Elevator inverter and busbar capacitance detection method thereof, elevator system and storage medium

Abstract

The present application discloses an elevator inverter and a busbar capacitance detection method thereof, an elevator system and a storage medium, wherein the elevator inverter includes a rectifier circuit, an inverter circuit and an intermediate circuit arranged on the busbar between the rectifier circuit and the inverter circuit, wherein the intermediate circuit includes a busbar capacitor and a brake circuit, and the inverter circuit is used to connect a motor; characterized in that the busbar capacitance detection method includes the following steps: determining a first moment and a second moment in the charging process of the busbar capacitor, wherein the first moment and the second moment are different moments; determining the power generation of the motor between the first moment and the second moment; determining a parameter representing the energy value stored in the busbar capacitor between the first moment and the second moment; and determining the busbar capacitance capacity according to the power generation and the energy value parameter. The present application can detect the busbar capacitance at the elevator operation site, with high detection efficiency and low cost.

Description

Technical Field

[0001] The present application relates to the technical field of display devices, and in particular to an elevator inverter and a bus capacitance detection method thereof, an elevator system and a storage medium. Background Art

[0002] After decades of development, elevators in my country have become an indispensable part of people's lives and one of the important construction equipment indispensable in urbanization construction in modern society.

[0003] In the rectification and filtering link of elevator inverters, large-capacity aluminum electrolytic capacitors are used very frequently. After long-term use, electrolytic capacitors will age, and the electrostatic capacitance and leakage current will change, which often causes a decline in product performance. Therefore, it is necessary to detect the capacitance and issue an early warning when an abnormality occurs, and then replace it during elevator maintenance to avoid elevator failure. However, it is difficult to directly measure the busbar capacitance at the elevator operation site, and most detection methods require the destruction of the existing system architecture (opening the inverter and using instruments for detection), and the manpower, time, and equipment costs of the detection are high. Summary of the invention

[0004] The main purpose of the present application is to provide an elevator inverter and a bus capacitance detection method thereof, an elevator system and a storage medium, aiming to solve the problem that the bus capacitance of the elevator inverter is difficult to detect when the elevator is running.

[0005] To achieve the above-mentioned object, the present application provides a bus capacitance detection method for an elevator inverter, wherein the elevator inverter comprises a rectifier circuit, an inverter circuit, and an intermediate circuit arranged on a DC bus between the rectifier circuit and the inverter circuit, wherein the intermediate circuit comprises a bus capacitance, and the inverter circuit is used to connect a motor; the bus capacitance detection method comprises the following steps:

[0006] Determine a first moment and a second moment in the charging process of the bus capacitor, wherein the first moment and the second moment are different moments;

[0007] determining the amount of power generated by the motor between the first moment and the second moment;

[0008] Determining a parameter representing an energy value stored in the bus capacitor between the first moment and the second moment;

[0009] The bus capacitance capacity is determined according to the power generation and the energy value parameter.

[0010] In one embodiment, the step of determining the power generation of the elevator inverter between the first moment and the second moment includes:

[0011] Obtaining an output current value of the inverter circuit, and determining an output voltage value of the inverter circuit;

[0012] A power generation integral value is calculated according to the output voltage value and the output current value, and the power generation integral value is used as the power generation of the inverter between the first moment and the second moment.

[0013] In one embodiment, the step of calculating the electric quantity integral value according to the output voltage value and the output current value comprises:

[0014] An integral value of the product of the output voltage value, the output current value and the inverter power factor from the first moment to the second moment is calculated, and the integral value is used as the power generation integral value.

[0015] In one embodiment, the step of determining the energy value parameter of the bus capacitor between the first moment and the second moment comprises:

[0016] Acquire a first voltage value of the DC bus at the first moment and a second voltage value of the DC bus at the second moment;

[0017] Acquire an energy difference algorithm having a relationship between the energy value and the bus capacitance;

[0018] The first voltage value, the second voltage value, the first moment and the second moment are input into the energy difference algorithm for calculation to obtain energy value parameters, wherein the energy value parameters include a conversion relationship between the energy value and the bus capacitance.

[0019] In one embodiment, the step of determining the bus capacitance according to the power generation and the energy value parameter comprises:

[0020] If the electric quantity value corresponding to the power generation is equal to the energy value parameter, the electric quantity value corresponding to the power generation is converted into the bus capacitance capacity according to the conversion relationship in the energy value parameter.

[0021] In one embodiment, the elevator inverter further includes an auxiliary power supply circuit, the auxiliary power supply circuit is connected to a bus, and the step of determining the bus capacitance according to the power generation and the energy parameter formula includes:

[0022] Determining the energy loss of the inverter circuit and the power consumption of the auxiliary power circuit;

[0023] If the electric quantity value corresponding to the power generation is equal to the sum of the energy loss, the power consumption of the power source and the energy value parameter, then the difference between the electric quantity value and the energy loss and the power consumption of the power source is determined to obtain the actual charging value of the bus capacitor;

[0024] The actual charging value is converted into the bus capacitance capacity according to the conversion relationship in the energy value parameter.

[0025] In one embodiment, the intermediate circuit further includes a braking circuit, the first moment is the moment when the bus capacitor starts to charge, and the second moment is the moment when the braking circuit is about to act.

[0026] To achieve the above-mentioned purpose, the present invention also provides an elevator inverter, the elevator inverter comprises a rectifier circuit, an inverter circuit, an intermediate circuit, at least one processor, and a storage device, the intermediate circuit is arranged between the rectifier circuit and the inverter circuit, and the intermediate circuit comprises a bus capacitor and a braking circuit; wherein a bus capacitor detection program of the elevator inverter is stored on the storage device, and when the bus capacitor detection program of the elevator inverter is executed by the processor, the steps of the bus capacitor detection method of the elevator inverter as described above are implemented.

[0027] To achieve the above object, the present invention further provides an elevator system, the elevator system comprising an elevator inverter, and the elevator inverter is configured as the elevator inverter described above.

[0028] To achieve the above objectives, the present invention also provides a computer-readable storage medium storing a bus capacitance detection program for an elevator inverter, and when the bus capacitance detection program for the elevator inverter is executed by a processor, the steps of the bus capacitance detection method for the elevator inverter as described above are implemented.

[0029] The elevator inverter and bus capacitance detection method thereof, elevator system and storage medium provided by the present application, the elevator inverter includes a rectifier circuit, an inverter circuit and an intermediate circuit arranged on the bus between the rectifier circuit and the inverter circuit, the intermediate circuit includes a bus capacitor and a brake circuit, and the inverter circuit is used to connect the motor; the bus capacitance detection method includes the following steps: determining the first moment and the second moment in the bus capacitance charging process, the first moment and the second moment are different moments; determining the power generation of the motor between the first moment and the second moment; determining the energy value parameter representing the energy value stored in the bus capacitance between the first moment and the second moment; determining the bus capacitance capacity according to the power generation and energy value parameters. Thus, the detection of the bus capacitance capacity is realized without destroying the existing system architecture, and the detection can also be realized when the elevator is running, with high detection efficiency and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic diagram of a partial hardware structure of an elevator inverter involved in an embodiment of the present application;

[0031] Figure 2 This is a flow chart of an embodiment of a busbar capacitance detection method for an elevator inverter of the present application;

[0032] Figure 3 This is another schematic diagram of the hardware structure of the elevator inverter involved in the embodiment of the present application;

[0033] Figure 4 This is a schematic diagram of the brake pipe drive and bus voltage waveforms in the braking state of the elevator inverter involved in the embodiment of the present application;

[0034] Figure 5 This is another schematic diagram of the brake pipe drive and bus voltage waveforms in the braking state of the elevator inverter involved in an embodiment of the present application.

[0035] The realization of the purpose, functional features and advantages of this application will be further described in conjunction with the embodiments and with reference to the accompanying drawings.

[0036] Label name Label name 100 Rectification circuit Cbus Bus Capacitor 200 Inverter circuit Rb Braking resistor 300 Intermediate circuit U1 Brake pipe 31 Braking circuit D1 diode 32 Soft start circuit M Motor DETAILED DESCRIPTION

[0037] It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application.

[0038] The main solution of the embodiment of the present application is: determine the first moment and the second moment in the charging process of the bus capacitor, the first moment and the second moment being different moments; determine the power generation of the motor between the first moment and the second moment; determine a parameter representing the energy value stored in the bus capacitor between the first moment and the second moment; determine the capacity of the bus capacitor according to the power generation and the energy value parameter.

[0039] Since the elevator frequency converter includes a rectifier circuit, an inverter circuit, and an intermediate circuit arranged on the bus between the rectifier circuit and the inverter circuit, the intermediate circuit includes a bus capacitor and a brake circuit, and the inverter circuit is used to connect the motor. The bus capacitor capacity is determined according to the motor power generation between the first moment and the second moment during the bus capacitor charging process and the energy value stored in the bus capacitor, so that the bus capacitor can also be detected at the elevator operation site without destroying the existing system architecture, with high detection efficiency and low cost.

[0040] As an implementation solution, the elevator inverter can be Figure 1 shown.

[0041] The embodiment of the present application relates to an elevator inverter, a temperature-sensitive resistor is provided on the source integrated circuit of the elevator inverter, and the resistance value of the temperature-sensitive resistor changes with the change of temperature. The elevator inverter includes: a processor 1001, such as a CPU, a memory 1002, and a communication bus 1003. Among them, the communication bus 1003 is configured to realize the connection and communication between these components.

[0042] The memory 1002 may be a high-speed RAM memory or a stable memory (non-volatile memory), such as a disk memory. Figure 1 As shown, the memory 1003 as a computer storage medium may include a bus capacitance detection program for the elevator inverter; and the processor 1001 may be configured to call the bus capacitance detection program for the elevator inverter stored in the memory 1002, and perform the following operations:

[0043] Determine a first moment and a second moment in the charging process of the bus capacitor, wherein the first moment and the second moment are different moments;

[0044] determining the amount of power generated by the motor between the first moment and the second moment;

[0045] determining a value representing energy stored in the bus capacitor between the first moment and the second moment;

[0046] The busbar capacitance capacity is determined according to the power generation and the energy value.

[0047] Based on the above hardware architecture, an embodiment of the bus capacitance detection method of the elevator inverter of the present application is proposed.

[0048] Reference Figure 2 , Figure 2 This is an embodiment of the bus capacitance detection method of the elevator inverter of the present application, and the bus capacitance detection method of the elevator inverter includes the following steps:

[0049] Step S10, determining a first moment and a second moment in the process of charging the bus capacitor, wherein the first moment and the second moment are different moments;

[0050] Step S20, determining the power generation of the motor between the first moment and the second moment;

[0051] Step S30, determining a parameter representing the energy value stored in the bus capacitor between the first moment and the second moment;

[0052] Step S40: determining the bus capacitance according to the power generation and the energy value parameter.

[0053] In this application, the execution subject is the controller of the elevator inverter. It should be noted that the main circuit inside the elevator inverter also includes three main components: a rectifier circuit, an intermediate circuit, and an inverter circuit. The rectifier circuit generally directly converts the AC power of the power grid into DC power through a three-phase rectifier bridge. This voltage is also called the DC bus voltage. The inverter circuit is an important part of the inverter. It is realized by high-frequency switching of the switching devices in the inverter circuit. The switching devices mostly use insulated gate bipolar transistors, and then the obtained high-frequency narrow pulses are used to impact the motor to obtain the required sine wave, and its voltage and frequency can be controlled to achieve stepless speed regulation. The intermediate circuit is between the rectifier circuit and the inverter circuit, which generally includes a filter circuit and a brake circuit. The filter circuit mainly includes a large-capacity aluminum electrolytic capacitor. This capacitor has the function of filtering and stabilizing voltage. Because the DC power obtained after rectification has a large ripple, it also needs to be filtered to provide a relatively stable DC power supply for the inverter circuit. When the host machine decelerates and brakes, the motor will become a generator, and the electric energy will return to the intermediate circuit through the inverter, so that the electric energy is stored in the large-capacity capacitor. When the forced braking feedback energy is too large and exceeds a certain value, the inverter will control the external braking resistor to consume the excess energy, thereby avoiding inverter overvoltage.

[0054] Reference Figure 3 In this embodiment, the elevator inverter includes a controller (not shown), a rectifier circuit 100, an inverter circuit 200, and an intermediate circuit 300 arranged between the rectifier circuit 100 and the inverter circuit 200. The intermediate circuit 300 includes a bus capacitor Cbus, a braking circuit 31, and a slow-start circuit 32. The bus capacitor Cbus is connected to the output end of the rectifier circuit 100, and the wires at both ends of the bus capacitor Cbus are the DC bus; the braking circuit 31 includes a brake tube U1, a diode D1, and a brake resistor Rbk; the slow-start circuit 32 includes a resistor R and a contact K at both ends of the resistor. An output current sampling circuit is also provided between the output end of the inverter and the motor M to obtain the inverter output current IO in real time, and a bus voltage sampling circuit is provided on the bus to obtain the two DC bus voltages Vbus in real time. When the inverter enters the braking mode, the motor M will become the generator's generated electric energy and store it in the bus capacitor Cbus through the inverter circuit 200. Refer to Figure 4 , when the bus capacitor Cbus starts to charge, the bus voltage gradually increases. Figure 4The figure is only an example. The actual original value of the bus voltage depends on the actual circuit structure, which is generally 540V. As the bus capacitor Cbus continues to charge, the bus voltage needs to start discharging when it reaches about 690V. Otherwise, the circuit will be damaged by excessive voltage. Therefore, when the bus voltage is high, the controller outputs the brake pipe drive voltage, turns on the brake pipe U1, and connects the brake resistor Rbk to the circuit. The electric energy in the bus capacitor Cbus can be released through the brake resistor Rbk to maintain the bus voltage at this time or reduce the bus voltage.

[0055] The first moment t1 and the second moment t2 can be any two moments in the entire bus capacitor Cbus charging process; the first moment t1 can be the previous moment of the second moment t2; this stage is the braking condition of the elevator inverter, that is, the power generation mode. In this stage, the inverter circuit 200 will convert the electric energy and store it in the bus capacitor Cbus. Therefore, by determining the power generation of the motor between the moments T1 and T2 and the energy value parameters stored in the bus capacitor (the bus capacitor Cbus in the energy value parameters can be represented by letters), the capacity of the bus capacitor Cbus at this time can be calculated.

[0056] The elevator inverter may also include an auxiliary power supply circuit, which is connected to the bus and charges the bus when the inverter is generating electricity. Therefore, an auxiliary power supply is made on the bus to power the drive module and sampling circuit, etc. The power of the auxiliary power supply can be set according to demand.

[0057] Since in the power generation mode, the power generation of the motor only charges the bus capacitor Cbus, the energy change of the capacitor Cbus can be used as the change of the output energy. Therefore, the bus capacitor capacity can be determined according to the power generation and the energy value parameter by making the power generation and the energy value parameter equal, so that the bus capacitor Cbus capacity can be obtained by calculation. If the calculation accuracy is required to be high, it is necessary to consider the power consumption of the auxiliary power supply circuit and the energy loss of the inverter circuit 200, determine the energy loss of the inverter circuit 200 and the power supply power of the auxiliary power supply circuit; at this time, it is necessary to make the power generation equal to the sum of the energy loss, the power supply power and the energy value parameter, and calculate the bus capacitor Cbus capacity. Therefore, it is judged whether the bus capacitor Cbus needs to be replaced based on the capacitance.

[0058] It should also be noted that the working condition of the elevator inverter also includes the electric mode, and the bus capacitance Cbus under this working condition can also be calculated according to this method. In the actual operation of the elevator inverter, the power generation mode and the electric mode work alternately, so it is only necessary to detect the capacity in one mode. And if the inverter used in other occasions has similar working conditions to the elevator inverter in this scheme, the bus capacitance detection method of the inverter in this scheme can also be used to continue the calculation.

[0059] In the technical solution provided in this embodiment, the elevator inverter includes a rectifier circuit 100, an inverter circuit 200 and an intermediate circuit 300 arranged on the bus between the rectifier circuit and the inverter circuit, the intermediate circuit 300 includes a bus capacitor Cbus and a braking circuit 31, and the inverter circuit 200 is used to connect the motor M; the bus capacitor detection method includes the following steps: determining the first moment t1 and the second moment t2 during the charging process of the bus capacitor Cbus, the first moment t1 and the second moment t2 are different moments; determining the power generation of the motor M between the first moment T1 and the second moment t2; determining the energy value parameter representing the bus capacitor Cbus stored between the first moment t1 and the second moment t2; determining the capacity of the bus capacitor Cbus according to the power generation and the energy value parameter, so that the bus capacitor Cbus can be detected at the elevator operation site without destroying the existing system architecture, and the detection efficiency is high and the cost is low.

[0060] In another embodiment of the bus capacitance detection method of the elevator inverter of the present application, the step S20 includes:

[0061] Step a, obtaining the output current value of the inverter circuit, and determining the output voltage value of the inverter circuit;

[0062] Step b: calculating an electric quantity integral value based on the output voltage value and the output current value, and using the electric quantity integral value as the power generation of the inverter between the first moment and the second moment.

[0063] In this embodiment, a current sampling circuit is provided at the output end of the inverter circuit 200, so that the current sampling circuit can feed back the output current value Io in real time, and the output voltage value Vo of the inverter circuit is calculated by the controller in real time according to the bus voltage, specifically the line voltage; thereby, the integral value of the motor power generation during the period from the first moment t1 to the second moment t2 can be obtained.

[0064] Specifically, the step of determining the power generation integral value according to the output voltage value and the output current value includes:

[0065] The integral value of the product of the output voltage value, the output current value and the inverter power factor from the first moment to the second moment is calculated, and the integral value is used as the power generation integral value. The following formula 1 can be referred to:

[0066]

[0067] Wherein, Vo represents the inverter output voltage, Io represents the inverter output current, t1 represents the first moment, t2 represents the second moment, and cosφ represents the power factor. The inverter output voltage Vo and the inverter output current Io are actually changing. In this embodiment, Vo and Io can be extracted in real time for integration.

[0068] In the technical solution provided in this embodiment, the power generation in a certain period of time can be calculated only by sampling the output current Io, and the bus capacitor capacity can be determined according to the power generation to determine whether the bus capacitor needs to be replaced, and the detection cost is low.

[0069] In another embodiment of the present application, step S30 includes:

[0070] Step c, obtaining a first voltage value of the DC bus at the first moment t1 and a second voltage value of the DC bus at the second moment t2;

[0071] Step d, obtaining an energy difference algorithm having a relationship between the energy value and the bus capacitance;

[0072] Step e: inputting the first voltage value, the second voltage value, the first moment and the second moment into the energy difference algorithm for calculation to obtain energy value parameters, wherein the energy value parameters include a conversion relationship between the energy value and the bus capacitance.

[0073] In this embodiment, a voltage sampling circuit is provided on the DC bus, so that when the first moment t1 and the second moment t2 are determined, the DC bus voltages V1 and V2 at the first moment t1 and the second moment t2 can be obtained. Specifically, the voltage sampling circuit can provide real-time feedback to the bus voltage value controller, and the controller can extract the first voltage value V1 and the second voltage value V2 at these two moments after determining the first moment t1 and the second moment t2. This method can obtain the voltage value of the bus at each moment, which is convenient for later calculation and analysis; or the controller can synchronously control the voltage sampling circuit to detect the bus voltage and provide feedback when determining the first moment t1 and the second moment t2. This method can reduce the power consumption of the voltage sampling circuit and reduce the storage space required for storing the bus voltage value.

[0074] The step of obtaining the energy difference algorithm having the relationship between the energy value and the bus capacitance comprises: obtaining a first product between the bus capacitance and the square of the first voltage value, and a second product between the bus capacitance and the square of the second voltage value; and subtracting the second product from the first product to obtain the energy difference algorithm. Referring to the following formula 2,

[0075]

[0076] Wherein, P2 represents the energy value, the Cbus represents the bus capacitance capacity to be determined, V1 represents the first voltage value, and V2 represents the second voltage value. Formula 2 after substituting V1 and V2 is the energy value parameter, which includes letters representing the energy value and the bus capacitance capacity. Therefore, the energy difference stored in the bus capacitance at the second moment t2 and the first moment t1 can be represented by the bus capacitance capacity to be determined, that is, the energy value stored on the bus capacitance during the power generation process. Further, Formula 2 is combined with Formula 1 to obtain the value of the bus capacitance Cbus. The first method is to make the electrical quantity corresponding to the power generation equal to the energy value parameter, that is, P1=P2. Then, according to the conversion relationship in the energy value parameter, the electrical quantity corresponding to the power generation is substituted, and the value of the bus capacitance Cbus to be calculated; or the electrical quantity corresponding to the power generation is equal to the sum of the energy loss, the power consumption and the energy value parameter, and the difference between the electrical quantity and the energy loss and the power consumption is determined to obtain the actual charging value of the bus capacitance; that is, P1 is equal to the sum of P2 and the power consumption of the auxiliary power circuit and the energy loss of the inverter circuit, and a more accurate value of the bus capacitance Cbus to be calculated.

[0077] In the technical solution provided in this embodiment, the bus voltage is sampled by a voltage sampling circuit, and the energy value stored on the bus capacitor during the time period is expressed by using the bus capacitor to be calculated. The bus capacitor capacity Cbus can be calculated in combination with the power generation. The algorithm is simple and fast, and can timely feedback the bus capacitor Cbus capacity, thereby improving the safety of the elevator.

[0078] Reference Figure 5 In another embodiment of the present application, the step S10 includes: the first moment t1 is the moment when the bus capacitor Cbus starts to charge, and the second moment t2 is the moment when the braking circuit 31 is about to act.

[0079] The moment when the bus capacitor Cbus starts to charge and the moment when the braking circuit 31 is about to act can be set according to actual conditions. For example, it can be judged based on the sampled bus voltage value. When the bus voltage starts to rise, it is judged that the bus capacitor starts to charge, and this moment is taken as the first moment t1. It can also be judged according to the current direction of the output current IO, and the moment when the current direction changes is taken as the moment when the bus capacitor starts to charge.

[0080] The specific action of the brake circuit 31 is that when the bus voltage reaches a "certain value", in order to protect the circuit from being damaged by overvoltage, the brake tube U1 in the brake circuit 31 is opened, and discharge is performed through the brake resistor Rbk. The moment when the brake circuit 31 is about to act is the moment when the brake tube U1 is about to be opened. The "certain value" can be a preset bus overvoltage threshold, such as 690V. When the bus voltage reaches the overvoltage threshold, the brake tube U1 in the brake circuit 31 is opened, and the moment when the bus voltage reaches the overvoltage threshold is used as the moment when the brake circuit 31 is about to act; the "certain value" can also be a variable overvoltage threshold according to circuit changes, such as 690V at one moment and 680V at another moment. The controller needs to control the brake tube U1 to open according to the changed overvoltage threshold, and use this moment as the first moment.

[0081] In the technical solution provided in this embodiment, by setting the rising moment of the bus voltage as the first moment t1, and the braking point (the moment when the brake pipe U1 is about to open) as the second moment t2, both moments are more specifically identifiable and easier to judge and determine, which makes the algorithm simpler and more accurate; and, at this time, the parameters such as power generation, the first voltage value, and the second voltage value have large changes, which can also improve the calculation accuracy during the calculation, thereby improving the detection accuracy and improving the elevator safety.

[0082] The present application also provides an elevator inverter, which includes a rectifier circuit, an inverter circuit, an intermediate circuit, at least one processor, and a storage device, wherein the intermediate circuit is arranged between the rectifier circuit and the inverter circuit, and the intermediate circuit includes a bus capacitor and a braking circuit; wherein the storage device stores computer executable instructions that can be executed by the at least one processor, and when the computer executable instructions are executed by the at least one processor, a processor executes the following steps: determining a first moment and a second moment in the charging process of the bus capacitor, the first moment and the second moment being different moments; determining the power generation of the motor between the first moment and the second moment; determining an energy parameter formula representing the energy value stored in the bus capacitor between the first moment and the second moment; and determining the capacity of the bus capacitor according to the power generation and the energy parameter formula.

[0083] The present application also provides an elevator system, which includes an elevator inverter. The elevator inverter can be configured with reference to the above embodiments and will not be described in detail here.

[0084] The present application also provides a computer-readable storage medium, which stores computer-executable instructions that can be executed by the at least one processor. When the computer-executable instructions are executed by the at least one processor, a processor performs the following steps: determining a first moment and a second moment in the charging process of the bus capacitor, the first moment and the second moment being different moments; determining the power generation of the motor between the first moment and the second moment; determining an energy value representing the energy stored in the bus capacitor between the first moment and the second moment; and determining the capacity of the bus capacitor based on the power generation and the energy value.

[0085] The serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0086] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0087] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present application is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, and includes a number of instructions for a terminal device (which can be a mobile phone, computer, server, TV, or network device, etc.) to execute the methods described in each embodiment of the present application.

[0088] The above are only optional embodiments of the present application, and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A busbar capacitance detection method for an elevator inverter, characterized in that: The elevator inverter includes a rectifier circuit, an inverter circuit, and an intermediate circuit arranged on a DC bus between the rectifier circuit and the inverter circuit, the intermediate circuit includes a bus capacitor, and the inverter circuit is used to connect a motor; the bus capacitor detection method includes the following steps: Determine a first moment and a second moment in the charging process of the bus capacitor, wherein the first moment and the second moment are different moments; determining the amount of power generated by the motor between the first moment and the second moment; Determining a parameter of energy value stored in the bus capacitor between the first moment and the second moment; The busbar capacitance capacity is determined according to the power generation and the energy value parameters.

2. The bus capacitance detection method of an elevator inverter according to claim 1, characterized in that: The step of determining the power generation of the elevator inverter between the first moment and the second moment comprises: Obtaining an output current value of the inverter circuit, and determining an output voltage value of the inverter circuit; A power generation integral value is calculated according to the output voltage value and the output current value, and the power generation integral value is used as the power generation of the inverter between the first moment and the second moment.

3. The bus capacitance detection method of the elevator inverter according to claim 2, characterized in that: The step of calculating the electric quantity integral value according to the output voltage value and the output current value comprises: An integral value of the product of the output voltage value, the output current value and the inverter power factor from the first moment to the second moment is calculated, and the integral value is used as the power generation integral value.

4. The busbar capacitance detection method of an elevator inverter according to claim 1, characterized in that: The step of determining the energy value parameter of the bus capacitance between the first moment and the second moment comprises: Acquire a first voltage value of the DC bus at the first moment and a second voltage value of the DC bus at the second moment; Acquire an energy difference algorithm having a relationship between the energy value and the bus capacitance; The first voltage value, the second voltage value, the first moment and the second moment are input into the energy difference algorithm for calculation to obtain energy value parameters, wherein the energy value parameters include a conversion relationship between the energy value and the bus capacitance.

5. The bus capacitance detection method of an elevator inverter according to claim 4, characterized in that: The step of determining the bus capacitance according to the power generation and the energy value parameter comprises: If the electric quantity value corresponding to the power generation is equal to the energy value parameter, the electric quantity value corresponding to the power generation is converted into the bus capacitance capacity according to the conversion relationship in the energy value parameter.

6. The bus capacitance detection method of an elevator inverter according to claim 4, characterized in that: The elevator frequency converter further includes an auxiliary power supply circuit, which is connected to a bus. The step of determining the bus capacitance according to the power generation and the energy value parameter includes: Determining the energy loss of the inverter circuit and the power consumption of the auxiliary power circuit; If the electric quantity value corresponding to the power generation is equal to the sum of the energy loss, the power consumption of the power source and the energy value parameter, then the difference between the electric quantity value and the energy loss and the power consumption of the power source is determined to obtain the actual charging value of the bus capacitor; The actual charging value is converted into the bus capacitance capacity according to the conversion relationship in the energy value parameter.

7. The bus capacitance detection method of an elevator inverter according to claim 1, characterized in that: The intermediate circuit also includes a braking circuit. The first moment is the moment when the bus capacitor starts to charge, and the second moment is the moment when the braking circuit is about to act.

8. An elevator frequency converter, characterized in that: The elevator inverter includes a rectifier circuit, an inverter circuit, an intermediate circuit, at least one processor, and a storage device, wherein the intermediate circuit is arranged between the rectifier circuit and the inverter circuit, and the intermediate circuit includes a bus capacitor and a braking circuit; wherein a bus capacitor detection program of the elevator inverter is stored on the storage device, and when the bus capacitor detection program of the elevator inverter is executed by the processor, the steps of the bus capacitor detection method of the elevator inverter as described in any one of claims 1 to 7 are implemented.

9. An elevator system, characterized in that: The elevator system includes an elevator inverter, and the elevator inverter is configured as the elevator inverter according to claim 8.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a bus capacitance detection program for an elevator inverter, and when the bus capacitance detection program for an elevator inverter is executed by a processor, the steps of the bus capacitance detection method for an elevator inverter according to any one of claims 1 to 7 are implemented.

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