Battery-based push-pull elevator energy recovery system

Abstract

The application discloses a battery-based push-pull type elevator energy recovery system, which comprises a DSP digital processing unit and an energy storage unit matched with the DSP digital processing unit, and further comprises a push-pull type step-up and step-down conversion circuit matched with the DSP digital processing unit to switch the energy storage unit to charge and discharge; wherein the energy storage unit is configured to adopt a battery module obtained by connecting lithium iron phosphate batteries or lithium titanate batteries in series or in series-parallel connection; the push-pull type step-up and step-down conversion circuit is configured to comprise full-bridge IGBT or MOS tubes and push-pull inductors matched with the full-bridge IGBT or MOS tubes. The battery-based push-pull type elevator energy recovery system provided by the application adopts the push-pull type step-up and step-down conversion circuit, which can ensure that a magnetic core works in a bidirectional magnetization mode, so that the conversion efficiency of the application is higher, the utilization rate of the magnetic core is higher, and the volume under the same power can be lower.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of elevator energy recovery, in particular to an elevator energy recovery device based on a battery, and more particularly to an energy-saving power supply method for secondary utilization of elevator energy. BACKGROUND

[0002] In all current elevator energy systems, the electromagnetic conversion of the power conversion circuit adopts a power inductor. The advantage of this power topology is that the high-low voltage ratio can be made very large. However, its defects are also very obvious, that is, in the same material, same process, and same volume capacity, because the inductor works in a unidirectional magnetization mode, the magnetic core is in an unbalanced magnetization state, that is, the so-called magnetic bias phenomenon. This causes the IGBT and the inductor itself to generate a large amount of heat when operating at full power under a high voltage difference, thereby causing the system to have a large loss and a low power conversion efficiency.

[0003] The energy storage unit of all elevator energy recovery systems developed by current elevator manufacturers adopts a super capacitor, and is equipped with a high-power BUCK / BOOST power conversion circuit. However, this method cannot be widely used by users in actual applications, and the reasons are as follows: on the one hand, the price of the super capacitor is too high, the capacity is small, and the voltage changes greatly in the working area; on the other hand, the PWM maximum duty ratio of the BUCK / BOOST power conversion circuit is large, the power inductor works in a unidirectional excitation state, and the magnetic bias is serious. In view of the above characteristics, the existing super capacitor energy storage unit with a BUCK / BOOST power conversion circuit has the following disadvantages: high price, large loss, large size, low magnetic capacity utilization rate, and poor reliability.

[0004] Therefore, only by reducing the overall cost, improving the reliability, and improving the power conversion efficiency to the greatest extent, can the user obtain energy-saving economic benefits, and promote the popularization of the elevator energy recovery system in the industry. SUMMARY

[0005] An object of the present application is to solve at least the above problems and / or defects, and to provide at least the advantages to be described later.

[0006] In order to achieve these objects and other advantages of the present application, a push-pull type elevator energy recovery system based on a battery is provided, which comprises a DSP digital processing unit and an energy storage unit cooperating with the DSP digital processing unit, and further comprises a push-pull type step-up / down conversion circuit cooperating with the DSP digital processing unit to switch the charge and discharge of the energy storage unit.

[0007] The energy storage unit is configured to adopt a battery module obtained by connecting a lithium iron phosphate battery or a lithium titanate battery in series or in series-parallel connection.

[0008] The push-pull type step-up / down conversion circuit is configured to include full-bridge IGBTs or MOS tubes and push-pull inductors matched therewith.

[0009] Preferably, the DSP digital processing unit is configured to adopt a digital analog signal hybrid processing circuit with TMS320F28035PAG as the core.

[0010] Preferably, the motor state detection unit matched with the DSP digital processing unit is further included.

[0011] The motor state detection unit is configured to include a bridge rectifier filter circuit and a power frequency current sensor or a Hall current sensor matched with the bridge rectifier filter circuit.

[0012] Preferably, in the push-pull type step-up / down conversion circuit, the full-bridge IGBTs are configured to adopt a full-bridge circuit composed of four IGBTs, and the midpoints of two half-bridges in the full-bridge circuit are respectively connected to two endpoints of the push-pull inductor.

[0013] The center tap of the push-pull inductor is connected to the energy storage unit.

[0014] Preferably, the working mode of the push-pull type step-up / down conversion circuit is configured to include:

[0015] When the elevator is in the power generation state, the voltage of the DC bus VBUS connected with the push-pull type step-up / down conversion circuit is raised, and then the Q3 and Q4 in the full-bridge circuit are kept open by the matched logic circuit and IGBT drive circuit, so as to serve as high-frequency rectifier diodes to rectify the passive winding of the push-pull inductor, and the center tap port of the push-pull inductor serves as a low-voltage DC output to continuously charge the battery energy storage unit.

[0016] The Q1 and Q2 in the full-bridge circuit are alternately turned on with the same duty ratio and 180-degree phase difference under the action of the logic circuit and IGBT drive circuit, so as to provide power input current for the push-pull inductor.

[0017] Preferably, the working mode of the push-pull type step-up / down conversion circuit is further configured to include:

[0018] When the elevator is in the power consumption mode, the first IGBT module Q1 and the second IGBT module Q2 are kept open under the action of the logic circuit IGBT drive circuit, so as to serve as high-frequency rectifier diodes to rectify the passive winding of the push-pull inductor, and the electrical energy stored in the energy storage unit is input through the center tap of the push-pull inductor, and the body diode of Q1 and Q2 provides a DC bus with a basic voltage equal to the battery energy storage unit.

[0019] The third IGBT module Q3 and the fourth IGBT module Q4 are turned on alternately with the same duty ratio and with a 180-degree phase difference under the action of the logic circuit and the IGBT driving circuit, so as to provide power input current for the push-pull inductor, and the collector output of Q1 and Q2 is a direct current voltage after being boosted by the push-pull inductor, and the voltage output to the direct current bus is kept at 500V-590V through the cooperation of the DSP digital processing unit and the voltage and current detection circuit.

[0020] Preferably, the application further comprises a direct current contactor arranged between the positive terminal of the direct current bus of the elevator controller and the push-pull step-up and step-down conversion circuit, so as to switch the connection and disconnection of the push-pull step-up and step-down conversion circuit.

[0021] Preferably, the application further comprises a three-phase alternating current power supply connected to the elevator controller through a matched elevator input switch.

[0022] Preferably, the application further comprises an isolated CAN communication module matched with the DSP digital processing unit, a non-isolated voltage detection module and a non-isolated current detection module.

[0023] Preferably, the isolated CAN communication module is configured to adopt one of an ISO1050 chip scheme or an optical coupling plus TJA1050 chip scheme.

[0024] The non-isolated voltage detection module is configured to detect the voltage of the direct current bus, the battery and the alternating current by means of resistance direct voltage division, and send the detected voltage value to the analog input port of the DSP digital processing unit, and then perform ADC conversion and digital signal processing in the DSP digital processing unit.

[0025] The non-isolated current detection module is configured to detect the charging and discharging current by means of sampling resistance, and send the detected current value to the analog input port of the DSP digital processing unit, and then perform ADC conversion and digital signal processing in the DSP digital processing unit.

[0026] The application has at least the following advantages: first, the main power circuit matched with the energy storage unit is a push-pull step-up and step-down conversion circuit, which adopts the combination of IGBT or MOS tube and push-pull inductor, and the working characteristics of the push-pull circuit can ensure that the magnetic core works in a bidirectional magnetization mode, so that the conversion efficiency of the application is higher, the utilization rate of the magnetic core is higher, and the volume is smaller under the same power.

[0027] Second, the application uses lithium iron phosphate battery or lithium titanate battery with voltage platform as the energy storage unit, and when the remaining capacity of the lithium iron phosphate battery or lithium titanate battery is close to 0, the voltage platform remains basically unchanged. Therefore, the application can utilize the full capacity space of the energy storage device without capacity cost waste problem.

[0028] Thirdly, the voltage boosting and voltage reducing of the application adopts double-tube push-pull mode, each switch tube is turned on in turn, and the maximum duty cycle is 50%, on the one hand, the switch tube will not appear long-term conduction, on the other hand, the push-pull transformer repeatedly works in self-induction voltage boosting and voltage reducing mode, the magnetic capacity utilization rate is high, the electromagnetic conversion efficiency is also high, and at the same time, due to the characteristics of the push-pull circuit, the highest voltage in the voltage boosting can be limited, that is, when the power circuit is out of control, the original elevator control system will not be damaged by the overhigh voltage.

[0029] Fourthly, the capacity utilization rate of the lithium iron phosphate battery or lithium titanate battery in the application can reach 100% on the full voltage platform, according to the current market price of supercapacitors and lithium iron phosphate batteries or lithium titanate, under the condition of meeting the same elevator system demand, the cost of the energy storage device required by the application is more than 50% lower than the cost of supercapacitors, so the system cost of the application is lower, which can bring more economic benefits to users, is easier for users to accept, and is more conducive to promoting the popularization of the elevator energy recovery system.

[0030] Other advantages, objects and features of the application will be embodied in part by the following description, and will be understood by those skilled in the art through research and practice of the application. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 The system composition block diagram of the push-pull type elevator energy recovery system based on the battery of the application is shown in the figure.

[0032] Figure 2 The schematic diagram of the push-pull type voltage boosting and voltage reducing conversion circuit of the application is shown in the figure.

[0033] Figure 3 The circuit structure schematic diagram of the LC transient matching module in the application is shown in the figure. DETAILED DESCRIPTION

[0034] The application will be further described in detail below with reference to the accompanying drawings, so that those skilled in the art can implement the application according to the description.

[0035] It should be understood that the terms such as "have", "contain" and "include" used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0036] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "provided with", "sleeved / connected", "connected" and the like should be understood in a broad sense, for example, "connected" can be fixedly connected, can be detachably connected, or integrally connected, can be mechanically connected, can be electrically connected, can be directly connected, can be indirectly connected through an intermediate medium, can be internal communication of two elements, and those skilled in the art can understand the specific meaning of the above terms in the present application according to the specific circumstances.

[0037] Figure 1 An implementation form of a battery-based push-pull elevator energy recovery system according to the present application is shown, which comprises a DSP digital processing unit (also referred to as a DSP hybrid control unit) 1 and an energy storage unit 2 cooperating therewith, and further comprises a push-pull boost-buck conversion circuit (also referred to as a push-pull power conversion circuit) 3 cooperating with the DSP digital processing unit to switch the energy storage unit for charging and discharging. In actual application, the DSP digital processing unit is configured to adopt a digital analog signal hybrid processing circuit with TMS320F28035PAG as the core, but is not limited to this type of DSP chip. The software is used to realize signal processing and various controls of each unit, and is a key device for control and signal processing of the whole system. It has the characteristics of built-in crystal oscillator, high reliability and low cost;

[0038] The energy storage unit is configured to adopt a lithium iron phosphate battery or a lithium titanate battery in series or in series-parallel to obtain a battery module. Its function is to store the generated power of the elevator in the generating state, and its capacity is configured according to the specific elevator power and total floor.

[0039] The push-pull boost-buck conversion circuit is configured to include full-bridge IGBT or MOS tube 30 and push-pull inductor 31 cooperating therewith to realize the functions of high-power boost and buck.

[0040] Further, in the push-pull boost-buck conversion circuit, the full-bridge IGBT is configured to adopt a full-bridge circuit composed of four IGBTs, and the midpoints of two half-bridges in the full-bridge circuit are respectively connected to the two endpoints of the push-pull inductor. The push-pull boost-buck conversion circuit is composed of four IGBTs and one push-pull inductor. When the elevator is in the generating state, the push-pull power conversion circuit converts the self-generated power of the elevator into the push-pull buck and charges the energy storage unit of the battery. When the elevator is in the power consumption state, the push-pull power conversion circuit converts the previously recovered power in the energy storage unit of the battery into the push-pull boost and provides it to the DC bus of the elevator.

[0041] The center tap of the push-pull inductor is connected to the energy storage unit.

[0042] The accompanying drawings Figure 2(Boost-buck power conversion principle diagram) The working mode of the boost-buck voltage conversion circuit of the application is described, and the core technology of the application is boost-buck power conversion. In order to facilitate understanding, a separate simplified circuit diagram is adopted for analysis. Figure 2 As can be seen from the attached Figure 2 The core idea of the boost-buck power conversion power supply is to use four IGBTs to form a full-bridge circuit, and the midpoints of the two half-bridges are connected to the two endpoints of the push-pull inductor. The center tap of the push-pull inductor is connected to the battery energy storage unit. In the application, the battery energy storage unit mainly adopts a multi-string series connection of lithium iron phosphate batteries or lithium titanate batteries.

[0043] Figure 2 VBUS is connected to the DC bus of the elevator controller, and VB is connected to the battery energy storage unit.

[0044] When the elevator is in power generation state, the DC bus voltage VBUS rises, the system keeps Q3 and Q4 open through the logic circuit and the IGBT drive circuit, uses the internal body diode as a high-frequency rectifier diode to realize the rectification of the passive winding of the push-pull inductor, and at the same time, the center tap port of the push-pull inductor is used as a low-voltage DC output to continuously charge the battery energy storage unit. In this process, the system makes Q1 and Q2 alternately conduct with the same duty ratio and 180-degree phase difference through the logic circuit and the IGBT drive circuit to provide power input current for the push-pull inductor.

[0045] When the elevator is in power consumption mode, the energy-saving system keeps Q1 and Q2 open through the logic circuit and the IGBT drive circuit, uses the internal body diode as a high-frequency rectifier diode to realize the rectification of the passive winding of the push-pull inductor, and the energy stored in the battery energy storage unit is input through the center tap of the push-pull inductor. Then, the body diode of Q1 and Q2 is used to provide a DC bus voltage equal to the basic voltage of the battery energy storage unit. At the same time, the system makes Q3 and Q4 alternately conduct with the same duty ratio and 180-degree phase difference through the logic circuit and the IGBT drive circuit to provide power input current for the push-pull inductor. At this time, the collector output of Q1 and Q2 is boosted through the push-pull inductor, and through the cooperation of the DSP control system and the voltage and current detection feedback network, the system adjusts the voltage output to the DC bus to be within 500V-590V (real-time adjustment according to the system detected three-phase mains voltage and motor power).

[0046] Further, the scheme further includes a motor state detection unit cooperating with the DSP digital processing unit.

[0047] The motor state detection unit is configured to include a bridge rectifier filter circuit and a power frequency current sensor or a Hall current sensor cooperating with the bridge rectifier filter circuit, in actual operation, when motor current is generated, the motor state detection system outputs a high level signal to inform the DSP system that the current motor is in operation, the motor state detection unit is also called a motor current detection circuit, which uses an alternating current electromagnetic transformer as a sampling device to sample the alternating current of the motor, and obtains a synchronous voltage signal through bridge rectification and integration circuit, and judges whether the motor is working through the signal.

[0048] Further, the scheme further includes: a DC contactor 20 arranged between the positive terminal of the DC bus of the elevator controller and the push-pull step-up / down conversion circuit, to switch the connection and disconnection of the push-pull step-up / down conversion circuit, and an isolated CAN communication module 21 cooperating with the DSP digital processing unit, a non-isolated voltage detection module (not shown), a non-isolated current detection module (not shown), a display module 22, and a system power supply (not shown);

[0049] Wherein, the external three-phase AC power is connected with the elevator controller 24 through the cooperating elevator input switch 23, in the scheme, the DC contactor is used to realize the connection and disconnection between the DC bus of the elevator controller and the main power circuit (i.e. the push-pull step-up / down conversion circuit) of the energy recovery system, when the external three-phase power is normally supplied, the DC contactor is driven to be closed after the system starts to work, so that the DC bus of the elevator controller is connected with the main power circuit of the energy recovery system, when the external three-phase power is off, the system stops driving the DC contactor, so that the DC bus of the elevator controller is disconnected with the main power circuit of the energy recovery system; the elevator input switch connects the three-phase AC power to the original elevator controller to supply power for the elevator control system, the elevator controller is mainly composed of elevator special frequency converters produced by different manufacturers to realize normal control of the elevator.

[0050] The isolated CAN communication module is configured to use one of an ISO1050 chip scheme or an optical coupling plus TJA1050 chip scheme, the function of the CAN communication module is to send various working parameters of the DSP digital processing unit to the outside of the device in an electrically isolated manner according to the CAN2.0 communication protocol, for the superior management device to read the working parameters of the energy-saving system;

[0051] The non-isolated voltage detection module is configured to detect the DC bus voltage, battery voltage and AC voltage in a resistance direct voltage division manner, and send the detected voltage values to the analog input port of the DSP digital processing unit, after ADC conversion in the DSP digital processing unit, digital signal processing is performed;

[0052] The non-isolated current detection module is configured to detect the charging and discharging current in the form of sampling resistance, and send the detected current value to the analog input port of the DSP digital processing unit, and after ADC conversion in the DSP digital processing unit, digital signal processing is carried out.

[0053] The display module is used for displaying various working parameters of the system in real time.

[0054] The system power supply adopts a flyback switching power supply with a wide input voltage range, high switching frequency and high conversion efficiency, and provides reliable and stable power supply for various functional circuits of the system, and the energy is derived from the storage battery; and the power supply of the system is derived from the energy storage unit composed of lithium iron phosphate battery or lithium titanate battery, which can reduce the system cost and ensure the reliable operation of the system.

[0055] Compared with the prior art, the present application has the following advantages:

[0056] 1. Since the existing elevator energy recovery system adopts super capacitor as the energy storage unit, there is no residual capacity for the elevator other function power supply. The present application adopts lithium iron phosphate battery or lithium titanate battery as the energy storage unit, which has a large capacity space and sufficient residual capacity for the elevator other function module power supply.

[0057] 2. The existing elevator energy recovery system adopts super capacitor as the energy storage device, and the capacity density of the super capacitor is low, so the relative cost is high under the same power level. The present application adopts lithium iron phosphate battery or lithium titanate battery with several times the capacity density of super capacitor, which can meet the life and large current characteristics and has lower unit price, so the capacity cost of the present application is lower under the same power level in terms of energy storage device selection.

[0058] 3. The existing elevator energy recovery system adopts the combination of inductance and IGBT in the boost and buck power conversion circuit, and the inductance works in the single excitation mode, which is not balanced in magnetization, and the utilization rate of the magnetic core is not high, and the conversion efficiency is not high, and the heat loss is large. The structure adopted by the present application is the combination of IGBT or MOS tube and push-pull inductance, and the working characteristics of the push-pull circuit can ensure that the magnetic core works in the bidirectional magnetization mode, so the conversion efficiency of the present application is higher, the utilization rate of the magnetic core is higher, and the volume is lower under the same power.

[0059] 4. Existing elevator energy recovery systems all use supercapacitors as energy storage devices. Since the capacity of a supercapacitor is directly proportional to its voltage, and only half of the supercapacitor's voltage range can be used in the entire system, half of the energy storage unit's cost is wasted, and this waste is unavoidable. This invention, however, uses lithium iron phosphate or lithium titanate batteries, which inherently possess a voltage platform, as energy storage units. When the remaining capacity of the lithium iron phosphate or lithium titanate battery approaches zero, its voltage platform remains essentially unchanged. Therefore, this invention can utilize the entire capacity space of the energy storage device, eliminating the problem of wasted capacity costs.

[0060] 5. Existing elevator energy recovery systems use a single-tube BUCK circuit for energy recovery and a single-tube BOOST circuit for secondary energy utilization. Because single-tube circuits have low efficiency and high heat loss, the switching transistors are prone to damage due to prolonged operation. This invention employs a dual-tube push-pull method for both boost and buck voltage, with each switching transistor conducting alternately at a maximum duty cycle of 50%. This prevents prolonged operation of the switching transistors and allows the push-pull transformer to repeatedly operate in a self-inductive boost / buck mode, resulting in high capacitance utilization and high electromagnetic conversion efficiency. Furthermore, the inherent characteristics of the push-pull circuit limit the maximum voltage during boost, preventing excessive voltage from damaging the existing elevator control system when the power circuit malfunctions.

[0061] 6. Existing elevator energy recovery systems use supercapacitors. Because the initial voltage of a supercapacitor is 0V, the energy recovery circuit is essentially short-circuited when the elevator is generating power. This results in a large current and very low recovery power, leading to low efficiency and most of the generated energy being converted into heat. In contrast, this invention uses lithium iron phosphate or lithium titanate batteries. Because lithium iron phosphate or lithium titanate batteries have a voltage plateau, the energy recovery circuit does not experience a short circuit when the elevator is generating power. Furthermore, the initial voltage plateau is relatively high, resulting in a larger minimum recovery power. Therefore, this invention offers higher energy recovery efficiency.

[0062] 7. Existing elevator energy recovery systems use supercapacitors with an initial voltage of 0V as energy storage devices. Each time the system starts, the energy storage unit must be charged to at least half its voltage level before the system can function properly, causing inconvenience for users. This invention, however, uses lithium iron phosphate or lithium titanate batteries, which inherently possess a voltage platform, as energy storage devices. Therefore, even if the remaining battery capacity is close to 0V, the voltage platform drop is minimal. Thus, this invention does not require pre-charging during system startup, making it more convenient to use.

[0063] 8. Existing elevator energy recovery systems suffer from low supercapacitor capacity density, resulting in a capacity utilization rate of only 50%. However, this invention, using lithium iron phosphate or lithium titanate batteries, achieves a 100% capacity utilization rate across the entire voltage platform. Considering the current market prices of supercapacitors and lithium iron phosphate or lithium titanate batteries, the cost of the energy storage devices required by this invention to meet the same elevator system requirements is more than 50% lower than that of supercapacitors. Therefore, the system cost of this invention is lower, bringing greater economic benefits to users, making it more acceptable to users, and promoting the widespread adoption of elevator energy recovery systems.

[0064] like Figure 3 In a further embodiment, an LC transient matching module is also included to increase the stability of the elevator energy recovery system. The LC transient matching module is configured to include:

[0065] The first LC filter circuit 4 is installed between the DC bus of the elevator controller and the step-up / step-down circuit of the elevator energy recovery system;

[0066] A second LC filter circuit 5 is installed between the energy storage unit and the step-up / step-down voltage circuit of the elevator energy recovery system;

[0067] The first LC filter circuit and the second LC filter circuit are grounded through the bidirectional transient voltage suppressor P16.

[0068] P1 is configured to be electrically connected to the equipment housing. In this solution, connecting the system's energy storage unit and the elevator controller's DC bus via an LC transient matching module effectively suppresses the transient effects caused by voltage fluctuations on the elevator controller's DC bus during elevator startup and shutdown under different load conditions. This increases the operational stability of the internal analog circuitry of the elevator energy recovery system and eliminates interference between the system and its internal components.

[0069] Furthermore, the first LC filter circuit is configured to include:

[0070] The first relay J1 40 and the second relay J2 41 are electrically connected to the positive and negative terminals of the DC bus of the elevator controller.

[0071] The third relay J3 42 and the fourth relay J4 43 are electrically connected to the high side of the elevator energy recovery system step-up / step-down voltage circuit and the negative terminal of the elevator energy recovery system.

[0072] The first inductor T1 44 is set between J1 and J3;

[0073] The first capacitor C145 and the second capacitor C246 are respectively set on the input and output sides of T1 and electrically connected to J2 and J4;

[0074] Wherein, the positive terminal and the negative terminal of the DC bus of the elevator controller, the high side of the voltage conversion circuit of the elevator energy recovery system and the negative pole of the elevator energy recovery system are respectively grounded through the first interference suppression capacitor, and the first interference suppression capacitor is C5, C6, C7 and C12 shown in FIG. 5. Figure 1 The first interference suppression capacitor is grounded through P1 and the mounting screw, and cooperates with T1 to form a high-frequency pulse-to-ground ∏ type filter suppression circuit, and the suppression effect is bidirectional effective, and C1, C2 and T1 form a DC bus power type transient ∏ type filter suppression circuit, and the suppression effect is bidirectional effective.

[0075] Further, the second LC filter circuit is configured to include:

[0076] The fifth relay J5 50 and the sixth relay J6 51 electrically connected to the positive terminal and the negative terminal of the energy storage unit;

[0077] The seventh relay J7 52 and the eighth relay J8 53 electrically connected to the low side of the voltage conversion circuit of the elevator energy recovery system and the negative pole of the elevator energy recovery system;

[0078] The second inductor T2 54 is arranged between J5 and J7;

[0079] The third capacitor C3 55 and the fourth capacitor C456 are respectively arranged at the input and output sides of T2 and electrically connected to J6 and J8;

[0080] Wherein, the positive terminal and the negative terminal of the DC bus of the elevator controller, the high side of the voltage conversion circuit of the elevator energy recovery system and the negative pole of the elevator energy recovery system are respectively grounded through the second interference suppression capacitor, and the second interference suppression capacitor is C8, C9, C10 and C11 shown in FIG. 8. Figure 1 The second interference suppression capacitor is grounded through P1 and the mounting screw, and cooperates with T2 to form a high-frequency pulse-to-ground ∏ type filter suppression circuit, and the suppression effect is bidirectional effective, and C3, C4 and T2 form a energy storage power type transient ∏ type filter suppression circuit, and the suppression effect is bidirectional effective.

[0081] The J4 and J8 are configured to be connected to the negative pole at the common point of the negative pole of the elevator energy recovery system, which improves the negative pole line impedance matching of the whole system and provides the stability of the negative pole power supply.

[0082] In actual application, the C1, C2, C3 and C4 are configured to adopt 800V / 15uF high-voltage high-frequency non-pole capacitor.

[0083] The first interference suppression capacitor and the second interference suppression capacitor are configured to use high-voltage ceramic capacitors with 2KV / 4.7nF, and also contain a way of using high-voltage thin film capacitors in parallel;

[0084] The T1 and T2 are configured to use PQ5050 magnetic cores and skeletons, and are wound with multiple strands of enameled wire. Of course, the T1 and T2 can also be configured to use ring-shaped magnetic cores or other forms of magnetic cores and skeletons, and are wound with enameled wire.

[0085] The above scheme is only a description of a preferred example, but is not limited thereto. In the implementation of the present application, appropriate substitutions and / or modifications can be made according to user needs.

[0086] The number of devices and the scale of processing described herein are intended to simplify the description of the present application. Applications, modifications and variations of the present application that are obvious to those skilled in the art are apparent.

[0087] Although the embodiments of the present application have been disclosed as above, it is not limited to the applications and embodiments listed in the specification. It can be fully applied to various fields suitable for the present application. Additional modifications can be easily made by those skilled in the art. Therefore, the present application is not limited to specific details and examples shown and described herein, without departing from the general concept defined by the claims and their equivalent scope.

Claims

1. A battery-based push-pull elevator energy recovery system, comprising a DSP digital processing unit and an energy storage unit working in conjunction with it, characterized in that, It also includes a push-pull buck-boost converter circuit that works with the DSP digital processing unit to switch the energy storage unit between charging and discharging. The energy storage unit is configured as a battery module obtained by connecting lithium iron phosphate batteries or lithium titanate batteries in series or in parallel. The push-pull buck-boost converter circuit is configured to include a full-bridge IGBT or MOSFET and a push-pull inductor that works in conjunction with it. The operation mode of the push-pull buck-boost converter circuit is configured to include: When the elevator is in power generation mode, the DC bus VBUS voltage connected to the push-pull step-up / step-down converter circuit rises, and then through the corresponding logic circuit and IGBT drive circuit, Q3 and Q4 in the full bridge circuit are kept open so as to be used as high-frequency rectifier diodes to rectify the passive winding of the push-pull inductor. The center tap of the push-pull inductor serves as a low-voltage DC output to continuously charge the battery energy storage unit. In the full-bridge circuit, Q1 and Q2 are alternately turned on with the same duty cycle and a 180-degree phase difference under the action of the logic circuit and the IGBT drive circuit, providing power input current to the push-pull inductor. The operation mode of the push-pull buck-boost converter circuit is configured to further include: When the elevator is in power consumption mode, the first IGBT module Q1 and the second IGBT module Q2 are kept disconnected under the action of the logic circuit IGBT drive circuit, so as to rectify the passive winding of the push-pull inductor as a high-frequency rectifier diode. The electrical energy stored in the energy storage unit is input through the center tap of the push-pull inductor. Based on the body diodes of Q1 and Q2, the DC bus is provided with a base voltage equal to that of the battery energy storage unit. Under the action of the logic circuit and the IGBT drive circuit, the third IGBT module Q3 and the fourth IGBT module Q4 are alternately turned on with the same duty cycle and a 180-degree phase difference to provide power input current for the push-pull inductor. The collector output of Q1 and Q2 is boosted to DC voltage through the push-pull inductor. With the cooperation of the DSP digital processing unit and voltage and current detection circuit, the voltage output to the DC bus is adjusted to be maintained at 500V-590V.

2. The battery-based push-pull elevator energy recovery system as described in claim 1, characterized in that, The DSP digital processing unit is configured as a digital-analog signal mixing processing circuit with TMS320F28035PAG as its core.

3. The battery-based push-pull elevator energy recovery system as described in claim 1, characterized in that, Also includes: A motor status detection unit that works in conjunction with a DSP digital processing unit; The motor status detection unit is configured to include: a bridge rectifier filter circuit, and a power frequency current sensor or a Hall current sensor that cooperates with the bridge rectifier filter circuit.

4. The battery-based push-pull elevator energy recovery system as described in claim 1, characterized in that, In the push-pull buck-boost converter circuit, the full-bridge IGBT is configured as a full-bridge circuit consisting of four IGBTs, and the midpoints of the two half-bridges in the full-bridge circuit are respectively connected to the two ends of the push-pull inductor. The center tap of the push-pull inductor is connected to the energy storage unit.

5. The battery-based push-pull elevator energy recovery system as described in claim 1, characterized in that, Also includes: A DC contactor is installed between the positive terminal of the DC bus of the elevator controller and the push-pull step-up / step-down conversion circuit to switch the connection and disconnection of the push-pull step-up / step-down conversion circuit. The external three-phase AC mains power is connected to the elevator controller through a matching elevator input switch.

6. The battery-based push-pull elevator energy recovery system as described in claim 1, characterized in that, It also includes an isolated CAN communication module that works with the DSP digital processing unit, a non-isolated voltage detection module, and a non-isolated current detection module; Among them, the isolated CAN communication module is configured to use either the ISO1050 chip solution or the optocoupler plus TJA1050 chip solution; The non-isolated voltage detection module is configured to detect DC bus voltage, battery voltage, and AC voltage using a direct resistor voltage divider method. The non-isolated current detection module is configured to detect the charging and discharging current by sampling a resistor.

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