Method for testing the capacity of drive rescue batteries for transport systems

Abstract

The invention relates to a method for testing the capacity of a drive rescue battery. The method comprises the following steps: - disconnecting an LCL filter from an AC power supply; - using the inductors and capacitors of the LCL filter as a test load for testing the capacity of the drive rescue battery, each of the inductors and capacitors of the LCL filter being connected to a first phase or to a second phase, wherein the inductor of the LCL filter connected to the first phase and connected downstream of the capacitor of the LCL filter connected to the first phase to a rectifier circuit, the capacitors of the LCL filter connected to the first phase and to the second phase, and the inductor of the LCL filter connected to the second phase and connected downstream of the capacitor of the LCL filter connected to the second phase to the rectifier circuit form a series connection as a test load; and - determining at least one value of the voltage or of the current of the drive rescue battery generated by the test load.

Description

TECHNICAL FIELD

[0001] The present invention relates to a method, a software program and a test device for testing the capacity of a drive rescue battery for driving an electric motor of a transportation system in a rescue operation mode. BACKGROUND

[0002] When a power drop or power loss occurs, a transportation system, such as an elevator, escalator, moving sidewalk, etc., can unexpectedly stop for the safety of the passengers using the transportation system. The elevator can be stalled between floors in the elevator shaft until the power supply is restored to the nominal operating voltage range. In conventional systems, the passengers in the elevator can be stranded until a maintenance worker can release the brake for controlling the car to move up or down to allow the elevator to move to the nearest floor. To improve this situation, elevator systems have been introduced that employ an automatic rescue operation. These elevator systems include an electrical energy storage device, for example in the form of a drive rescue battery, that is controlled to provide electrical power after a power failure to move the elevator to the next floor to let the passengers exit the elevator. Thus, the integrated rescue feature of a new generation of drives for elevators enables the battery to be discharged to drive internal loads, such as to move a stranded elevator car up or down to the nearest floor.

[0003] However, many of the current automatic rescue operation systems are complex and costly to implement and can provide unreliable power to the elevator drive after a power failure. For example, the battery capacity can decrease over time and usage. It is extremely important to replace a new rescue battery before the given battery capacity, i.e. stored charge, is too small to complete a rescue operation and thus the rescue operation can fail.

[0004] Previous attempts to ensure sufficient capacity of a drive rescue battery relied on an external load resistor or brake resistor that can have been used as a load resistor. Power from the drive rescue battery can also be provided to the electric motor of the elevator, but this test operation requires the safety chain of the elevator to be turned off and permission from the elevator level controller to perform the test. SUMMARY

[0005] It is therefore an object of the present invention to provide a method for testing the capacity of a drive rescue battery and a test device for testing the capacity of a drive rescue battery such that the rescue battery is always ensured to have sufficient capacity for a rescue operation in a simple, reliable and energy efficient manner.

[0006] This object is solved by the method, the computer program product and the test device according to embodiments of the present disclosure.

[0007] According to the method for testing the capacity of a drive rescue battery for driving an electric motor of a transportation system in a rescue operating mode, wherein in a normal operating mode an AC device supplies a frequency converter for driving the electric motor via a low pass LCL filter on a first phase, a second phase and a third phase, wherein the frequency converter comprises a rectifier circuit for providing a DC supply voltage. The method comprises the following steps:

[0008] disconnecting the LCL filter from the AC supply;

[0009] using the inductors and capacitors of the LCL filter as test load for testing the capacity of the drive rescue battery, each of the inductors and capacitors of the LCL filter being connected to the first phase or the second phase, wherein the inductor of the LCL filter connected to the first phase and connected downstream of the capacitor of the LCL filter connected to the first phase to the rectifier circuit, the capacitors of the LCL filter connected to the first phase and the second phase, and the inductor of the LCL filter connected to the second phase and connected downstream of the capacitor of the LCL filter connected to the second phase to the rectifier circuit form a series connection as test load; and

[0010] determining at least one value of the voltage or the current of the drive rescue battery generated by the test load.

[0011] An LCL filter (LCL stands for Inductor L - Capacitor C - Inductor L) is used to reduce the high order harmonics caused by the switching frequency of the electronically switchable switching devices (for example in the form of Insulated Gate Bipolar Transistors (IGBT)) of the rectifier circuit. A T-type LCL filter is a low pass filter specifically designed to reduce the current harmonics absorbed by the power converter through the rectifier input stage (for example the rectifier circuit of the frequency converter). Primarily, the LCL filter is made of a parallel-series combination of reactors or inductors and capacitors suitable to reduce the total harmonic distortion of the current of the rectifier, in short THD(I). They are specifically designed to reduce the THD(I) to a value of about 8% to comply with the IEC-61000-3.4 and IEEE-519 standards. The LCL filter can be disconnected from the AC supply downstream of the EMI filter (EMI is an acronym for Electromagnetic Interference) connected to the AC device.

[0012] The rectifier circuit can be in the form of an active front end (AFE). In an active front end, instead of using diodes in the rectifier circuit to convert the input AC voltage to DC voltage, IGBTs are used to convert the input AC power to DC. Other electronically switchable switching devices other than IGBTs can also be used. The input current waveform can be monitored and shaped into a sinusoidal curve by the AFE, thereby reducing the total harmonic distortion (THD) to below 5 percent, where the THD is measured only for low order harmonics. The inventive method can thus be performed with the aid of an active front end and an LCL filter as a test load / power sink for testing that the drive rescue battery has sufficient capacity to complete a rescue operation.

[0013] In the following the first, second and third phase are defined as power phases of an AC installation power supply to provide power to a user to drive a transportation system, such as a hoisting motor of an elevator. The voltage, current and power of each phase is offset 120° from the voltage, current and power of another phase. Each phase is associated with a power trunk, for example in the form of any kind of power line or power path, for example a conductive layer attached to a substrate like a PCB (printed circuit board), which in turn is conducted from the AC installation through an LCL filter to the rectifier circuit, which is isolated from the power trunks associated with the other phases. Any kind of drive rescue battery suitable for performing a rescue operation in an emergency situation of a transportation system can be used.

[0014] The method is able to test the capacity of a drive rescue battery by using the main circuit of the drive of the transportation system without the need to use external or additional equipment.

[0015] By using the inductor and capacitor of the LCL filter connected to the first phase and the second phase in any way as a test load for driving the capacity of the rescue battery, the load resistor is no longer needed. Furthermore, the battery test can be done without intervention of a transport system controller, such as an elevator controller. The output inverter connected to the electric motor and / or the electric motor itself does not need to be used for driving the capacity of the rescue battery, as the test load is provided by a series connection formed by the inductor of the LCL filter connected to the first phase and to the rectifier circuit downstream of the capacitor of the LCL filter connected to the first phase, the capacitor of the LCL filter connected to the first phase and the second phase, and the inductor of the LCL filter connected to the second phase and to the rectifier circuit downstream of the capacitor of the LCL filter connected to the second phase. At any time when the transport system is not occupied, the driver of the transport system can perform the battery test. The capacity of the battery can be tested occasionally, for example every month. The controller of the transport system, for example the elevator controller, can be able to detect when there is the least traffic and schedule the test of the battery capacity to that time period. For example, the battery test can be performed once a month for about 10 minutes, for example in the evening or at the weekend or after working hours.

[0016] The method of testing the capacity of the battery can be performed on a fully charged battery. During the test, the battery can be discharged with a constant electric power of for example 200 W. The duration of the test can be dependent on the type of the transport system, for example 10 minutes for a specific type of elevator. During the test, the voltage of the battery can be measured, wherein the voltage can drop proportional to the state of the battery. Thus, a simple and reliable method is provided to have the rescue battery always with sufficient capacity for rescue operation. At the same time, the inventive method is energy efficient for not requiring a motor to be moved to represent the test load.

[0017] The method is preferably performed by the further steps of:

[0018] modulating the electronically switchable switching device of the rectifier circuit, the electronically switchable switching device of the rectifier circuit being connected to the first phase and the second phase to generate an AC voltage from a DC supply voltage provided by the drive rescue battery, for example by pulse width modulation (PWM), wherein the AC voltage is applied to the test load.

[0019] The electronically switchable switching device of the rectifier circuit can be an insulated gate bipolar transistor. The gate of the electronically switchable switching device can be modulated to generate an AC voltage from a DC supply voltage provided by the drive rescue battery.

[0020] In another embodiment, the modulating of the first phase and the second phase of the rectifier circuit comprises the steps of:

[0021] - The high-side electronically switchable device connected to the rectifier circuit of the first phase and the low-side electronically switchable device connected to the rectifier circuit of the second phase are operated to be closed, while other electronically switchable devices connected to the rectifier circuits of the first and second phases are operated to be open, and

[0022] - The high-side electronic switch connected to the rectifier circuit of the second phase and the low-side electronic switch connected to the rectifier circuit of the first phase are operated to be closed, while the other electronic switch connected to the rectifier circuits of the first and second phases are operated to be open.

[0023] These two steps may occur sequentially, with the second step performed before or after the first. An intermediate step is also possible, provided both steps are performed during the testing of the rescue battery's capacity. The first step causes current to flow from the high side of the DC supply voltage to its low side. The second step causes current to flow in the opposite direction to the first step, i.e., from the low side of the DC supply voltage to its high side.

[0024] The electronically switchable device connected to the rectifier circuits of the first and second phases is preferably modulated such that the fundamental frequency and voltage level of the AC voltage across the capacitors of the LCL filters connected to the first and second phases are controlled to provide a constant discharge power to the drive rescue battery as a reference value (e.g., 200W), wherein the discharge value is determined by measuring the voltage and current of the drive rescue battery for comparison with the reference value. The first and second phases of the LCL filters are modulated with AC voltage via the electronically switchable device of the modulating rectifier circuits, and the fundamental frequency and voltage level across the LCL filter capacitors are controlled to maintain a constant discharge power. A discharge power of approximately 230V and approximately 10A at a frequency of approximately 1000Hz can be provided across the LCL filter capacitors connected to the first and second phases.

[0025] Preferably, when the series connection is used as a test load to test the capacity of the drive rescue battery, the motor is stationary. Therefore, the motor does not run during battery capacity testing. This makes energy-saving testing of the battery possible.

[0026] In an advantageous embodiment of the invention, after disconnecting the LCL filter from the AC power supply and before using the inductors and capacitors of the LCL filter, each connected to the first or second phase, as a test load, the method of the invention further includes the following steps:

[0027] - Disconnect the inductor connected to the third phase of the LCL filter from the rest of the LCL filter. This inductor is connected downstream of the capacitor in the LCL filter to the third phase of the rectifier circuit, and the capacitor is connected upstream of the inductor to the third phase; and

[0028] - Connect one terminal of the drive rescue battery to the inductor of the LCL filter connected to the third phase, so that the inductor forms a boost converter storage choke in rescue operation mode.

[0029] When battery testing is requested, the driver main circuit, including the LCL filter and the inverter's rectifier circuit, is isolated from the AC power supply to enable the use of the LCL filter and rectifier circuit, for example, in the form of an active front end, for loading a drive rescue battery. The battery negative terminal can be connected to the low side of the DC power supply voltage, which can be marked as the DC link negative potential. The battery positive terminal can be connected to the inductor of the LCL filter connected to the third phase, which acts as a storage choke for the boost converter. The boost converter can be formed by: a low-side electronically switchable switch connected to the rectifier circuit of the third phase, acting as a switch; and a diode switched in parallel with the high-side electronically switchable switch connected to the rectifier circuit of the third phase, acting as a boost rectifier.

[0030] Therefore, preferably, the boost converter comprises: a low-side electronically switchable device connected to the rectifier circuit of the third phase, serving as the boost converter switch; a diode switched in parallel with the high-side electronically switchable device connected to the rectifier circuit of the third phase, serving as the boost rectifier; and a capacitor intermediate device of the inverter for leveling the DC power supply voltage, serving as the boost converter capacitor. The high-side and low-side electronically switchable devices of the rectifier circuit may be IGBTs.

[0031] As described above, preferably, the negative terminal of the drive rescue battery is connected to the negative potential of the DC link of the DC power supply voltage, and the positive terminal of the drive rescue battery is connected to the inductor of the LCL filter connected to the third phase. Alternatively, the positive terminal of the drive rescue battery may be connected to the positive potential of the DC link of the DC power supply voltage, and the negative terminal of the drive rescue battery may be connected to the inductor of the LCL filter connected to the third phase.

[0032] Particularly preferably, the local drive unit of the inverter and / or an external server initiate and / or perform a test of the capacity of the drive rescue battery and / or analyze the results of the test, such as at least one value of at least one of the following measurements: voltage, current, voltage drop over time (e.g., 10 minutes), and / or current drop over time, to determine the energy / charge level of the drive rescue battery for comparison with a desired energy / charge level indicated by a threshold or several different thresholds used to weigh different emergency situations for maintaining the drive rescue battery.

[0033] Therefore, the battery's condition can be determined locally (e.g., in an elevator system) and / or externally on a cloud server through its capacity testing. If the condition drops below a threshold, maintenance requirements can be indicated / notified to the maintenance unit, service unit, and / or maintenance personnel (e.g., in this field), allowing maintenance to be scheduled and performed accordingly. There may be multiple thresholds that weigh the urgency of maintaining the drive rescue battery. For example, a first threshold might trigger an information / alarm indicating that maintenance of the drive rescue battery is scheduled for the next maintenance appointment. A second threshold indicating a lower battery capacity, as shown by the first threshold, could indicate the need for immediate maintenance. A third threshold indicating a lower battery capacity, as shown by the second threshold, could indicate the need to shut down the transportation system in a controlled manner, such as by moving the elevator car to the next floor to allow passengers to exit the elevator until the battery is replaced.

[0034] Following capacity testing of the emergency rescue battery, measurements of voltage, current, voltage drop over time, and / or current drop over time can be sent to a cloud server for analysis. The battery's energy / charge level required to perform worst-case rescue operations for the transportation system (e.g., an elevator system) can be determined and / or stored in the cloud. Based on the received battery test voltage and / or current measurements, the cloud server can calculate the energy / charge level of the emergency rescue battery and compare it to the energy / charge level required for worst-case rescue operations. The cloud server promptly indicates maintenance / replacement needs for the battery before it becomes unable to perform the required worst-case rescue operations, for example, based on the aforementioned threshold levels. Furthermore, the analysis of the emergency rescue battery capacity test results can alternatively be performed on an external server (such as a cloud server) or shared locally within a battery management system that has the required energy / charge level of the battery to perform worst-case rescue operations for the transportation system (e.g., an elevator system) stored in its memory. The battery management system can then send maintenance requirement information to the cloud server, service units, and / or maintenance personnel.

[0035] Another aspect of the invention is a software program that implements the method according to the invention when executed on a computer. In the aforementioned software program, the computer is preferably a distributed computing system, wherein the components of the computing system are located / arranged / run on a cloud computing system. The software program can be presented as a computer program product or a data carrier carrying data representing the software program.

[0036] The present invention also relates to a testing apparatus for testing the capacity of a drive rescue battery configured to drive an electric motor of a transport system in rescue operation mode. The testing apparatus includes...

[0037] The drive rescue battery and measuring device are configured to measure the voltage, current, voltage decrease over time (e.g., 10 minutes), and / or current decrease over time of the drive rescue battery.

[0038] The first, second, and third phases of the AC unit are configured to supply power from the AC unit to the frequency converter via a low-pass LCL filter. The frequency converter is configured to drive the motor in normal operating mode.

[0039] LCL filter,

[0040] The inverter's rectifier circuit is configured to provide DC power supply voltage.

[0041] The first switching device is configured to disconnect the AC unit from the LCL filter.

[0042] A second switching device is configured to disconnect an inductor connected to an LCL filter of the third phase from the rest of the LCL filter, wherein the inductor is connected downstream of a capacitor in the LCL filter, the capacitor being connected upstream of the inductor to the third phase.

[0043] The inverter's local drive unit and / or external server are configured to initiate and / or perform a test of the drive rescue battery's capacity, wherein...

[0044] If the first and second switching devices are disconnected, the inductors and capacitors of the LCL filter form a test load for testing the capacity of the driving rescue battery. Each of the inductors and capacitors of the LCL filter is connected to the first and second phases, wherein the inductor of the LCL filter connected to the first phase and downstream of the capacitor of the LCL filter connected to the first phase is connected to the rectifier circuit, the capacitor of the LCL filter connected to the first and second phases, and the inductor of the LCL filter connected to the second phase and downstream of the capacitor of the LCL filter connected to the second phase are connected in series as the test load. The advantages described in the present invention regarding the method for testing the capacity of the driving rescue battery apply accordingly to the test apparatus of the present invention. Each of the first and second switching devices may include one or more switches controlled by a switch control unit. Thus, several phases can be switched by a single switching device (e.g., together and simultaneously).

[0045] In another embodiment of the test apparatus, the inductor connected to the LCL filter of the first phase is connected to a link that connects the low-side and high-side electronically switchable devices of the rectifier circuit connected to the first phase, and the inductor connected to the LCL filter of the second phase is connected to a link that connects the low-side and high-side electronically switchable devices of the rectifier circuit connected to the second phase. Each link can be associated with a power line, for example, in the form of any kind of power line or electrical path, such as being attached to a conductive layer of a substrate (such as a PCB).

[0046] Advantageously, the testing apparatus includes a third switching device configured to disconnect one terminal of the drive rescue battery upstream of an inductor connected to the LCL filter of the third phase. This third switching device, if the first and second switching devices are open and the third switching device is closed, forms a boost converter storage choke in rescue operation mode. In this way, the battery can directly or via one or more converters (e.g., AFEs) and the LCL filter to provide power / charging to the capacitor intermediate device (i.e., the DC link) of the inverter used for leveling the DC power supply voltage, either directly or via the rectifier circuit. As described above, several phases can be switched (e.g., together or simultaneously) via the third switching device for the first and second switching devices.

[0047] In a preferred embodiment, the inductor connected to the LCL filter of the third phase is connected to a link that connects the low-side electronically switchable switch and the high-side electronically switchable switch of the rectifier circuit connected to the third phase, such that the inductor forms a boost converter storage choke in the rescue operation mode. The boost converter can then be formed by: the low-side electronically switchable switch connected to the rectifier circuit of the third phase as a boost converter switch; a diode switched in parallel with the high-side electronically switchable switch connected to the rectifier circuit of the third phase as a boost rectifier; and a capacitor intermediate device of the inverter for leveling the DC power supply voltage as a boost converter capacitor.

[0048] Further embodiments of the method, software program, and testing apparatus of the present invention include:

[0049] A transportation system consisting of one of elevators, escalators, and moving walkways, and / or

[0050] The rectifier circuit is formed by an active front end (AFE), and / or

[0051] At least one high-side and low-side electronically switchable switching device connected to the rectifier circuits of the first, second, and third phases is formed of an insulated-gate bipolar transistor. Therefore, the transport system is advantageously selected from one of elevators, escalators, and moving walkways. It is also possible to select a transport system from one of cable cars, railway locomotives, railcars, roller coasters, conveyors, cranes, positioning units, and combined systems of individual units of several of the above. Particularly preferred is an elevator or escalator as the transport system. Most preferably, the transport system is an elevator. In addition to IGBTs, which are electronically switchable switching devices for the rectifier circuits, MOSFETs (metal-oxide-semiconductor field-effect transistors), SiC (silicon carbide) MOSFETs, or any other high-power semiconductor switching devices can also be used. Attached Figure Description

[0052] Other aspects, features, and advantages of the invention will become apparent from the following description of exemplary embodiments or in conjunction with the accompanying drawings.

[0053] Figure 1 This is an electrical diagram of the motor and braking drive section of an elevator system including a drive rescue battery and a battery charger, according to an exemplary embodiment of the present invention.

[0054] Figure 2 This is an electrical diagram of a test apparatus used to test the capacity of a drive rescue battery, shown as follows. Figure 1 Excerpt,

[0055] Figure 3 The present invention relates to an electric motor for driving an elevator system in rescue operation mode. Figure 2 A simplified electrical diagram of the test setup, and

[0056] Figure 4 This is a set of three timing diagrams within 1 ms according to another embodiment of the present invention, wherein the top diagram shows the pulse width modulation sequence of the gates of two IGBTs connected to the rectifier circuit of one phase, the middle diagram shows the pulse width modulation sequence of the gates of two other IGBTs connected to the rectifier circuit of another phase, and the bottom diagram shows the resulting AC voltage generated by the pulse width modulation sequence of the gates of the IGBTs on the two inductors and two capacitors of the LCL filter, which serves as the test load for driving the rescue battery. Detailed Implementation

[0057] Exemplary embodiments of the present invention will now be described in more detail.

[0058] Figure 1Electrical diagrams are shown for the motor and brake drive section of an elevator system, including a drive rescue battery 10 and a battery charger 11 for driving the rescue battery 10. In normal operating mode, the motor and brake drive section are supplied with AC power by an AC unit 2, which supplies power to a frequency converter 8 via a low-pass LCL filter 4 on the first phase P1, second phase P2, and third phase P3. The motor 9 is used to move the elevator car of the elevator system. Phases P1, P2, and P3 provide an AC voltage offset of approximately 120 degrees relative to ground G. As shown, an EMI filter can be inserted between the AC unit 2 and the LCL filter 4. The frequency converter 8 includes a rectifier circuit 5 for providing a DC power supply voltage, a capacitor intermediate device 6 for leveling the DC power supply voltage, and an output inverter 7 for generating AC power as needed to supply the motor 9 to control the movement of the elevator car of the elevator system. The rectifier circuit 5, in the form of an active front end, includes electronically switchable switching devices T1 to T6, each having a diode connected in parallel to it and used as a freewheeling diode, such as the diode of the IGBT in T6. The electronically switchable switching devices T1 to T6 are IGBTs, with IGBTs T1, T3, and T5 located on the low side LS (which can be labeled as the negative DC link potential) of the DC power supply voltage, and IGBTs T2, T4, and T6 located on the high side HS of the DC power supply voltage. IGBTs T1 and T2 are linked to each other and connected to the first phase P1, IGBTs T3 and T4 are linked to each other and connected to the second phase P2, and IGBTs T5 and T6 are linked to each other and connected to the third phase P3. A corresponding electronically switchable switching device, in the form of IGBTs T7 to T12, is established in the output inverter 7 to generate AC voltage for the motor 9.

[0059] The battery charger 11 is connected not only to the positive DC terminal of the drive rescue battery, but also to the high side HS and low side LS of the DC power supply voltage. Therefore, the battery charger can also provide DC voltage to the capacitor intermediate device 6 and the redundant mechanical brake controller, and thus to the brake of the mechanical brake controller and brake 12. Furthermore, the capacitor intermediate device 6 of the inverter 8 can be used to charge the battery charger 11 in a regenerative manner using the inverter 8. Figure 1 In the illustrated design, battery 10 is connected between the negative potential of the DC link and the third phase P3. Battery charger 11 includes a transformer for reducing the DC link voltage of capacitor intermediate device 6 (also referred to as the DC link) to be suitable for battery 10, and is connected between the positive potential of the DC link and the positive DC terminal of battery 10. Battery charger 11 may include one or more switches capable of controlling charging. Figure 1In this diagram, the switch is shown as a transistor on the bottom left side of the transformer. Furthermore, the battery 10 may include a switch capable of controlling battery power supply, and... Figure 1 The two transistors shown are adjacent to each other. The redundant mechanical (motor) brake controller is connected to the DC link via a transformer and provides independent power to the redundant lifting mechanical (motor) brake.

[0060] The test apparatus 1 for testing the capacity of a drive rescue battery 10 according to the present invention comprises: a drive rescue battery 10; a first phase P1, a second phase P2, and a third phase P3 of an AC device 2, configured to supply power from the AC device 2 to a frequency converter 8 via a low-pass LCL filter 4 for driving a motor 9 in normal operating mode; an LCL filter 4; a rectifier circuit 5 of the frequency converter 8; a first switching device including switches S1, S1', and S1" for disconnecting the AC device 2 from the LCL filter 4; and a second switching device including a switch S2 for disconnecting the inductor L2" of the LCL filter 4, which is connected upstream of the inductor L2" of the third phase P3, from the remainder of the LCL filter 4. The inductor L2" is connected downstream of a capacitor C3 of the LCL filter 4, which is connected to the third phase P3.

[0061] Switch S1 is configured to disconnect LCL filter 4 from AC device 2, which is downstream of EMI filter 3 and connected to the first phase P1. Switch S1' is configured to disconnect LCL filter 4 from AC device 2, which is downstream of EMI filter 3 and connected to the second phase P2. Switches S1 and S1' are controlled by switch control unit SC1. Switch S1" is configured to disconnect LCL filter 4 from AC device 2, which is downstream of EMI filter 3 and connected to the third phase P3. Switches S1" and S2 are controlled by switch control unit SC2. If the first switches S1, S1', S1'" and the second switch S2 are open, then the inductors L2, L2' and capacitors C1, C2 of the LCL filter 4 form a test load for testing the capacity of the drive rescue battery 10, wherein L2 and C1 are connected to the first phase P1 and L2' and C2 are connected to the second phase P2. The inductor L1 of the LCL filter 4 connected upstream of capacitor C1 to the first phase P1, and the inductor L1' of the LCL filter 4 connected upstream of capacitor C2 to the second phase P2, are not part of a closed circuit and therefore do not operate. In contrast to L1 and L1', the inductors L2 and L2' are connected via the series-connected capacitors C1 and C2 to a rectifier circuit connected to the first phase P1 and the second phase P2 to modulate the IGBT. The gates of T1 to T4 are used to provide AC voltage to form a test load for driving the rescue battery 10. For this purpose, an inductor L2 connected to the first phase P1 and downstream of the capacitor C1 of the LCL filter 4 connected to the first phase P1 and connected to the LCL filter 4 of the rectifier circuit 5, capacitors C1 and C2 connected to the LCL filter 4 of the first phase P1 and the second phase P2, and an inductor L2' connected to the second phase P2 and downstream of the capacitor C2 of the LCL filter 4 connected to the second phase P2 and connected to the LCL filter 4 of the rectifier circuit 5 are connected in series as a test load for the battery 10.

[0062] The third switch S3 is configured to disconnect the DC positive terminal of the drive rescue battery 10 from the inductor L2” of the LCL filter 4 of the third phase P3, which is connected upstream of inductor L2”. This is because if the first switches S1, S1', S1” and the second switch S2 are open and the third switch S3 is closed, the inductor L2” of the LCL filter 4 connected to the third phase P3 forms a boost converter storage choke in the rescue operation mode and in the method of the present invention for testing the capacity of the battery 10. Switch S3 is controlled by the switch control unit SC3. When switches S1” and S2 are open by the switch control unit SC2, the inductor L1” of the LCL filter 4 of the third phase P3, which is connected upstream of capacitor C3, and the capacitor C3 of the LCL filter 4 of the third phase P3, which is connected downstream of inductor L2”, are not part of a closed circuit and therefore do not operate. When the first switches S1, S1', S1” and the second switch S2 are open and the third switch S3 is closed, the boost converter is formed by the following:

[0063] The inductor L2” of the LCL filter 4 is connected to the third phase P3 to form the boost converter storage choke.

[0064] - The low-side IGBT T5 of rectifier circuit 5 is connected to the third phase P3 as a switch for the boost converter.

[0065] - Diode D6, connected in parallel with the high-side IGBT T6 of rectifier circuit 5, is switched and connected to the third phase P3 as a boost rectifier, and

[0066] - The capacitor intermediate device 6 of the inverter 8, in particular the series-connected capacitor, is used as a boost converter capacitor to level the DC power supply voltage.

[0067] As Figure 1 Excerpt Figure 2 This is an electrical diagram of the test apparatus 1 used to test the capacity of the drive rescue battery 10. During the capacity test of the drive rescue battery 10, the battery can be used in boost operation as shown. When testing the battery for its capacity, the EMI filter 3 (see...) is... Figure 1 Switches S1, S1', and S1" between AC power supply 2 and LCL filter 4 are opened to disconnect AC power supply 2 from the test circuit. The AC power supply 2 is connected to the third phase P3 and is within the boundary of LCL filter 4. Figure 1The switch S2 shown is open to disconnect the inductor L1” and capacitor C3 from the second inductor L2 of the LCL filter. Then, the switch S3 arranged between the LCL filter 4 and the battery 10 is closed to connect the battery 10 to the AFE forming the rectifier circuit 5. Now, the low-side IGBT T5 connected between the third phase P3 and the low side LS (also known as the DC link negative potential or DC negative terminal) of the DC power supply voltage, and the high-side parallel diode D6 connected between the third phase P3 and the high side HS (also known as the DC link positive potential or DC positive terminal) of the DC power supply voltage, together with the second inductor L2” of the LCL filter 4, serve as a boost converter to provide DC voltage to the capacitor intermediate device 6 (also known as the DC link). The first inductor L1” and capacitor C3 of phase P3 are neither used in the boost operation nor as a test load. The inductors L2, L2' and capacitors C1, C2 of the LCL filter 4 of phases P1 and P2 are not part of the boost operation but are used as test loads. The inductors L1, L1' and capacitors C1, C2 are connected in series in the chain: L2 of phase P1, C1 of phase P1, C2 of phase P2, and L2' of phase P2. The inductors L1 of phase P1, L1' of phase P2, and L1” of phase P3 are not used in the boost operation or as test loads to drive the rescue battery 10.

[0068] Figure 3 The electric motor 9 according to the present invention is used to drive the elevator system in rescue operation mode. Figure 2 A simplified electrical diagram of test device 1. Once the first switch S1, S1', S1'" and the second switch S2 are open, Figure 2 The electrical diagram can be simplified to Figure 3 The modulation of the gate G1 of IGBT T1 and the gate G2 of IGBT T2 (each of IGBT T1 and T2 is connected to the first phase P1), and the gate G3 of IGBT T3 and the gate G4 of IGBT T4 (each of IGBT T3 and T4 is connected to the second phase P2) provides an AC voltage to a test load consisting of a series connection of inductor L2, capacitor C1, capacitor C2, and inductor L2'. First, switches S1, S1', S1'', and S2 are opened. Then, switch S3 is closed to set battery 10 to boost operation mode. The gates G1 to G4 of IGBTs T1 to T4 can then be modulated to provide a test load of the AC voltage generated by applying the series connection of devices L2, C1, C2, and L2' to battery 10. According to the invention, the control unit of inverter 8 can be responsible for starting, executing, and analyzing the test without the intervention of the elevator controller.

[0069] Electric motor 9 (see) Figure 1The inductor L2" cannot be operated during the capacity test of the drive rescue battery 10. During this test, only two phases P1 and P2 can be modulated to provide a constant AC discharge power, and the third phase P3 can be used for the boost operation of battery 10. Inductor L2" is only necessary for the boost operation of battery 10 and is not necessary for the test load operation of the series connection of L2, C1, C2, and L2'. If battery 10 is connected to the DC link in some other way, such as when the positive terminal of the drive rescue battery can be connected to the positive potential of the DC link of the DC power supply voltage, and the negative terminal of the drive rescue battery can be connected to the inductor of the LCL filter connected to the third phase, inductor L2" may not participate in the closed circuit and therefore does not operate. Therefore, the method of the present invention for testing the capacity of battery 10 by using devices L2, C1, C2 and L2” of LCL filter 4 as the test load of battery 10 may not require the battery to operate in boost mode. In order to approximate the load when the motor 9 is running, it is preferable to modulate the gates G1 to G4 of IGBTs T1 to T4 so that an AC voltage is generated as the test voltage of battery 10.

[0070] Figure 4 This is a set of three timing diagrams within 1 ms according to another exemplary embodiment of the present invention, wherein the top diagram shows the pulse width modulation sequence of the gates G1, G2 of IGBTs T1, T2 connected to the rectifier circuit 5 of the first phase P1. The middle diagram shows the pulse width modulation sequence of the gates G3, G4 of IGBTs T3, T4 connected to the rectifier circuit 5 of the second phase P2. The bottom diagram shows the resulting AC voltage 42 on the two inductors L2, L2' and two capacitors C1, C2 of the LCL filter 4, which serves as the test load for driving the rescue battery 10, generated by the pulse width modulation sequence of the gates G1 to G4 of IGBTs T1 to T4. The value of each capacitor in C1, C2 is 10 μF, and the value of each inductor in L2, L2' is 830 μH (no load). Other values ​​are possible.

[0071] The horizontal time scale 40 is the same for all figures in the 1ms range from 0.099 to 0.1 seconds. The pulse width modulation of each gate in gates G1 and G2 of IGBTs T1 and T2 is shown in the figures above on a scale from zero to 1 as the voltage stroke 41 applied to the corresponding gate, according to... Figure 1 , Figure 2 and Figure 3In each diagram, IGBTs T1 and T2 are electronically switchable devices linked together and connected to the low-side and high-side of the first phase P1. When the voltage is zero, no voltage is applied to the corresponding gate, causing the IGBT to not conduct and resulting in a switch open. When the voltage is 1, the full voltage is applied to the gate, causing the IGBT to conduct from source to drain and resulting in a switch closed. The pulse width modulation of each gate of IGBTs T3 and T4 is again shown in the middle diagram as a stroke 41 ranging from zero to 1. IGBTs T3 and T4 are electronically switchable devices linked together and connected to the low-side and high-side of the second phase P2. The diagram below shows the generated AC voltage full-wave test load, which includes a positive half-wave from 0.099s to 0.09955s with a maximum value of 230V shown on scale 42, and a subsequent negative half-wave from 0.09955s to 0.1s with a negative maximum value of -230V.

[0072] After switches S1, S1', S1" and S2 are opened and then switch 3 is closed to begin the capacity test of battery 10, the DC voltage supplied by battery 10 is boosted and converted to the high-side HS and low-side LS (DC link positive and DC link negative potentials) of the DC power supply voltage. Pulse width modulation is applied to the gates G1 to G4 of IGBTs T1 to T4 to generate AC voltages across the series-connected inductor L2, capacitors C1 and C2, and inductor L2'. The resulting test load for battery 10 is, for example, 230V, 10A at 1000Hz. Time intervals 45, 45', 45", 45", 45"" indicate the high-side IGBT T2 connected to the first phase P11 and the low-side IGBT connected to the second phase P2. T3 is turned on to technically allow current to flow from the high side to the low side of the DC power supply voltage. IGBTs T1 and T4 are not turned on, so they have no effect on the current. During time intervals 45 to 45””, there is a positive voltage 46 in the range of approximately 200 to 230V supplied by battery 10. During time intervals 47, 47’, 47”, 47”’, 47””, it indicates that the low-side IGBT T1 connected to the first phase P1 and the high-side IGBT T4 connected to the second phase P11 are turned on to technically allow current to flow from the low side to the high side of the DC power supply voltage (i.e., in the opposite direction to the current flowing during time intervals 45 to 45””). When IGBTs T1 and T4 are turned on, IGBTs T2 and T3 are not turned on, so they have no effect on the current. During time intervals 47 to 47””, there is a negative voltage 48 in the range of approximately -200 to -230V supplied by battery 10. The operation of gates G1 to G4 includes according to Figure 4Other switching modes of IGBTs T1 to T4 include, for example, after a time interval when IGBTs T2 and T3 are closed and IGBTs T1 and T4 are opened at t = 0.0992s (see time interval 45"), and then before a time interval when IGBTs T2 and T3 are closed again and IGBTs T1 and T4 are opened at t = 0.09925s (see time interval 45"), and a time interval when IGBTs T2 and T4 are closed and IGBTs T1 and T3 are opened at t = 0.09923s.

[0073] A constant discharge power is maintained by controlling the 1000Hz fundamental frequency and 230V voltage level on capacitors C1 and C2 of the LCL filter using a P (proportional) or PI (proportional-integral) controller. A PID (proportional-integral-derivative) controller is also possible. First, a discharge power reference value is set, for example, to 200W. Then, the (actual) discharge power value is obtained using the battery's current and voltage measurements. This (actual) discharge power value is subtracted from the discharge power reference value to determine the controller's error value. Based on the determined error value, the fundamental frequency or voltage on capacitors C1 and C2 is increased, decreased, or kept constant until the next battery current and voltage measurement.

[0074] This invention provides a method for testing the capacity of a drive rescue battery, wherein during normal operation of a transportation system (e.g., an elevator system), a first switching device including first switches S1, S1', S1'' and a second switching device including a second switch S2 are closed, and a third switching device including a third switch S3 is open. When the battery capacity test is initiated, the first and second switching devices are open. Then the third switching device is closed. The battery voltage is boosted by an electronically switchable device T5 connected to the low side of the third phase P3 of the rectifier circuit 5 to power the capacitor intermediate device 6 of the inverter 8 to level the DC power supply. The electronically switchable devices T1 to T4 of the rectifier circuit 5, connected to the first phase P1 and the second phase P2, are modulated to provide AC voltage to the series connection of passive components of the LCL filter 4, which includes the inductor L2 connected to the first phase P1, the capacitor C1 connected to the first phase P1, the capacitor C2 connected to the second phase P2, and the inductor L2' connected to the second phase P2. Since the series connection forms a known impedance, and the power supplied to that impedance is known based on, for example, the modulation of the electronically switchable devices T1 to T4 of the rectifier circuit 5, the power discharged from the battery 10 can be determined.

[0075] One or more technical features disclosed in one or more embodiments discussed above (e.g., embodiments concerning the testing method or apparatus for the capacity of the drive rescue battery of an elevator system) may also appear in another embodiment, such as concerning an escalator or crane, unless it is specified that it / they do not exist or are impossible to appear for technical reasons.

Claims

1. A method for testing the capacity of a drive rescue battery (10) for driving an electric motor (9) of a transportation system in a rescue operating mode, wherein in a normal operating mode an AC power supply (2) supplies a frequency converter (8) via a low-pass LCL filter (4) on a first phase (PI), a second phase (P2) and a third phase (P3) for driving the electric motor (9), wherein the frequency converter (8) comprises a rectifier circuit (5) for providing a DC supply voltage, wherein the method comprises the following steps: disconnecting the LCL filter (4) from the AC power supply (2); using the inductors (L2, L2') and capacitors (CI, C2) of the LCL filter (4) connected to the first phase (PI) and the second phase (P2) as a test load for testing the capacity of the drive rescue battery (10), wherein the inductor (L2) of the LCL filter (4) connected to the first phase (PI) and connected downstream of the capacitor (CI) of the LCL filter (4) connected to the first phase (PI) to the rectifier circuit (5), the capacitors (CI, C2) of the LCL filter (4) connected to the first phase (PI) and the second phase (P2), and the inductor (L2') of the LCL filter (4) connected to the second phase (P2) and connected downstream of the capacitor (C2) of the LCL filter (4) connected to the second phase (P2) to the rectifier circuit (5) form a series connection as the test load; and determining at least one value of a voltage or a current of the drive rescue battery (10) generated by the test load.

2. The method according to claim 1, further comprising: modulating electronic switchable switching devices (T1-T4) of the rectifier circuit (5) connected to the first phase (PI) and the second phase (P2) by pulse width modulation (PWM) to generate an AC voltage from the DC supply voltage provided by the drive rescue battery (10) which is applied to the test load.

3. The method according to claim 2, wherein the modulation of the first phase (PI) and the second phase (P2) of the rectifier circuit (5) comprises the following steps: operating a high side (HS) electronic switchable switching device (T2) of the rectifier circuit (5) connected to the first phase (PI) and a low side (LS) electronic switchable switching device (T3) of the rectifier circuit (5) connected to the second phase (P2) to be closed while operating other electronic switchable switching devices (T1, T4) of the rectifier circuit (5) connected to the first phase (PI) and the second phase (P2) to be open, and - operating the high-side (HS) electronically switchable switching device (T4) of the rectifier circuit (5) connected to the second phase (P2) and the low-side (LS) electronically switchable switching device (T1) of the rectifier circuit (5) connected to the first phase (P1) as closed, while operating the other electronically switchable switching devices (T2, T3) of the rectifier circuit (5) connected to the first phase (P1) and to the second phase (P2) as open.

4. The method according to claim 2 or claim 3, wherein the electronically switchable switching devices (T1-T4) of the rectifier circuit (5) connected to the first phase (P1) and to the second phase (P2) are modulated so that the fundamental frequency and voltage level of the AC voltage on the capacitors (C1, C2) of the LCL filter (4) connected to the first phase (P1) and to the second phase (P2) are controlled to provide a constant discharge power to the drive jump-start battery (10) as a reference value, wherein by measuring the voltage and current of the drive jump-start battery (10), a discharge value is determined for comparison with the reference value.

5. The method according to claim 4, wherein the reference value is 200 W.

6. The method according to any one of claims 1 to 3, wherein the electric motor (9) is in a stationary state when the series connection is used as the test load for testing the capacity of the drive jump-start battery (10).

7. The method according to any one of claims 1 to 3, further comprising the following steps after disconnecting the LCL filter (4) from the AC power supply (2) and before using the inductors (L2, L2') and the capacitors (C1, C2) of the LCL filter (4) connected to the first phase (P1) and to the second phase (P2) as the test load: - disconnecting the inductor (L2'') of the LCL filter (4) connected to the third phase (P3) downstream of the capacitor (C3) of the LCL filter (4) connected to the third phase (P3) upstream of the inductor (L2''), from the rest of the LCL filter (4); and - connecting one terminal of the drive jump-start battery (10) to the inductor (L2'') of the LCL filter (4) connected to the third phase (P3) so that the inductor (L2'') forms a boost converter storage choke in the jump-start operating mode.

8. The method according to claim 7, wherein the boost converter is formed by a low side (LS) electronically switchable switching device (T5) of the rectifier circuit (5) connected to the third phase (P3) as boost converter switch, a diode (D6) switched in parallel to a high side (HS) electronically switchable switching device (T6) of the rectifier circuit (5) connected to the third phase (P3) as boost rectifier, and a capacitive intermediate device (6) of the frequency converter (8) for regulating the DC supply voltage as boost converter capacitor.

9. The method according to claim 7, wherein a negative terminal of the drive rescue battery (10) is connected to a DC link negative potential of the DC supply voltage and a positive terminal of the drive rescue battery (10) is connected to the inductor (L2”) of the LCL filter (4) connected to the third phase (P3), or the positive terminal of the drive rescue battery (10) is connected to a DC link positive potential of the DC supply voltage and the negative terminal of the drive rescue battery (10) is connected to the inductor (L2”) connected to the third phase (P3) of the LCL filter (4).

10. The method according to any one of claims 1 to 3, wherein a local drive unit of the frequency converter (8) and / or an external server initiates and / or performs the test of the capacity of the drive rescue battery (10) and / or analyzes the results of the test of the capacity of the drive rescue battery (10) to determine an energy / charge level of the drive rescue battery (10) for comparison with a required energy / charge level indicated by a threshold value or several threshold values different from each other for weighing different emergency situations for maintaining the drive rescue battery (10).

11. The method according to claim 10, wherein the results of the test comprise at least one value of at least one measurement of a voltage, a current, a voltage drop over time and / or a current drop over time of the drive rescue battery (10).

12. The method according to claim 11, wherein the voltage drop over time of the drive rescue battery (10) comprises a drop of the voltage of the drive rescue battery (10) within 10 minutes.

13. The method according to any one of claims 1 to 3, wherein the transportation system is formed by one of an elevator, an escalator and a moving sidewalk, and / or the rectifier circuit is formed by an active front end (AFE), and / or at least one high side (HS) electronically switchable switching device (T2, T4, T6) and at least one low side (LS) electronically switchable switching device (T1, T3, T5) of the rectifier circuit (5) connected to the first phase (P1), the second phase (P2) and the third phase (P3) are formed by insulated gate bipolar transistors (IGBT). ​ ​ ​ 14. A software program which, when executed on a computer, implements the method according to any one of the preceding claims, wherein the computer is a distributed computing system, a part of which is located in a cloud computing system.

15. A test device (1) for testing the capacity of a drive rescue battery (10) configured to drive an electric motor (9) of a transportation system in a rescue operating mode, wherein the test device (1) comprises: the drive rescue battery (10) and a measuring device configured to measure the voltage, the current, the voltage drop over time and / or the current drop over time of the drive rescue battery (10), a first phase (PI), a second phase (P2) and a third phase (P3) of an AC power source (2) configured to supply power from the AC power source (2) to a frequency converter (8) via a low-pass LCL filter (4), the frequency converter (8) being configured to drive the electric motor (9) in a normal operating mode, the LCL filter (4), a rectifier circuit (5) of the frequency converter (8) configured to provide a DC supply voltage, a first switching device (SI, SI', SI'') configured to disconnect the AC power source (2) from the LCL filter (4), a second switching device (S2) configured to disconnect an inductor (L2'') of the LCL filter (4) connected to the third phase (P3) from the rest of the LCL filter (4), wherein the inductor (L2'') is connected downstream of a capacitor (C3) of the LCL filter (4), the capacitor (C3) being connected to the third phase (P3) upstream of the inductor (L2''), and a local drive unit of the frequency converter (8) and / or an external server configured to initiate and / or perform the test of the capacity of the drive rescue battery (10), wherein If the first switching device (S1, S1', S1") and the second switching device (S2) are open, the inductor (L2, L2') and the capacitors (C1, C2) of the LCL filter (4) that are connected to the first phase (P1) or to the second phase (P2) form a test load for testing the capacity of the drive rescue battery (10), wherein the inductor (L2) of the LCL filter (4) that is connected to the first phase (P1) and that is connected downstream of the capacitor (C1) of the LCL filter (4) that is connected to the first phase (P1) to the rectifier circuit (5), the capacitors (C1, C2) of the LCL filter (4) that are connected to the first phase (P1) and to the second phase (P2), and the inductor (L2') of the LCL filter (4) that is connected to the second phase (P2) and that is connected downstream of the capacitor (C2) of the LCL filter (4) that is connected to the second phase (P2) to the rectifier circuit (5) form a series connection as the test load.

16. The test device (1) according to claim 15, wherein the drop of the voltage of the drive rescue battery (10) over time comprises a drop of the voltage of the drive rescue battery (10) within 10 minutes.

17. The test device (1) according to claim 15, wherein the inductor (L2) of the LCL filter (4) that is connected to the first phase (P1) is connected to a link that connects a low-side (LS) electronically switchable switching device (T1) and a high-side (HS) electronically switchable switching device (T2) of the rectifier circuit (5) that are connected to the first phase (P1), and the inductor (L2') of the LCL filter (4) that is connected to the second phase (P2) is connected to a link that connects a low-side (LS) electronically switchable switching device (T3) and a high-side (HS) electronically switchable switching device (T4) of the rectifier circuit (5) that are connected to the second phase (P2).

18. The test device (1) according to any one of claims 15 to 17, further comprising: a third switching device (S3) configured to disconnect one terminal of the drive rescue battery (10) upstream of the inductor (L2") of the LCL filter (4) that is connected to the third phase (P3), wherein, if the first switching device (S1, S1', S1") and the second switching device (S2) are open, and the third switching device (S3) is closed, the inductor (L2") of the LCL filter (4) that is connected to the third phase (P3) forms a boost converter storage choke in the rescue operation mode.

19. The test arrangement (1) according to claim 18, wherein the inductor (L2'') of the LCL filter (4) connected to the third phase (P3) is connected to a link connecting a low side (LS) electronically switchable switching device (T5) and a high side (HS) electronically switchable switching device (T6) of the rectifier circuit (5) connected to the third phase (P3).

20. The test arrangement according to any one of claims 15 to 17, wherein the transportation system is formed by one of an elevator, an escalator and a moving sidewalk, and / or the rectifier circuit is formed by an active front end (AFE), and / or at least one high side (HS) electronically switchable switching device (T2, T4, T6) and at least one low side (LS) electronically switchable switching device (T1, T3, T5) of the rectifier circuit (5) connected to the first phase (P1), the second phase (P2) and the third phase (P3) are formed by insulated gate bipolar transistors (IGBTs).

21. The test arrangement according to any one of claims 15 to 20, wherein the rectifier circuit (5) is formed by a plurality of insulated gate bipolar transistors (IGBTs) connected in series, and / or the rectifier circuit (5) is formed by a plurality of insulated gate bipolar transistors (IGBTs) connected in parallel, and / or the rectifier circuit (5) is formed by a plurality of insulated gate bipolar transistors (IGBTs) connected in series and in parallel.

22. The test arrangement according to any one of claims 15 to 21, wherein the rectifier circuit (5) is formed by a plurality of insulated gate bipolar transistors (IGBTs) connected in series and in parallel, and the rectifier circuit (5) is formed by a plurality of insulated gate bipolar transistors (IGBTs) connected in series and in parallel, and the rectifier circuit (5) is formed by a plurality of insulated gate bipolar transistors (IGBTs) connected in series and in parallel.

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