CN112383075B - An energy management control device for a common DC bus multi-machine operation energy storage system - Google Patents

Abstract

The invention discloses an energy management control device of a common direct current bus multi-machine operation energy storage system, which adopts common direct current bus energy storage control to acquire information such as voltage, current, power and the like of a bus side, a super capacitor module side and a motor side in real time by considering the problems of complex load operation condition and large energy consumption of a plurality of motor driving systems, carries out state identification and power tracking, and intensively controls and manages energy through a dynamic power feedforward compensation strategy, thereby not only completing self-consumption of energy between loads, but also realizing energy coordination distribution and stable operation of a motor in braking and electric states and improving the energy utilization rate of the system. The energy-saving control method is suitable for occasions of energy-saving control of multi-motor driving systems of textile, papermaking, steel rolling, stacking machines and the like.

Description

An energy management control device for a common DC bus multi-machine operation energy storage system

technical field

The invention belongs to the technical field of energy-saving control, and in particular relates to an energy management control device for a common DC bus multi-machine operation energy storage system.

Background technique

With the improvement of industrial production automation, multi-motor drive systems are widely used in control systems such as textiles, papermaking, steel rolling, and stackers. In the driving process of each motor, there are electric and braking operation states, and the energy generated by the braking operation is mostly consumed in the form of heat, resulting in a large energy loss. An effective method is to use a common DC bus to centrally control and manage energy to achieve self-consumption of energy between loads, which can greatly improve the energy utilization rate of the system. However, this method still has the situation that the braking energy is too large and the system cannot consume itself. The excess braking energy will still cause the energy at the DC bus to accumulate, thereby causing the DC bus voltage to pump up.

At present, the existing solutions are: first, the DC bus consumes the excess energy of the DC bus in the form of heat through the braking unit, which can ensure the safe and normal operation of the system, but the braking unit configuration cannot meet the system load change in real time. demand, the energy loss is relatively large. Second, the excess energy is fed back to the grid through the feedback unit to achieve energy saving, but this will cause grid voltage fluctuations and increase the harmonic content, which will reduce the quality of the grid.

SUMMARY OF THE INVENTION

The invention provides an energy management and control device for a common DC bus multi-machine operation energy storage system, which aims to solve the drawbacks of the existing device, and discloses a common DC bus multi-machine operation storage system capable of directly recovering and reusing braking energy. Energy system energy management control device. Energy-saving control for multi-motor drive systems.

In order to solve the above technical problems, the present invention provides an energy management and control device for a common DC bus multi-machine operation energy storage system, including a main circuit unit, a signal acquisition unit and a control unit, wherein the main circuit unit includes a three-phase rectifier, filter capacitor, braking unit, first inverter, first AC motor, second inverter, second AC motor, bidirectional DC/DC converter, super capacitor module, positive DC bus, negative DC bus; The signal acquisition unit includes a first voltage sensor, a first analog-to-digital conversion circuit, a first power sensor, a second analog-to-digital conversion circuit, a second power sensor, a third analog-to-digital conversion circuit, a second voltage sensor, and a fourth analog-to-digital conversion circuit. a conversion circuit, a current sensor, and a fifth analog-to-digital conversion circuit; the control unit includes a load power calculation module, a load state judgment module, an SOC calculation module, a braking mode switch, an electric mode switch, a first voltage given module, a first voltage regulator, first adder, first current regulator, first PWM drive module, first logic operation module, first dynamic power feedforward compensation module, second voltage given module, second voltage regulator, first Two adders, a second current regulator, a second PWM drive module, a second logic operation module, a second dynamic power feedforward compensation module, a selection switch, a digital-to-analog conversion circuit, and a brake protection control module;

The U, V, W three-phase lines are correspondingly connected to the three-phase input terminals of the three-phase rectifier, and the DC+ output terminal and DC- output terminal of the three-phase rectifier are connected to the DC side of the first inverter and the first inverter through the DC bus positive and DC bus negative. On the DC side of the second inverter, a filter capacitor, a first voltage sensor and a braking unit are arranged in parallel between the positive DC bus and the negative DC bus; the AC side of the first inverter is connected to the first AC motor through the first power sensor, and the second The AC side of the inverter is connected to the second AC motor via the second power sensor; the + and - terminals of the high-voltage side of the bidirectional DC/DC converter are respectively connected to the positive and negative DC bus bars, and the low-voltage side of the bidirectional DC/DC converter + The terminal is connected to the + terminal of the supercapacitor module through a current sensor, the low-voltage side - terminal of the bidirectional DC/DC converter is directly connected to the - terminal of the supercapacitor module, and the second voltage sensor is connected in parallel with the bidirectional DC/DC converter and the supercapacitor module. between capacitor modules;

The second analog-to-digital conversion circuit is connected between the first power sensor and the load power calculation module, and the third analog-to-digital conversion circuit is connected between the second power sensor and the load power calculation module, wherein the first power sensor and the second power sensor Collect the instantaneous power values of the first AC motor and the second AC motor respectively, and input them to the load power calculation module after conversion by the second analog-to-digital conversion circuit and the third analog-to-digital conversion circuit, and the load power calculation module outputs the total power value of the motor after calculation. To the load state judgment module, the load state judgment module outputs a level signal to the selection switch port A2; the first voltage sensor collects the actual value of the bus voltage, and sends it to the first dynamic power feedforward compensation module through the first analog-to-digital conversion circuit; the second The voltage sensor collects the actual value of the supercapacitor voltage, and sends it to the first dynamic power feedforward compensation module through the fourth analog-to-digital conversion circuit; the total motor power value output by the load power calculation module is sent to the first dynamic power feedforward compensation module. The dynamic power feedforward compensation module receives three parts of data, and outputs it to the first adder after compensation operation; the first voltage regulator is based on the supercapacitor voltage reference value output by the first voltage given module and the output value of the fourth analog-to-digital conversion circuit. After the actual value of the supercapacitor voltage is adjusted, the output result is sent to the first adder. The signal output by the first adder and the actual value of the supercapacitor current output by the fifth analog-to-digital conversion circuit are both sent to the first current regulator. The first current The output signal of the regulator is generated by the first PWM drive module and then sent to the first logic operation module; the braking mode switch actually compares the SOC value of the super capacitor output from the SOC calculation module and the voltage of the super capacitor output by the fourth analog-to-digital conversion circuit. After comprehensive judgment of the value, the result is output to the first logic operation module, and the first logic operation module performs AND operation on the braking mode switch and the output signal of the first PWM drive module and then sends it to the selection switch port A1;

The bus voltage reference value given by the second voltage given module and the actual bus voltage output from the first analog-to-digital conversion circuit are both sent to the second voltage regulator, and the second voltage regulator outputs the signal to the second adder, the second The dynamic power feedforward compensation module performs a compensation operation on the actual value of the bus voltage from the first analog-to-digital conversion circuit and the total motor power value of the load power calculation module, and then the calculation result is output to the second adder, and the signal output by the second adder is sum. The actual value of the supercapacitor current output by the fifth analog-to-digital conversion circuit is sent to the second current regulator, and the output signal of the second current regulator is generated by the second PWM drive module. The PWM signal is input to the second logic operation module; the electric mode switch The comprehensive judgment of the SOC value output from the SOC calculation module and the actual value of the supercapacitor voltage output by the fourth analog-to-digital conversion circuit is also output to the second logic operation module. The second logic operation module drives the electric mode switch and the second PWM. The output signal of the module is sent to the selection switch port A3 after operation and operation. When the selection switch port A2 is a high-level signal, the selection switch is connected to the port A1. When the selection switch port A2 is a low-level signal, the selection switch is connected to the port. A3, the output of the selection switch is sent to the bidirectional DC/DC converter through the digital-to-analog conversion circuit;

The logic signal output by the braking mode switch and the actual value of the bus voltage output by the first analog-to-digital conversion circuit are sent to the braking protection control module, and the braking protection control module outputs the logic signal to the braking unit after judgment.

Compared with the prior art, the beneficial effects of the present invention are:

The energy management control device of the multi-machine operation energy storage system connects the DC sides of the inverters of each motor drive system together, and uniformly distributes and manages the energy of all the motors, which can not only realize energy consumption between multiple motors, but also Moreover, the braking energy generated during the operation of multiple motors can be comprehensively recovered and reused through the DC bus, and through the dynamic power feedforward compensation strategy, the coordinated distribution and smooth operation of the energy of the motors in braking and electric states can be realized, and the energy utilization rate can be improved. It is suitable for occasions where multi-motor drive systems such as textile, papermaking, steel rolling, stacking cranes need to improve energy utilization.

Description of drawings

FIG. 1 is a schematic diagram of an energy management control device for a common DC bus multi-machine operation energy storage system provided by the present invention.

In the figure: 1. Three-phase rectifier; 2. Filter capacitor; 3. Braking unit; 4. First inverter; 5. First AC motor; 6. Second inverter; 7. Second AC motor; 8. Bidirectional DC/DC converter; 9. Super capacitor module; 10. First voltage sensor; 11. First analog-to-digital conversion circuit; 12. First power sensor; 13. Second analog-to-digital conversion circuit; 14. 15. Third analog-to-digital conversion circuit; 16. Second voltage sensor; 17. Fourth analog-to-digital conversion circuit; 18. Current sensor; 19. Fifth analog-to-digital conversion circuit; 20. Load power calculation module 21. Load state judgment module; 22. SOC calculation module; 23. Brake mode switch; 24. Electric mode switch; 25. First voltage given module; 26. First voltage regulator; 27. First adder ; 28. The first current regulator; 29. The first PWM drive module; 30. The first logic operation module; 31. The first dynamic power feedforward compensation module; 32. The second voltage setting module; 33. The second voltage regulator; 34. second adder; 35. second current regulator; 36. second PWM drive module; 37. second logic operation module; 38.; second dynamic power feedforward compensation module; 39. selection switch ; 40. Digital-to-analog conversion circuit; 41. Brake protection control module; 42. DC bus positive; 43. DC bus negative.

Detailed ways

The present invention is further illustrated by the following examples, but is not limited to the following examples.

Referring to FIG. 1, FIG. 1 is a schematic diagram of an energy management control device for a common DC bus multi-machine operation energy storage system provided by the present invention. The device includes: a main circuit unit, a signal acquisition unit and a control unit, the main circuit unit includes a three-phase rectifier 1, a filter capacitor 2, a braking unit 3, a first inverter 4, a first AC motor 5, a second Inverter 6, second AC motor 7, bidirectional DC/DC converter 8, super capacitor module 9, DC bus positive 42, DC bus negative 43; the signal acquisition unit includes a first voltage sensor 10, a first module Digital conversion circuit 11 , first power sensor 12 , second analog-to-digital conversion circuit 13 , second power sensor 14 , third analog-to-digital conversion circuit 15 , second voltage sensor 16 , fourth analog-to-digital conversion circuit 17 , current sensor 18 , the fifth analog-to-digital conversion circuit 19; the control unit includes a load power calculation module 20, a load state judgment module 21, an SOC calculation module 22, a braking mode switch 23, an electric mode switch 24, a first voltage given module 25, The first voltage regulator 26, the first adder 27, the first current regulator 28, the first PWM drive module 29, the first logic operation module 30, the first dynamic power feedforward compensation module 31, the second voltage given module 32. The second voltage regulator 33, the second adder 34, the second current regulator 35, the second PWM drive module 36, the second logic operation module 37, the second dynamic power feedforward compensation module 38, the selection switch 39, A digital-to-analog conversion circuit 40 , a brake protection control module 41 .

The U, V, W three-phase lines are all connected to the input terminal of the three-phase rectifier 1, and the DC+ output terminal and the DC- output terminal of the three-phase rectifier 1 are respectively connected to the first inverter through the positive DC bus 42 and the negative DC bus 43. 4. On the DC side of the second inverter 6, the filter capacitor 2, the first voltage sensor 10, and the braking unit 3 are connected in parallel between the positive 42 of the DC bus and the negative 43 of the DC bus. The power sensor 12 is connected to the first AC motor 5, and the AC side of the second inverter 6 is connected to the second AC motor 7 via the second power sensor 14; The positive 42 of the DC bus and the negative 43 of the DC bus, the low-voltage side + end of the bidirectional DC/DC converter 8 is connected to the + end of the supercapacitor module 9 through the current sensor 18, and the low-voltage side - end of the bidirectional DC/DC converter 8 is directly connected. Connected to the - end of the supercapacitor module 9 , the second voltage sensor 16 is connected in parallel between the bidirectional DC/DC converter 8 and the supercapacitor module 9 .

The first power sensor 12 and the second power sensor 14 respectively collect the instantaneous power values of the first AC motor 5 and the second AC motor 7 and input them to the load after being converted by the second analog-to-digital conversion circuit 13 and the third analog-to-digital conversion circuit 15 . The power calculation module 20, the load power calculation module 20 calculates and outputs the total power value of the motor to the load state judgment module 21, and the load state judgment module 21 outputs the level signal to the port A2 of the selection switch 39; the first voltage sensor 10 collects the actual value of the bus voltage The actual value of the supercapacitor voltage is collected via the first analog-to-digital conversion circuit 11 and the second voltage sensor 16, and the total motor power value output by the fourth analog-to-digital conversion circuit 17 and the load power calculation module 20 is sent to the first dynamic power feedforward compensation Module 31, the first dynamic power feedforward compensation module 31 outputs to the first adder 27 after compensation operation; the first voltage regulator 26 gives the supercapacitor voltage reference value and the fourth modulus output by the first voltage given module 25 The actual value of the supercapacitor voltage output by the conversion circuit 17 is also sent to the first adder 27 after being adjusted. The current regulator 28, the output signal of the first current regulator 28 is generated by the first PWM drive module 29 and sent to the first logic operation module 30; The actual value of the super capacitor voltage output by the fourth analog-to-digital conversion circuit 17 is also output to the first logic operation module 30 after comprehensive judgment. The first logic operation module 30 outputs signals to the braking mode switch 23 and the first PWM drive module 29 After the AND operation is performed, it is sent to the port A1 of the selector switch 39.

The bus voltage reference value output by the second voltage setting module 32 and the bus voltage actual value output by the first analog-to-digital conversion circuit 11 are both sent to the second voltage regulator 33, and the second voltage regulator 33 outputs the signal to the second adder the second adder 34, the second dynamic power feedforward compensation module 38 performs a compensation operation on the actual value of the bus voltage from the first analog-to-digital conversion circuit 11 and the total motor power value of the load power calculation module 20, and also outputs it to the second adder 34, The signal output by the second adder 34 and the actual value of the supercapacitor current output by the fifth analog-to-digital conversion circuit 19 are both sent to the second current regulator 35 , and the output signal of the second current regulator 35 is generated by the second PWM driving module 36 The PWM signal is input to the second logic operation module 37; the electric mode switch 24 makes a comprehensive judgment on the SOC value output from the SOC calculation module 22 and the actual value of the super capacitor voltage output by the fourth analog-to-digital conversion circuit 17 and outputs it to the second logic operation. Module 37, the second logic operation module 37 performs AND operation on the output signal of the electric mode switch 24 and the second PWM drive module 36 and sends it to the port A3 of the selection switch 39. When the port A2 of the selection switch 39 is a high level signal, the selection The switch 39 turns on the port A1, when the port A2 of the selection switch 39 is a low-level signal, the selection switch 39 turns on the port A3, and the output of the selection switch 39 is sent to the bidirectional DC/DC converter 8 through the digital-to-analog conversion circuit 40; wherein The logic signal output by the braking mode switch 23 and the actual value of the bus voltage output by the first analog-to-digital conversion circuit 11 are sent to the braking protection control module 41 , and the braking protection control module 41 outputs the logic signal to the braking unit 3 after judgment. .

In the above structure, the first power sensor 12 and the second power sensor 14 respectively collect the instantaneous power values of the first AC motor 5 and the second AC motor 7 after conversion by the second analog-to-digital conversion circuit 13 and the third analog-to-digital conversion circuit 15 . Input to the load power calculation module 20, the load power calculation module 20 outputs the total power value of the motor to the load state judgment module 21, and the calculation of the total motor power value is shown in formula (1):

Among them, P _L (t) is the total power of multiple motors at time t, and P _n (t) is the power of the corresponding nth motor at time t. This formula is also applicable to the case where n is greater than 2. When the motor is working in the braking state When , P _n (t)<0, when the motor works in the electric state, P _n (t)>0, so there are four working states for multiple motors, as follows:

State 1: Both the first AC motor 5 and the second AC motor 7 are working in the braking state. At this time, the load state judgment module 21 detects that _PL (t)<0, and outputs a high-level signal to the port A2 of the selection switch 39, The selection switch 39 is connected to the port A1, and the signal output by the first logic operation module 30 is sent to the bidirectional DC/DC converter 8 through the digital-to-analog conversion circuit 40; the first voltage sensor 10 collects the actual value of the bus voltage through the first analog-to-digital conversion. The circuit 11 and the second voltage sensor 16 collect the actual value of the supercapacitor voltage, and the total motor power value output by the fourth analog-to-digital conversion circuit 17 and the load power calculation module 20 is sent to the first dynamic power feedforward compensation module 31. The power feedforward compensation module 31 outputs the first current compensation value to the first adder 27 after the calculation of the formula (2); wherein the expression of the formula (2) is:

where i _c1 (t) is the first current compensation value at time t, ΔP ₁ is the first power feedforward compensation value, U _sc (t) is the voltage value of the supercapacitor module 9 at time t, and C _dc is the filter capacitor 2, U _d (t) is the bus voltage value at time t, _isc (t) is the current value of the supercapacitor module 9 at time t, K is the number of sampling cycles, and ΔT is the sampling cycle value.

The reference value of the supercapacitor voltage output by the first voltage setting module 25 and the actual value of the supercapacitor voltage output by the fourth analog-to-digital conversion circuit 17 are both sent to the first voltage regulator 26, and the first voltage regulator 26 is adjusted and then output to The first adder 27, the signal output by the first adder 27 and the actual value of the supercapacitor current output by the fifth analog-to-digital conversion circuit 19 are sent to the first current regulator 28, and the output signal of the first current regulator 28 is passed through the first adder 28. A PWM driving module 29 generates a PWM signal and inputs it to the first logic operation module 30 .

The fourth analog-to-digital conversion circuit 17 outputs the actual value of the supercapacitor voltage to the SOC calculation module 22, and the SOC value of the supercapacitor module 9 is calculated as formula (3):

Among them, SOC(t) is the state of charge value of the supercapacitor module 9 at time t, SOC(t ₀ ) is the state of charge value of the supercapacitor module 9 at the initial time t ₀ , and Q ₀ is the rated value of the supercapacitor module 9 Charge capacity, C is the capacitance value of the super capacitor module 9, R is the parallel equivalent resistance of the super capacitor module 9, U _sc (t ₀ ) is the voltage at the initial time t ₀ of the super capacitor module 9, U _scmin is the minimum working voltage of the supercapacitor module 9 , and U _scmax is the maximum working voltage of the supercapacitor module 9 .

The SOC value output by the SOC calculation module 22 and the actual value of the super capacitor voltage output by the fourth analog-to-digital conversion circuit 17 are both sent to the braking mode switch 23. When SOC<SOC _max &U _sc <U _scmax , where SOC _max is the super capacitor SOC upper limit value, the braking mode switch 23 outputs a logic 1 signal to the first logic operation module 30, and the first logic operation module 30 matches the logic 1 signal of the braking mode switch 23 with the PWM signal generated by the first PWM driving module 29. After that, the PWM signal is output to the port A1 of the selection switch 39, and the PWM signal output by the selection switch 39 is input to the bidirectional DC/DC converter 8 through the digital-to-analog conversion circuit 40, and the bidirectional DC/DC converter 8 starts to work in the step-down mode. The super capacitor module 9 is charged; when SOC>SOC _max or U _sc >U _scmax , the braking mode switch 23 outputs a logic 0 signal to the first logic operation module 30, and the first logic operation module 30 converts the braking mode switch 23 The logic 0 signal and the PWM signal generated by the first PWM drive module 29 are phased together and output a logic 0 signal to the port A1 of the selection switch 39. The logic 0 signal output by the selection switch 39 is converted to the bidirectional DC/DC converter 8 through the digital-to-analog conversion circuit 40. Locked, the super capacitor module 9 does not work; at this time, the logic signal output by the braking mode switch 23 and the bus voltage output by the first analog-to-digital conversion circuit 11 are both sent to the braking protection control module 41. When the braking protection control module 41 When it detects the bus voltage value U _d >600V and the logic 0 signal input by the braking mode switch 23, the braking protection control module 41 outputs the logic 1 signal to the braking unit 3 to start the braking resistor, so as to avoid the system voltage rising and causing The system is operating dangerously.

State 2: If the first AC motor 5 works in the braking state, the second AC motor 7 works in the electric state, and the braking power is greater than the electric power, at this time, the electric power required by the second AC motor 7 is completely determined by the first AC motor. The braking power of the AC motor 5 is provided, and the remaining braking power is recovered by the energy storage device. The load state judgment module 21 detects that _PL (t)<0, and outputs a high-level signal to the port A2 of the selection switch 39, and the selection switch 39 Turns on the port A1, and transmits the signal output from the first logic operation module 30 to the bidirectional DC/DC converter 8 through the digital-to-analog conversion circuit 40. The working process is the same as that of the state 1, and is not repeated here.

State 3: The first AC motor 5 and the second AC motor 7 are both working in the electric state. At this time, the load state judgment module 21 detects that _PL (t)>0, and outputs a low-level signal to the port A2 of the selection switch 39 to select The switch 39 turns on port A3, and the signal output by the second logic operation module 37 is input to the bidirectional DC/DC converter 8 through the digital-to-analog conversion circuit 40; the first voltage sensor 10 collects the actual value of the bus voltage through the first analog-to-digital conversion circuit 11 and the total motor power value output by the load power calculation module 20 are sent to the second dynamic power feedforward compensation module 38, and the second dynamic power feedforward compensation module 38 outputs the second current compensation value to the second Adder 34; wherein the expression of formula (4) is:

Its i _c2 (t) is the second current compensation value at time t, and ΔP ₂ is the second power feedforward compensation value.

The bus voltage reference value output by the second voltage setting module 32 and the bus voltage actual value output by the first analog-to-digital conversion circuit 11 are both sent to the second voltage regulator 33, and the second voltage regulator 33 outputs to the second voltage regulator 33 after adjustment. The adder 34, the signal output by the second adder 34 and the actual value of the supercapacitor current output by the fifth analog-to-digital conversion circuit 19 are all sent to the second current regulator 35, and the output signal of the second current regulator 35 is processed by the second PWM. The driving module 36 generates a PWM signal and inputs it to the second logic operation module 37 .

The SOC value output by the SOC calculation module 22 and the actual value of the super capacitor voltage output by the fourth analog-to-digital conversion circuit 17 are both sent to the electric mode switch 24. When SOC>SOC _min &U _sc >U _scmin , where SOC _min is the super capacitor SOC The lower limit value, the electric mode switch 24 outputs a logic 1 signal to the second logic operation module 37, and the second logic operation module 37 sums the logic 1 signal of the electric mode switch 23 and the PWM signal generated by the second PWM drive module 36 and outputs the result The PWM signal is sent to port A3 of the selection switch 39, and the PWM signal output by the selection switch 39 is input to the bidirectional DC/DC converter 8 through the digital-to-analog conversion circuit 40, and the bidirectional DC/DC converter 8 starts to work in the boost mode, and the super capacitor mode is Group 9 is discharged; when SOC < SOC _min or U _sc < U _scmin , the electric mode switch 24 outputs a logic 0 signal to the second logic operation module 37, and the second logic operation module 37 combines the logic 0 signal of the electric mode switch 24 with the first The PWM signals generated by the two PWM drive modules 36 are phased and output a logic 0 signal to the port A3 of the selection switch 39. The logic 0 signal output by the selection switch 39 blocks the bidirectional DC/DC converter 8 through the digital-to-analog conversion circuit 40, and the super capacitor analog Group 9 does not work. At this time, the power required by the motor load is completely provided by the power grid, and the energy storage system no longer participates in the work.

State 4: If the first AC motor 5 works in the braking state, the second AC motor 7 works in the electric state, and the electric power is more than the braking power, at this time, the braking power generated by the first AC motor 5 is all provided to the first AC motor 5. Two AC motors 7, the remaining electric power required by the second AC motor 7 is provided by the energy storage device or the power grid, and the load state judgment module 21 detects that _PL (t)>0, and outputs a low-level signal to the port A2 of the selection switch 39 , the selection switch 39 turns on the port A3, and the output signal of the second logic operation module 37 is sent to the bidirectional DC/DC converter 8 through the digital-to-analog conversion circuit 40.

The above embodiment has been described in the dual-motor drive system, and the embodiment is also applicable in three or more motor systems, and will not be described in detail here.

The above are only the embodiments of the present invention, and are not intended to limit the scope of the patent of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the description and drawings of the present invention, or directly or indirectly applied in other related technical fields, All are similarly included in the scope of patent protection of the present invention.

Claims (1)

1. The energy management control device of the common direct current bus multi-machine operation energy storage system is characterized by comprising a main circuit unit, a signal acquisition unit and a control unit, wherein the main circuit unit comprises a three-phase rectifier (1), a filter capacitor (2), a brake unit (3), a first inverter (4), a first alternating current motor (5), a second inverter (6), a second alternating current motor (7), a bidirectional DC/DC converter (8), a super capacitor module (9), a direct current bus positive (42) and a direct current bus negative (43); the signal acquisition unit comprises a first voltage sensor (10), a first analog-to-digital conversion circuit (11), a first power sensor (12), a second analog-to-digital conversion circuit (13), a second power sensor (14), a third analog-to-digital conversion circuit (15), a second voltage sensor (16), a fourth analog-to-digital conversion circuit (17), a current sensor (18) and a fifth analog-to-digital conversion circuit (19); the control unit comprises a load power calculation module (20), a load state judgment module (21), an SOC calculation module (22), a brake mode switch (23), an electric mode switch (24), a first voltage setting module (25), a first voltage regulator (26), a first adder (27), a first current regulator (28), a first PWM driving module (29), a first logic operation module (30), a first dynamic power feedforward compensation module (31), a second voltage setting module (32), a second voltage regulator (33), a second adder (34), a second current regulator (35), a second PWM driving module (36), a second logic operation module (37), a second dynamic power feedforward compensation module (38), a selection switch (39), a digital-to-analog conversion circuit (40) and a brake protection control module (41);

u, V, W three phase lines are correspondingly connected to the three-phase input end of the three-phase rectifier (1), the DC + output end and the DC-output end of the three-phase rectifier (1) are connected to the DC side of the first inverter (4) and the DC side of the second inverter (6) through the positive (42) and the negative (43) of the DC bus, and a filter capacitor (2), a first voltage sensor (10) and a brake unit (3) are arranged in parallel between the positive (42) and the negative (43) of the DC bus; the alternating current side of the first inverter (4) is connected to the first alternating current motor (5) through a first power sensor (12), and the alternating current side of the second inverter (6) is connected to the second alternating current motor (7) through a second power sensor (14); the high-voltage side + end and the high-voltage side-end of the bidirectional DC/DC converter (8) are respectively connected with a direct-current bus positive (42) and a direct-current bus negative (43), the low-voltage side + end of the bidirectional DC/DC converter (8) is connected with the + end of the super capacitor module (9) through a current sensor (18), the low-voltage side-end of the bidirectional DC/DC converter (8) is directly connected with the-end of the super capacitor module (9), and a second voltage sensor (16) is connected between the bidirectional DC/DC converter (8) and the super capacitor module (9) in parallel;

the second analog-to-digital conversion circuit (13) is connected between the first power sensor (12) and the load power calculation module (20), the third analog-to-digital conversion circuit (15) is connected between the second power sensor (14) and the load power calculation module (20), wherein the first power sensor (12) and the second power sensor (14) respectively collect power instantaneous values of the first alternating current motor (5) and the second alternating current motor (7), the power instantaneous values are converted by the second analog-to-digital conversion circuit (13) and the third analog-to-digital conversion circuit (15) and then input into the load power calculation module (20), the load power calculation module (20) outputs a total power value of the motors to the load state judgment module (21) after calculation, and the load state judgment module (21) outputs a level signal to a port A2 of the selector switch (39); the method comprises the following steps that a first voltage sensor (10) collects a bus voltage actual value and transmits the bus voltage actual value to a first dynamic power feedforward compensation module (31) through a first analog-to-digital conversion circuit (11); a second voltage sensor (16) collects the actual voltage value of the super capacitor and transmits the actual voltage value to a first dynamic power feedforward compensation module (31) through a fourth analog-to-digital conversion circuit (17); the total power value of the motor output by the load power calculation module (20) is transmitted to a first dynamic power feedforward compensation module (31), and the first dynamic power feedforward compensation module (31) receives the three parts of data and outputs the data to a first adder (27) after compensation operation; the first voltage regulator (26) regulates according to a super capacitor voltage reference value output by the first voltage setting module (25) and a super capacitor voltage actual value output by the fourth analog-to-digital conversion circuit (17), then outputs a result to the first adder (27), signals output by the first adder (27) and the super capacitor current actual value output by the fifth analog-to-digital conversion circuit (19) are both transmitted to the first current regulator (28), and signals output by the first current regulator (28) are transmitted to the first logic operation module (30) through the first PWM driving module (29) to generate PWM signals; the braking mode switch (23) carries out comprehensive judgment on the SOC value of the super capacitor output from the SOC calculation module (22) and the actual value of the voltage of the super capacitor output from the fourth analog-to-digital conversion circuit (17), and then the result is output to the first logic operation module (30), and the first logic operation module (30) carries out AND operation on the output signals of the braking mode switch (23) and the first PWM driving module (29) and then sends the output signals to a port A1 of the selector switch (39);

the bus voltage reference value given by the second voltage given module (32) and the bus voltage actual value output by the first analog-digital conversion circuit (11) are both transmitted to a second voltage regulator (33), a second voltage regulator (33) outputs a signal to a second adder (34), a second dynamic power feedforward compensation module (38) performs compensation operation on the actual value of the bus voltage from the first analog-to-digital conversion circuit (11) and the total power value of the motor of the load power calculation module (20) and outputs a calculation result to the second adder (34), the signal output by the second adder (34) and the actual value of the super capacitor current output by the fifth analog-to-digital conversion circuit (19) are both transmitted to a second current regulator (35), and the output signal of the second current regulator (35) generates a PWM signal through a second PWM driving module (36) and inputs the PWM signal to a second logic operation module (37); the electric mode switch (24) comprehensively judges the SOC value output by the SOC calculation module (22) and the actual value of the super capacitor voltage output by the fourth analog-to-digital conversion circuit (17) and outputs the SOC value and the actual value of the super capacitor voltage to the second logic operation module (37), the second logic operation module (37) performs AND operation on output signals of the electric mode switch (24) and the second PWM driving module (36) and then sends the output signals to a port A3 of a selector switch (39), the selector switch (39) turns on a port A1 when the port A2 of the selector switch (39) is a high-level signal, the selector switch (39) turns on a port A3 when the port A2 of the selector switch (39) is a low-level signal, and the output of the selector switch (39) is sent to the bidirectional DC/DC converter (8) through a digital-to-analog conversion circuit (40);

logic signals output by the brake mode switch (23) and actual bus voltage values output by the first analog-to-digital conversion circuit (11) are both transmitted to the brake protection control module (41), and the brake protection control module (41) outputs logic signals to the brake unit (3) after judgment.

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