upward mechanical power, the elevator car's downward mechanical power, and the elevator car running speed when the elevator car passes through the elevator equilibrium position. That is, the calculation of the elevator balance coefficient based on the elevator car running speed, power factor, line voltage RMS, and line current RMS when the elevator car passes through the elevator equilibrium position is completed by steps SS114-S118 together.

[0183] It should be noted that this method also includes displaying elevator operating status parameters, including elevator car operating speed, power factor, motor phase resistance, elevator car upward mechanical power, elevator car downward mechanical power, and elevator balance coefficient. In other words, the detection device based on this method can display relevant power supply operating status parameters in real time, thereby providing real-time information on the calculation status of the entire elevator balance coefficient.

[0184] In summary, the elevator balance coefficient is solely dependent on the mechanical power, speed, rated load, and gravitational acceleration of the elevator car when the elevator, unloaded, moves upward and downward at a constant speed through the equilibrium position (the midpoint of the elevator's lift height). While the motor's electrical power is relatively easy to measure, the mechanical power is more difficult to measure and calculate. Because the phase angles of the current and voltage vectors are not identical when the motor is running, the measured apparent power cannot be used as the mechanical power to calculate the elevator balance coefficient. This is especially true when the elevator motor has low power, as its phase resistance is relatively high. Heat losses due to phase resistance (copper losses) account for a significant proportion of the motor's input power and cannot be ignored. Furthermore, the power factor of asynchronous motors is relatively low, at approximately 85%. Therefore, the power factor significantly influences the calculation of the elevator's mechanical power. Therefore, when the elevator no-load power method is used to detect the elevator balance coefficient, it is very important to detect the phase resistance and power factor of the motor. The embodiment of the present invention obtains the current and voltage of the motor by detecting when the elevator passes through the elevator balance position at a uniform speed up and down, and then calculates the phase resistance, power factor, speed, etc. of the motor. Then, an algorithm is used to calculate the mechanical power when the elevator car passes through the elevator balance position at a uniform speed up and down, thereby calculating the elevator balance coefficient.

[0185] Accordingly, the present invention also proposes an elevator detection system, which is used to execute the above method for calculating the elevator balance coefficient. The specific implementation process of this method can be found in Figures 2 to 4 Instructions in .

[0186] Specifically, Figure 5 FIG. 1 is a schematic diagram showing the structure of an elevator detection system according to an embodiment of the present invention, wherein the elevator detection system includes:

[0187] The voltage data calculation module 10 is used to collect the three-phase voltage values ​​of the three-phase motor, and calculate the voltage phase angle value and the line voltage effective value under the voltage synthesis vector in the two-phase αβ coordinates based on the three-phase voltage values.

[0188] The current data calculation module 20 is used to collect two-phase current values ​​of the three-phase current of the three-phase motor, and calculate the current phase angle value and line current effective value under the current synthesis vector in the two-phase αβ coordinates based on the two-phase current values.

[0189] Running distance calculation module 30: calculates the elevator car running speed and the elevator car running distance based on the voltage phase angle value;

[0190] A power factor calculation module 40 is configured to calculate a power factor based on the voltage phase angle value and the current phase angle value.

[0191] The balance coefficient calculation module 50 identifies the moment when the elevator car passes the elevator equilibrium position based on the elevator car running distance, and calculates the elevator balance coefficient based on the elevator car running speed, power factor, line voltage effective value and line current effective value when the elevator car passes the elevator equilibrium position.

[0192] Calculating the elevator car running speed and the elevator car running distance based on the voltage phase angle value includes:

[0193] Calculate the voltage phase angle increment value at time t based on the voltage phase angle value at time t and the voltage phase angle value of the previous sampling period at time t;

[0194] Calculating the elevator car running speed at time t based on the rated frequency of the elevator motor, the rated speed of the elevator car, and the voltage phase angle increment value;

[0195] The distance traveled by the elevator car is calculated based on the integral of the speed over time.

[0196] The step of calculating the elevator car running speed at time t based on the rated frequency of the elevator motor, the rated speed of the elevator car, and the voltage phase angle increment value includes:

[0197] Calculate the angular frequency at time t based on the voltage phase angle increment;

[0198] The elevator car running speed Va(t) at time t is calculated based on the relationship between the voltage frequency and the angular frequency of the voltage vector, where:

[0199] Va(t)=Vr*fa(t) / fr=(1 / T*Δθ(t) / 2π)*Vr* / fr;

[0200] Va(t) is the speed of the elevator at time t, Vr is the rated speed of the elevator, fr is the rated frequency of the elevator, Δθ(t) is the voltage phase angle increment at time t, fa(t) is the frequency of the voltage at time t, ω(t) is the angular frequency of the voltage vector at time t, ω(t) = 1 / T*Δθ(t), T is the sampling period, and fa(t) = ω(t) / 2π.

[0201] Calculating the elevator car running distance based on the integral of speed over time includes: calculating the elevator car running distance Sa based on the integral of speed over time, wherein:

[0202] Sa=∫Va(t)dt=∫((1 / T*Δθ(t) / 2π)*Vr* / fr)dt;

[0203] Where Sa is the elevator running distance, Vr is the rated speed of the elevator, fr is the rated frequency of the elevator, T is the sampling period, and Δθ(t) is the voltage phase angle increment at time t.

[0204] The elevator balance coefficient is calculated based on the elevator car running speed, power factor, line voltage effective value and line current effective value when the elevator car passes through the elevator balance position, including:

[0205] Calculating a motor phase resistance based on the power factor, the line voltage effective value, and the line current effective value when the elevator car passes through the elevator equilibrium position;

[0206] Calculating an upward mechanical power of the elevator car and a downward mechanical power of the elevator car based on the motor phase resistance, the power factor when the elevator car passes through the elevator equilibrium position, the line voltage effective value, and the line current effective value;

[0207] An elevator balance coefficient is calculated based on the upward mechanical power of the elevator car, the downward mechanical power of the elevator car, and the elevator car running speed when the elevator car passes through the elevator balance position.

[0208] The calculating of the motor phase resistance based on the power factor, the line voltage effective value, and the line current effective value when the elevator car passes through the elevator equilibrium position includes:

[0209] Obtain the running data and down running data of the elevator car when it passes the elevator equilibrium position. The running data includes: the running line voltage Us on the motor, the running line current Is on the motor, and the running power factor The running data include: motor running line voltage Ux, motor running line current Ix, running power factor

[0210] The motor phase resistance Rs is calculated based on the upper running data and the lower running data, where:

[0211]

[0212] Rs is the motor phase resistance, and Ef is the elevator transmission efficiency.

[0213] The calculating of the upward mechanical power of the elevator car and the downward mechanical power of the elevator car based on the motor phase resistance, the power factor when the elevator car passes through the elevator equilibrium position, the line voltage effective value, and the line current effective value includes:

[0214] The downward mechanical power of the elevator car is calculated based on the motor phase resistance, the power factor when the elevator car passes through the elevator equilibrium position, the line voltage effective value, and the line current effective value:

[0215]

[0216] Among them, Ux is the motor running line voltage, Ix is the motor running line current, is the down-running power factor, Nx is the down-running mechanical power of the elevator car, Ef is the elevator transmission efficiency, and Rs is the motor phase resistance;

[0217] The upward mechanical power of the elevator car is calculated based on the motor phase resistance, the power factor when the elevator car passes through the elevator equilibrium position, the line voltage effective value, and the line current effective value:

[0218]

[0219] Among them, Us is the line voltage on the motor, Is is the line current on the motor, is the operating power factor, Ns is the upward mechanical power of the elevator car, Ef is the elevator transmission efficiency, and Rs is the motor phase resistance.

[0220] The elevator balance coefficient is calculated based on the upward mechanical power of the elevator car and the elevator car running speed when the elevator car passes through the elevator equilibrium position, including:

[0221] The calculation formula of the elevator balance coefficient is:

[0222] q=(Ns*Vx+Nx*Vs) / (2*Vs*Vx*gn*Q);

[0223] Among them, q is the elevator balance coefficient, Ns is the upward mechanical power of the elevator car, Nx is the downward mechanical power of the elevator car, Q is the rated load of the elevator, gn is the gravitational acceleration constant, Vs is the elevator speed when the elevator car passes the elevator equilibrium position, and Vx is the elevator speed when the elevator car passes the elevator equilibrium position.

[0224] The method further includes: displaying elevator operating status parameters, wherein the elevator operating status parameters include: elevator car operating speed, power factor, motor phase resistance, elevator car upward mechanical power, elevator car downward mechanical power, and elevator balance coefficient.

[0225] It should be noted that the elevator detection system also includes a display module for displaying elevator operating status parameters, including: elevator car operating speed, power factor, motor phase resistance, elevator car upward mechanical power, elevator car downward mechanical power, and elevator balance coefficient. In other words, the elevator detection system can display relevant power supply operating status parameters in real time, thereby providing real-time information on the calculation status of the entire elevator balance coefficient.

[0226] The present invention collects the three-phase voltage values ​​of a three-phase motor and the current values ​​of two of the three-phase currents. Based on the voltage composite vector in the two-phase αβ coordinates, the voltage phase angle, line voltage RMS, current phase angle, and line current RMS are obtained. The data from these composite vectors can be used in conjunction with the elevator balance coefficient to calculate the required real-time elevator car speed and distance. The elevator car distance can be used to accurately identify the moment when the elevator car passes through the elevator equilibrium position. The elevator balance coefficient is then calculated based on the elevator car speed, power factor, line voltage RMS, and line current RMS when the elevator car passes through the elevator equilibrium position. These calculations are performed based on the voltage and current values ​​of the three-phase motor. The entire calculation method can be performed in the elevator's no-load operating mode, avoiding many human factors and eliminating the need for multiple load adjustments by testers. The entire calculation process calculates elevator operating data at the over-balanced position based on the real-time collected voltage and current values, making subsequent calculation of the elevator balance coefficient more accurate. The entire elevator balance coefficient calculation can be completed in real time during elevator operation, making the calculation of the entire elevator balance coefficient faster.

[0227] An embodiment of the present invention provides a computer-readable storage medium having a computer program stored thereon. When executed by a processor, the program implements the method for calculating the elevator balance coefficient according to any of the above-described embodiments. The computer-readable storage medium includes, but is not limited to, any type of disk (including floppy disks, hard disks, optical disks, CD-ROMs, and magneto-optical disks), ROM (Read-Only Memory), RAM (Random Access Memory), EPROM (Erasable Programmable Read-Only Memory), EEPROM (Electrically Erasable Programmable Read-Only Memory), flash memory, magnetic cards, or optical cards. In other words, a storage device includes any medium that can store or transmit information in a readable form by a device (e.g., a computer or mobile phone), and can be a read-only memory, a disk, or an optical disk.

[0228] An embodiment of the present invention further provides a computer application program that runs on a computer and is used to execute the method for calculating the elevator balance coefficient of any one of the above embodiments.

[0229] In addition, the above is a detailed introduction to a method for calculating the elevator balance coefficient and an elevator detection system provided in an embodiment of the present invention. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for general technical personnel in this field, according to the idea of ​​the present invention, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A method for calculating the balance coefficient of an elevator, characterized in that: The method comprises: Collecting three-phase voltage values ​​of a three-phase motor, and calculating a voltage phase angle value and a line voltage effective value under a voltage synthesis vector in two-phase αβ coordinates based on the three-phase voltage values; Collecting two-phase current values ​​of the three-phase current of the three-phase motor, and calculating the current phase angle value and the line current effective value under the current synthesis vector in the two-phase αβ coordinates based on the two-phase current values; Calculating the elevator car running speed and the elevator car running distance based on the voltage phase angle value; Calculating a power factor based on the voltage phase angle value and the current phase angle value; Identifying a moment when the elevator car passes through an elevator equilibrium position based on the car travel distance, and calculating an elevator balance coefficient based on an elevator car travel speed, a power factor, an effective value of a line voltage, and an effective value of a line current when the elevator car passes through the elevator equilibrium position; The elevator balance coefficient is calculated based on the elevator car running speed, power factor, line voltage effective value and line current effective value when the elevator car passes through the elevator balance position, including: Calculating a motor phase resistance based on the power factor, the line voltage effective value, and the line current effective value when the elevator car passes through the elevator equilibrium position; Calculating an upward mechanical power of the elevator car and a downward mechanical power of the elevator car based on the motor phase resistance, the power factor when the elevator car passes through the elevator equilibrium position, the line voltage effective value, and the line current effective value; Calculating an elevator balance coefficient based on the upward mechanical power of the elevator car, the downward mechanical power of the elevator car, and the elevator car running speed when the elevator car passes through the elevator balance position; The calculating of the motor phase resistance based on the power factor, the line voltage effective value, and the line current effective value when the elevator car passes through the elevator equilibrium position includes: Obtain the running data and the down running data of the elevator car when it passes the elevator equilibrium position, and the running data includes: the running line voltage of the motor , Running line current on the motor , operating power factor The running data include: the motor running line voltage , Motor running line current , low operating power factor ; Calculate the motor phase resistance based on the up-running data and down-running data ,in: is the motor phase resistance, is the elevator transmission efficiency.

2. The method for calculating the balance coefficient of an elevator according to claim 1, wherein: Calculating the elevator car running speed and the elevator car running distance based on the voltage phase angle value includes: Calculate the voltage phase angle increment value at time t based on the voltage phase angle value at time t and the voltage phase angle value of the previous sampling period at time t; Calculating the elevator car running speed at time t based on the rated frequency of the elevator motor, the rated speed of the elevator car, and the voltage phase angle increment value; The distance traveled by the elevator car is calculated based on the integral of the speed over time.

3. The method for calculating the balance coefficient of an elevator according to claim 2, wherein: The step of calculating the elevator car running speed at time t based on the rated frequency of the elevator motor, the rated speed of the elevator car, and the voltage phase angle increment value includes: Calculate the angular frequency at time t based on the voltage phase angle increment; The elevator car running speed Va(t) at time t is calculated based on the relationship between the voltage frequency and the angular frequency of the voltage vector, where: ； is the speed of the elevator at time t, is the rated speed of the elevator, is the rated frequency of the elevator, for The voltage phase angle increment at the moment, is the frequency of the voltage at time t, for The angular frequency of the voltage vector at time , , T is the sampling period, .

4. The method for calculating the balance coefficient of an elevator according to claim 3, wherein: The calculation of the elevator car travel distance based on the integral of speed over time includes: The elevator car travel distance Sa is calculated based on the integral of speed over time, where: ； in, is the elevator running distance.

5. The method for calculating the balance coefficient of an elevator according to claim 1, wherein: The calculating of the upward mechanical power of the elevator car and the downward mechanical power of the elevator car based on the motor phase resistance, the power factor when the elevator car passes through the elevator equilibrium position, the line voltage effective value, and the line current effective value includes: The downward mechanical power of the elevator car is calculated based on the motor phase resistance, the power factor when the elevator car passes through the elevator equilibrium position, the line voltage effective value, and the line current effective value: ； in, is the downward mechanical power of the elevator car; The upward mechanical power of the elevator car is calculated based on the motor phase resistance, the power factor when the elevator car passes through the elevator equilibrium position, the line voltage effective value, and the line current effective value: ； in, It is the upward mechanical power of the elevator car.

6. The method for calculating the balance coefficient of an elevator according to claim 5, wherein: The elevator balance coefficient is calculated based on the upward mechanical power of the elevator car, the downward mechanical power of the elevator car, and the elevator car running speed when the elevator car passes through the elevator balance position, including: The calculation formula of the elevator balance coefficient is: ； in, is the elevator balance coefficient, is the rated load of the elevator, is the gravitational acceleration constant, It is the running speed of the elevator car when it passes the elevator equilibrium position. It is the downward running speed of the elevator car when it passes the elevator equilibrium position.

7. The method for calculating the balance coefficient of an elevator according to any one of claims 1 to 6, characterized in that: The method further includes: displaying elevator operating status parameters, wherein the elevator operating status parameters include: elevator car operating speed, power factor, motor phase resistance, elevator car upward mechanical power, elevator car downward mechanical power, and elevator balance coefficient.

8. An elevator detection system, characterized in that: The elevator detection system is configured to execute the method according to any one of claims 1 to 7.

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