A decomposition battery type mining electric locomotive energy recovery device and control method

Abstract

The present invention discloses a decomposition battery type mining electric locomotive energy recovery device and control method, belonging to the technical field of energy-saving application of mining equipment, comprising a battery pack 1 and a battery pack 2, characterized in that according to the actual application occasions of the mining electric locomotive and the uphill and downhill states of the electric locomotive, a controller controls the frequency converter to switch the electric state or the power generation state of the drive motor through a communication line, and at the same time, the controller reads the BMS remaining power information (SOC) of the battery pack 2 through the CAN bus, thereby controlling the state of the bidirectional DC-DC converter, switching the electric energy state of the drive motor, the battery pack 1 and the battery pack 2 and realizing energy recovery. The beneficial effect of the present invention is that it can effectively solve the problem that the operating environment of the mining electric locomotive is complex and the existing locomotive energy recovery cannot be applied.

Description

Technical field:

[0001] The present invention belongs to the technical field of energy-saving application of mining equipment, and more specifically relates to a decomposition battery type mining electric locomotive energy recovery device and a control method. Background technology:

[0002] Electric locomotives are the main equipment for mine transportation. They have a single operating path and are often in uphill and downhill operating states. At present, most domestic mining battery electric locomotives use resistors and chopper speed regulation, and have no energy feedback device during motor operation. Mechanical braking or energy consumption braking is generally used. Therefore, for electric locomotives that travel between two places with a large absolute height difference, on the one hand, when the motor goes uphill, it will consume more electricity, which brings a greater challenge to the endurance of the electric locomotive, increases the number of charging times for the electric locomotive, and seriously affects the operating efficiency; on the other hand, when the electric locomotive is running downhill with heavy load for a long time, whether it is mechanical braking or energy consumption braking, the life of the key components of the electric locomotive is reduced.

[0003] To solve the above problems, most of the current structures adopt electro-hydraulic braking, bidirectional AC-DC or single-phase AC-DC with inverter, and most of them use more mechanical switches to switch the operating state, which inevitably leads to the complex structure of the entire feedback drive device, unclear braking and feedback logic and low energy recovery efficiency, which is not suitable for the safe operation of mining electric locomotives.

[0004] The present invention provides a decomposed battery type mining electric locomotive energy recovery device and an implementation method thereof. By decomposing the battery and adopting a bidirectional DC-DC converter, only one diode is used to realize the working switching of two groups of batteries, which better overcomes the shortcomings of the prior art. Summary of the invention:

[0005] In order to solve the above problems and overcome the shortcomings of the prior art, the present invention provides a decomposable battery-type mining electric locomotive energy recovery device and control method, which can effectively solve the problem that the operating environment of mining electric locomotives is complex and the existing locomotive energy recovery is not applicable.

[0006] The specific technical solution of the present invention to solve the above technical problems is: a decomposed battery-type mining electric locomotive energy recovery device includes a battery pack 1 and a battery pack 2, characterized in that the terminal voltage U1 of the battery pack 1 is greater than the terminal voltage U2 of the battery pack 2, and the terminal voltage U1 of the battery pack 1 meets the requirements of the inverter for the DC bus voltage,

[0007] The positive terminal (+) of the output of the battery pack 1 is connected to the anode of the power diode, the cathode of the diode is connected to the positive terminal P of the DC bus of the inverter, and is also connected to the C terminal of the bidirectional DC-DC converter, and the output terminal of the inverter is connected to the electric locomotive drive motor; the negative terminal of the battery pack 1 is directly connected to the N terminal of the DC bus of the inverter and is also connected in parallel to the D terminal of the bidirectional DC-DC device.

[0008] Among them, the positive terminal (+) of the output of the battery pack 2 is connected in series with a Hall current sensor and the negative terminal (-) is respectively connected to the A and B terminals of the bidirectional DC-DC circuit, and a Hall voltage sensor is connected in parallel between A and B. The output signals of the two sensors are respectively connected to the AD sampling terminal 1 and AD sampling terminal 2 of the controller.

[0009] Furthermore, the battery pack 1 and the battery pack 2 are both provided with a battery management system (BMS) device, and the two BMSs communicate with the controller via two buses CAN_H and CAN_L, using the CAN communication protocol.

[0010] Furthermore, the controller and the frequency converter establish communication via two communication lines 485+ and 485-.

[0011] The control method of the decomposition battery type mining electric locomotive energy recovery device adopts the decomposition battery type mining electric locomotive energy recovery device. According to the actual application scenarios of the mining electric locomotive and the uphill and downhill states of the electric locomotive, the controller controls the inverter to switch the electric state or the power generation state of the drive motor through the communication line. At the same time, the controller reads the BMS remaining power information (SOC) of the battery pack 2 through the CAN bus, thereby controlling the state of the bidirectional DC-DC converter, switching the power state of the drive motor, the battery pack 1 and the battery pack 2, and realizing energy recovery.

[0012] The control method of the decomposition battery type mining electric locomotive energy recovery device specifically includes:

[0013] When the electric locomotive is in the uphill stage, if the SOC of battery pack 2 is greater than 20% and less than 100%, the bidirectional DC-DC converter is controlled to be in a boost state, that is, energy flows from the AB side to the CD side of the bidirectional DC-DC converter. To ensure that the battery pack 1 is in a natural shutdown state when the battery pack 2 is working, the output voltage Ucd of the bidirectional DC-DC converter is controlled to be slightly higher than the voltage across the battery pack 1, so that the power diode VR is in a reverse blocking state;

[0014] When the electric locomotive is in the uphill stage, if the SOC of battery pack 2 is greater than 0 and less than 20%, the bidirectional DC-DC converter is controlled to stop working. Since the output voltage of the bidirectional DC-DC converter is slightly higher than the voltage of battery pack 1 before it stops working, the energy required to drive the motor is naturally switched from the bidirectional DC-DC converter to battery pack 1, achieving a smooth transition;

[0015] When the electric locomotive is in the downhill stage, and the power of the battery pack 2 is greater than 0 and less than 100%, the controller controls the inverter to work in the braking power generation state, and controls the bidirectional DC-DC converter to work in the step-down state. According to the different power of the battery pack 2, when the charging current and the charging voltage do not exceed the allowable value, the bus voltage is maintained constant as the control target, and the bus voltage value is kept greater than the terminal voltage of the battery pack 1. The bidirectional DC-DC converter adopts a constant current or constant voltage control strategy according to the remaining power state of the battery pack 2 and the amount of feedback energy, and stores the electric energy generated by the electric locomotive running downhill in the battery pack 2 to realize electric energy recovery; if the power of the electric energy generated by the electric locomotive downhill is greater than the maximum recovery capacity of the battery pack 2, by controlling the conduction of VT3 and controlling its conduction duty cycle, the excess energy is dynamically consumed through the resistor R2 to maintain the stability of the DC voltage;

[0016] When the electric locomotive is in the downhill stage, if the power in battery pack 2 reaches 100%, the bidirectional DC-DC converter is controlled to stop working, and at the same time, a command is sent to the inverter through 485+ and 485-, so that the motor is still controlled in the power generation state, and the generated electric energy is consumed by the braking resistor inside the inverter to achieve energy-consuming braking.

[0017] The beneficial effects of the present invention are:

[0018] 1. The present invention creatively sets a decomposition battery type mining electric locomotive energy recovery device with a bidirectional DC-DC converter circuit, thereby realizing decomposition battery type mining electric locomotive energy recovery;

[0019] The present invention creatively sets up a decomposed battery type mining electric locomotive energy recovery device with a bidirectional DC-DC converter circuit. According to the actual application of the mining electric locomotive and the uphill and downhill states of the electric locomotive, the controller controls the frequency converter to switch the electric state or the power generation state of the drive motor through the communication line. At the same time, the controller reads the BMS remaining power information (SOC) of the battery pack 2 through the CAN bus, thereby controlling the state of the bidirectional DC-DC converter, switching the power state of the drive motor, the battery pack 1 and the battery pack 2, and realizing energy recovery. Description of the drawings:

[0020] Attached Figure 1 This is a circuit diagram of a decomposition battery type mining electric locomotive energy recovery device of the present invention;

[0021] Attached Figure 2 It is a bidirectional DC-DC converter circuit diagram; Specific implementation method:

[0022] In the description of the present invention, specific details are only for a full understanding of the embodiments of the present invention, but those skilled in the art should know that the implementation of the present invention is not limited to these details. In addition, well-known structures and functions are not described or shown in detail to avoid blurring the key points of the embodiments of the present invention. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] Specific implementation of the present invention:

[0024] In order to better understand the present invention, a specific embodiment is used for illustration. It is worth emphasizing that the effect of this embodiment is not substantially different from the various embodiments within the protection scope of the present invention, including the respective reagents and the content ratio of the reagents, and all of them can achieve the effects described in the present invention and solve the above-mentioned problems. Other combinations are not described here.

[0025] As an embodiment of the present invention:

[0026] The decomposition battery type mining electric locomotive energy recovery device comprises a battery pack 1 and a battery pack 2, wherein the terminal voltage U1 of the battery pack 1 is greater than the terminal voltage U2 of the battery pack 2, and the terminal voltage U1 of the battery pack 1 meets the requirements of the inverter for the DC bus voltage.

[0027] The positive terminal (+) of the output of the battery pack 1 is connected to the anode of the power diode, the cathode of the diode is connected to the positive terminal P of the DC bus of the inverter, and is also connected to the C terminal of the bidirectional DC-DC converter, and the output terminal of the inverter is connected to the electric locomotive drive motor; the negative terminal of the battery pack 1 is directly connected to the N terminal of the DC bus of the inverter and is also connected in parallel to the D terminal of the bidirectional DC-DC device;

[0028] As a creative setting of the present invention, the bidirectional DC-DC converter of the present invention has an original circuit connection structure, specifically: the A end of the bidirectional DC-DC converter is connected to one end of the inductor L, the other end of the inductor L is connected to the resistor R1, the other end of the resistor R1 is provided with the emitter of the power device VT1, one end of the resistor R2 and the collector of the power device VT2; the collector of the VT1 is connected to the C end, the emitter of the VT2 is simultaneously connected to the B end and the D end, the other end of the resistor R2 is connected to the collector of the power device VT3, and its emitter is connected to the D end, the capacitor C1 is connected in parallel between the A end and the B end, and the capacitor C2 is connected in parallel between the C end and the D end, and the gates of the three power devices are respectively connected to the control signal 1, the control signal 2 and the control signal 3.

[0029] Among them, the positive terminal (+) of the output of the battery pack 2 is connected in series with a Hall current sensor and the negative terminal (-) is respectively connected to the A and B terminals of the bidirectional DC-DC circuit, and a Hall voltage sensor is connected in parallel between A and B. The output signals of the two sensors are respectively connected to the AD sampling terminal 1 and AD sampling terminal 2 of the controller.

[0030] Furthermore, the battery pack 1 and the battery pack 2 are both provided with a battery management system (BMS) device, and the two BMSs communicate with the controller via two buses CAN_H and CAN_L, using the CAN communication protocol.

[0031] As a supplement: the controller and the inverter establish communication through two communication lines 485+ and 485-.

[0032] In addition, the present invention also includes a control method for a decomposition battery type mining electric locomotive energy recovery device, which adopts the above-mentioned decomposition battery type mining electric locomotive energy recovery device, and its core lies in: according to the actual application occasions of the mining electric locomotive, according to whether the electric locomotive is in an uphill or downhill state, the controller controls the inverter through the communication line to switch the electric state or the power generation state of the drive motor, and at the same time, the controller reads the BMS remaining power information (SOC) of the battery pack 2 through the CAN bus, thereby controlling the state of the bidirectional DC-DC converter, switching the power state of the drive motor, the battery pack 1 and the battery pack 2 and realizing energy recovery, thereby solving the problem that the operating environment of the mining electric locomotive is complex and the existing locomotive energy recovery cannot be applied;

[0033] The control method of the decomposition battery type mining electric locomotive energy recovery device is specifically:

[0034] When the electric locomotive is in the uphill stage, if the SOC of battery pack 2 is greater than 20% and less than 100%, the bidirectional DC-DC converter is controlled to be in a boost state, that is, energy flows from the AB side to the CD side of the bidirectional DC-DC converter. To ensure that the battery pack 1 is in a natural shutdown state when the battery pack 2 is working, the output voltage Ucd of the bidirectional DC-DC converter is controlled to be slightly higher than the voltage across the battery pack 1, so that the power diode VR is in a reverse blocking state;

[0035] When the electric locomotive is in the uphill stage, if the SOC of battery pack 2 is greater than 0 and less than 20%, the bidirectional DC-DC converter is controlled to stop working. Since the output voltage of the bidirectional DC-DC converter is slightly higher than the voltage of battery pack 1 before it stops working, the energy required to drive the motor is naturally switched from the bidirectional DC-DC converter to battery pack 1, achieving a smooth transition;

[0036] When the electric locomotive is in the downhill stage, and the power of the battery pack 2 is greater than 0 and less than 100%, the controller controls the inverter to work in the braking power generation state, and controls the bidirectional DC-DC converter to work in the step-down state. According to the different power of the battery pack 2, when the charging current and the charging voltage do not exceed the allowable value, the bus voltage is maintained constant as the control target, and the bus voltage value is kept greater than the terminal voltage of the battery pack 1. The bidirectional DC-DC converter adopts a constant current or constant voltage control strategy according to the remaining power state of the battery pack 2 and the amount of feedback energy, and stores the electric energy generated by the electric locomotive running downhill in the battery pack 2 to realize electric energy recovery; if the power of the electric energy generated by the electric locomotive downhill is greater than the maximum recovery capacity of the battery pack 2, by controlling the conduction of VT3 and controlling its conduction duty cycle, the excess energy is dynamically consumed through the resistor R2 to maintain the stability of the DC voltage;

[0037] When the electric locomotive is in the downhill stage, if the power in battery pack 2 reaches 100%, the bidirectional DC-DC converter is controlled to stop working, and at the same time, a command is sent to the inverter through 485+ and 485-, so that the motor is still controlled in the power generation state, and the generated electric energy is consumed by the braking resistor inside the inverter to achieve energy-consuming braking.

[0038] As a further preferred embodiment of the present invention, in order to realize the use of the actual application scenarios of the mining electric locomotive, according to the uphill and downhill states of the electric locomotive, the controller controls the frequency converter through the communication line to switch the electric state or the power generation state of the drive motor, and at the same time, can realize the switching of constant voltage power supply and constant current charging. The bidirectional DC-DC converter of the present invention can also adopt a control strategy, that is, according to the characteristics of the load connected to the bidirectional DC-DC converter, by comparing the instantaneous value of the current collected by the Hall current sensor and the instantaneous value of the voltage of the Hall voltage sensor, different control methods are adopted to realize the switching of constant voltage power supply and constant current charging; thereby adopting a constant current or constant voltage control strategy to realize stable energy recovery of the decomposed battery-type mining electric locomotive.

[0039] Specifically: the control strategy adopted by the bidirectional DC-DC converter is:

[0040] When the bidirectional DC-DC converter is in the boost power supply working mode, that is, when the energy flows from the AB side to the CD side, the controller controls VT1 to be in the off state, and maintains the output voltage Ucd of the bidirectional DC-DC converter at a constant value by controlling the ratio of the on time and the off time of VT2 (duty cycle), thereby realizing constant voltage power supply;

[0041] When the bidirectional DC-DC converter is in the step-down charging mode, that is, when the energy flows from the CD side to the AB side, the controller controls VT2 to be in the off state. According to the charging requirements of the BMS of the battery pack 2, the ratio of the on time and the off time of VT1 (duty cycle) is controlled to complete the switching of the constant voltage or constant current charging of the battery.

[0042] In summary:

[0043] 1. The present invention creatively sets a decomposition battery type mining electric locomotive energy recovery device with a bidirectional DC-DC converter circuit, thereby realizing decomposition battery type mining electric locomotive energy recovery;

[0044] The present invention creatively sets up a decomposed battery type mining electric locomotive energy recovery device with a bidirectional DC-DC converter circuit. According to the actual application of the mining electric locomotive and the uphill and downhill states of the electric locomotive, the controller controls the frequency converter to switch the electric state or the power generation state of the drive motor through the communication line. At the same time, the controller reads the BMS remaining power information (SOC) of the battery pack 2 through the CAN bus, thereby controlling the state of the bidirectional DC-DC converter, switching the power state of the drive motor, the battery pack 1 and the battery pack 2, and realizing energy recovery.

[0045] 3. The bidirectional DC-DC converter of the present invention also adopts a control strategy, that is, according to the characteristics of the load connected to the bidirectional DC-DC converter, by comparing the instantaneous value of the current collected by the Hall current sensor and the instantaneous value of the voltage of the Hall voltage sensor, different control methods are adopted to achieve the switching of constant voltage power supply and constant current charging, and then a constant current or constant voltage control strategy is adopted to achieve energy recovery of the decomposed battery-type mining electric locomotive.

Claims

1. A decomposition battery type mining electric locomotive energy recovery device, comprising a battery pack 1 and a battery pack 2, characterized in that The terminal voltage U1 of the battery pack 1 is greater than the terminal voltage U2 of the battery pack 2. The terminal voltage U1 of the battery pack 1 meets the requirements of the inverter for the DC bus voltage. The positive terminal + of the output of the battery pack 1 is connected to the anode of the power diode, the cathode of the diode is connected to the positive terminal P of the DC bus of the inverter, and is also connected to the C terminal of the bidirectional DC-DC converter, and the output terminal of the inverter is connected to the electric locomotive drive motor; the negative terminal of the battery pack 1 is directly connected to the N terminal of the DC bus of the inverter and is also connected in parallel to the D terminal of the bidirectional DC-DC device; The positive terminal + of the output of the battery pack 2 is connected in series with a Hall current sensor, and the negative terminal - is respectively connected to the A and B terminals of the bidirectional DC-DC circuit, and a Hall voltage sensor is connected in parallel between A and B. The output signals of the two sensors are respectively connected to the AD sampling terminal 1 and AD sampling terminal 2 of the controller; The battery pack 1 and the battery pack 2 are both provided with a battery management system BMS device, and the two BMSs communicate with the controller via two buses CAN_H and CAN_L, using the CAN communication protocol; The A end of the bidirectional DC-DC converter is connected to one end of the inductor L, the other end of the inductor L is connected to the resistor R1, the other end of the resistor R1 is provided with the emitter of the power device VT1, one end of the resistor R2 and the collector of the power device VT2; the collector of the VT1 is connected to the C end, the emitter of VT2 is connected to the B end and the D end at the same time, the other end of the resistor R2 is connected to the collector of the power device VT3, the emitter is connected to the D end, the capacitor C1 is connected in parallel between the A end and the B end, the capacitor C2 is connected in parallel between the C end and the D end, and the gates of the three power devices are respectively connected to the control signal 1, the control signal 2 and the control signal 3.

2. The decomposition battery type mining electric locomotive energy recovery device according to claim 1 is characterized in that The controller and the frequency converter establish communication via two communication lines 485+ and 485-.

3. A control method for decomposing a battery-type mining electric locomotive energy recovery device, characterized in that The decomposed battery type mining electric locomotive energy recovery device as described in claim 1 or 2 is adopted. According to the actual application scenarios of the mining electric locomotive and the uphill or downhill state of the electric locomotive, the controller controls the inverter to switch the electric state or the power generation state of the drive motor through the communication line. At the same time, the controller reads the BMS remaining power information SOC of the battery pack 2 through the CAN bus, thereby controlling the state of the bidirectional DC-DC converter, switching the power state of the drive motor, battery pack 1 and battery pack 2, and realizing energy recovery.

4. The control method of the decomposition battery type mining electric locomotive energy recovery device according to claim 3 is characterized in that: When the electric locomotive is in the uphill stage, if the SOC of battery pack 2 is greater than 20% and less than 100%, the bidirectional DC-DC converter is controlled to be in the boost state, that is, the energy flows from the AB side to the CD side of the bidirectional DC-DC converter. To ensure that the battery pack 1 is in the natural shutdown state when the battery pack 2 is working, the output voltage Ucd of the bidirectional DC-DC converter is controlled to be slightly higher than the voltage across the battery pack 1, so that the power diode VR is in the reverse blocking state; When the electric locomotive is in the uphill stage, if the SOC of battery pack 2 is greater than 0 and less than 20%, the bidirectional DC-DC converter is controlled to stop working. Since the output voltage of the bidirectional DC-DC converter is slightly higher than the voltage of battery pack 1 before it stops working, the energy required to drive the motor is naturally switched from the bidirectional DC-DC converter to battery pack 1, achieving a smooth transition; When the electric locomotive is in the downhill stage, and the power of the battery pack 2 is greater than 0 and less than 100%, the controller controls the inverter to work in the braking power generation state, and controls the bidirectional DC-DC converter to work in the step-down state. According to the different power of the battery pack 2, when the charging current and the charging voltage do not exceed the allowable value, the bus voltage is maintained constant as the control target, and the bus voltage value is kept greater than the terminal voltage of the battery pack 1. The bidirectional DC-DC converter adopts a constant current or constant voltage control strategy according to the remaining power state of the battery pack 2 and the amount of feedback energy, and stores the electric energy generated by the electric locomotive running downhill in the battery pack 2 to realize electric energy recovery; if the power of the electric energy generated by the electric locomotive running downhill is greater than the maximum recovery capacity of the battery pack 2, by controlling the conduction of VT3 and controlling its conduction duty cycle, the excess energy is dynamically consumed through the resistor R2 to maintain the stability of the DC voltage; When the electric locomotive is in the downhill stage, if the power in battery pack 2 reaches 100%, the bidirectional DC-DC converter is controlled to stop working, and at the same time, a command is sent to the inverter through 485+ and 485-, so that the motor is still controlled in the power generation state, and the generated electric energy is consumed by the braking resistor inside the inverter to achieve energy-consuming braking.

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