Direct current port control circuit, local controller, control method and energy router

Abstract

The invention relates to the technical field of power electronics, in particular to a direct current port control circuit, a local controller, a control method and an energy router. Voltage control unit instruction voltage output by a voltage slow start unit is tracked through a voltage control unit, after further voltage stabilization, a phase shift angle control signal of the voltage control unit is obtained, direct current bus instruction power is tracked through a current control unit, processing operation is carried out, and a phase shift angle control signal of the current control unit is obtained. And the mode switching unit obtains a corresponding phase-shifting angle control signal of the voltage control unit and a phase-shifting angle control signal of the current control unit, carries out operation, generates a corresponding PWM signal and outputs the PWM signal to the direct-current port, thereby regulating and controlling an initial value voltage of the direct-current port to a final value voltage of the direct-current bus. Meanwhile, when the power grid breaks down and the energy storage SOC is about to reach the upper limit value, the mode switching unit is switched to the voltage slow start unit, and the voltage control unit works, so that the voltage of the direct current port side is quickly regulated and controlled.

Description

Technical Field

[0001] The present invention relates to the field of power electronics technology, and in particular to a DC port control circuit, a local controller, a control method and an energy router. Background Art

[0002] In order to meet the complexity and diversity of power control requirements of future power grids, energy routers have come into being. Energy routers can achieve efficient access and utilization of energy, and will become the core component of future power grids. They are receiving more and more attention.

[0003] In practical applications, the diversity of energy router ports brings about the complexity of operating conditions. To ensure the reliability of DC bus voltage control, each port of the energy router should have a certain self-capability that is independent of communication distribution to ensure that the DC bus voltage of the energy router is stable under sudden working conditions.

[0004] The DC port is the link for quantitative energy interaction between the grid-connected energy router and the external DC source. Its transmission power and control strategy often need to be coordinated with the external DC source. However, load overload, photovoltaic overcharging, grid failure and other working conditions are highly random and sudden, and generally last for a short time. It is impossible to maintain the power balance on the DC bus by adjusting the transmission power of the DC port in real time. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a DC port control circuit, a local controller, a control method and an energy router.

[0006] To achieve the above object, the present invention provides a DC port control circuit, comprising:

[0007] Mode switching unit, voltage slow start unit, voltage control unit, current control unit;

[0008] The voltage slow start unit is connected to the voltage control unit, and the voltage control unit and the current control unit are both connected to the mode switching unit;

[0009] The mode switching unit obtains a mode switching signal. When the mode switching signal is a voltage control unit working signal, a path is formed between the voltage slow start unit, the voltage control unit and the mode switching unit. The voltage slow start unit obtains the current value voltage of the DC bus and the final value voltage of the DC bus, performs several slow start operations, obtains the voltage control unit command voltage, and outputs the voltage control unit command voltage to the voltage control unit.

[0010] The voltage control unit obtains the voltage control unit command voltage, the DC bus current value voltage, and the load reference current to perform calculations to obtain a phase shift angle control signal of the voltage control unit, and outputs the phase shift angle control signal of the voltage control unit to the mode switching unit;

[0011] When the mode switching signal is a working signal of the current control unit, a path is formed between the current control unit and the mode switching unit, the current control unit obtains the DC bus command power, the DC bus current value voltage, and the load reference current to perform calculations to obtain a phase shift angle control signal of the current control unit, and outputs the phase shift angle control signal of the current control unit to the mode switching unit;

[0012] The mode switching unit obtains a mode switching signal, and accordingly, calculates the obtained phase shift angle control signal of the voltage control unit and the phase shift angle control signal of the current control unit to generate a corresponding PWM signal and outputs it to the DC port, thereby regulating the initial value voltage of the DC port to the final value voltage of the DC bus.

[0013] Optionally, the step of the voltage slow-start unit performing a slow-start operation includes:

[0014] Step S1, determining whether the mode switching signal is a voltage control unit working signal, if the mode switching signal is not a voltage control unit working signal, executing step S2; if the mode switching signal is a voltage control unit working signal, executing step S3;

[0015] Step S2, the voltage slow start unit does not work;

[0016] Step S3, judging whether the current value voltage of the DC bus is equal to the final value voltage of the DC bus; if the current value voltage of the DC bus is equal to the final value voltage of the DC bus, the ramp instruction is set to be not equal to 0, and step S4 is executed; if the current value voltage of the DC bus is not equal to the final value voltage of the DC bus, the ramp instruction is set to 0, and step S5 is executed;

[0017] Step S4, the DC bus current voltage is equal to the DC bus final voltage, the ramp instruction is set to 1, the output voltage control unit instruction voltage is output, the DC bus current voltage is adjusted, and step S1 is continued;

[0018] Step S5, determining whether the voltage slow start unit 10 has completed initialization. If the voltage slow start unit 10 has not been initialized, setting the initialization instruction to 0, and executing step 6; if the voltage slow start unit 10 has completed initialization and the initialization instruction is not 0, executing step 7;

[0019] Step S6, initializing the voltage slow start unit, wherein:

[0020] The current voltage of the DC bus is set as the initial voltage of the voltage slow start unit, the final voltage of the DC bus is the final value of the slow start operation of the voltage slow start unit, the slow start cycle number of the slow start operation is set to N, and the slow start count value is set to n i , the first slow start count value n1=0, set the initialization instruction to 1, and execute step 7;

[0021] Step S7, execute n i +1, go to step S8;

[0022] Step S8, determine n i +1 is greater than or equal to the number of slow-start cycles N of the slow-start operation. If the n i +1 is greater than or equal to the number of slow-start cycles N of the slow-start operation, then execute step S4; if the n i +1 is less than the number of slow-start cycles N of the slow-start operation, then execute step S9;

[0023] Step S9, obtaining the voltage control unit command voltage through a slow-start operation, regulating the DC bus current value voltage, and continuing to execute step S1 until the DC bus current value voltage is equal to the DC bus final value voltage.

[0024] Optionally, the slow start operation of the voltage slow start unit is:

[0025] Among them, U dc_0 is the initial voltage of the voltage slow-start unit, U Dref is the command voltage of the voltage control unit, N is the number of slow-start cycles of the slow-start operation, n i is the slow start count value, N is a natural number greater than 0, and i is a natural number.

[0026] Optionally, the voltage control unit includes a voltage feedback control loop and a voltage feedforward control loop; the voltage feedback control loop obtains a phase shift angle corresponding to a reference current of the DC bus capacitor by performing a first operation and a second operation of the voltage control unit on the voltage control unit instruction voltage and the current value voltage of the DC bus;

[0027] The voltage feedforward control loop performs a third operation of the voltage control unit on the load reference current, releases the coupling relationship between the feedforward loop and the transmission power, and obtains the phase shift angle corresponding to the load current reference value. The voltage control unit calculates the phase shift angle corresponding to the DC bus capacitor reference current and the phase shift angle corresponding to the load current reference value to finally obtain the phase shift angle control signal of the voltage control unit.

[0028] Optionally, the first operation of the voltage control unit is: Among them, G PI_DAB (S) is a linear PI regulator, K p_DAB is the proportional coefficient of the PI regulator, T r_DAB is the integral time constant of the PI regulator, and S is the parameter of the S transformation;

[0029] The second operation of the voltage control unit is: Among them, d DAB_cref is the phase shift angle, i cref is the DC bus capacitor reference current;

[0030] The third operation of the voltage control unit is: Among them, d DAB_2cref is the load current reference value i 2ref The corresponding phase shift angle, i 2ref is the load current reference value i 2ref , k* is the theoretical value of the input proportional constant k, k = (nv1) / (2f DAB L DAB ), v1 is the input voltage, n is the change ratio of the high-frequency isolation transformer, f DAB is the DAB switching signal frequency, L DAB It is a DAB phase shift inductor.

[0031] Optionally, the step of the current control unit performing calculation to obtain a phase shift angle control signal of the current control unit includes:

[0032] The step of the current control unit performing calculation to obtain the phase shift angle control signal of the current control unit comprises:

[0033] Acquire the load power and filter it through the filtering module, and then subtract it from the DC bus command power to obtain a power error signal;

[0034] The power error signal is calculated through a current feedback control loop to obtain a transmission power command value;

[0035] The transmission power command value is converted into a phase shift angle control signal of the current control unit under the decoupling effect of the fourth operation of the current control unit.

[0036] Optionally, the fourth operation of the current control unit is:

[0037]

[0038] Among them, d DAB is the transmission power command value P DAB * The corresponding phase shift angle control signal d DAB、f DAB is the DAB switch signal frequency, L DAB DAB phase shift inductor, P* DAB is the transmission power command value, n is the change ratio of the high-frequency isolation transformer, v1 is the input voltage, U DC is the current value voltage of the DC bus.

[0039] An embodiment of the present invention further provides a control method for a DC port control circuit, comprising:

[0040] The mode switching unit outputs an acquisition mode switching signal. When the mode switching signal is a voltage control unit working signal, a path is formed between the voltage slow start unit, the voltage control unit and the mode switching unit. The voltage slow start unit acquires the current value voltage of the DC bus and the final value voltage of the DC bus to perform calculations to obtain a voltage control unit command voltage, and outputs the voltage control unit command voltage to the voltage control unit.

[0041] The voltage slow-start unit obtains the current value voltage of the DC bus and the final value voltage of the DC bus, performs several slow-start operations, obtains the voltage control unit command voltage, and outputs the voltage control unit command voltage to the voltage control unit;

[0042] The voltage control unit obtains the voltage control unit command voltage, the DC bus current value voltage, and the load reference current to perform calculations to obtain a phase shift angle control signal of the voltage control unit, and outputs the phase shift angle control signal of the voltage control unit to the mode switching unit;

[0043] When the mode switching signal is a working signal of the current control unit, a path is formed between the current control unit and the mode switching unit, the current control unit obtains the DC bus command power, the DC bus current value voltage, and the load reference current to perform calculations to obtain a phase shift angle control signal of the current control unit, and outputs the phase shift angle control signal of the current control unit to the mode switching unit;

[0044] The mode switching unit obtains a mode switching signal, and accordingly, calculates the obtained phase shift angle control signal of the voltage control unit and the phase shift angle control signal of the current control unit to generate a corresponding PWM signal and outputs it to the DC port, thereby regulating the initial value voltage of the DC port to the final value voltage of the DC bus.

[0045] An embodiment of the present invention further provides a DC port controller, comprising the above-mentioned DC port control circuit.

[0046] An embodiment of the present invention further provides an energy router, comprising an energy router central processor, a DC port and the above-mentioned DC port controller;

[0047] The energy router central processor is connected to the DC port local controller, and the DC port local controller is connected to the DC port.

[0048] In summary, the advantages and beneficial effects of the present invention are:

[0049] The present invention provides a DC port control circuit, a local controller, a control method and an energy router, wherein the DC port control circuit comprises: a mode switching unit, a voltage slow start unit, a voltage control unit and a current control unit. The DC port control circuit regulates the current value voltage of the DC bus to the final value voltage of the DC bus, wherein the voltage control unit tracks the voltage control unit instruction voltage output by the voltage slow start unit, and the voltage control unit instruction voltage is further stabilized by the voltage control unit to obtain the phase shift angle control signal of the voltage control unit; the DC bus instruction power is tracked by the current control unit, and the DC bus instruction power is processed and calculated to obtain the phase shift angle control signal of the current control unit, and the phase shift angle control signal of the voltage control unit and the phase shift angle control signal of the current control unit are obtained by the mode switching unit, and the corresponding PWM signal is calculated and generated and output to the DC port, thereby regulating the initial value voltage of the DC port to the final value voltage of the DC bus.

[0050] At the same time, when the power grid fails and the energy storage SOC is about to reach the upper limit value, the DC bus command power gradually drops to 0. At this time, the mode switching signal obtained by the mode switching unit is a voltage control unit working signal, so that the voltage slow start unit and the voltage control unit work, and the DC port control circuit switches to the voltage control mode, and through subsequent regulation of the DC port, the voltage on the DC port side is quickly regulated. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1~Figure 2 A schematic diagram of a DC port control circuit provided by the present invention; Figure 3 A schematic diagram of a voltage slow-start unit of a DC port control circuit provided by the present invention performing a slow-start operation; Figure 4 A schematic diagram of a voltage control unit of a DC port control circuit provided by the present invention; Figure 5 A schematic diagram of a current control unit of a DC port control circuit provided by the present invention; Figure 6 A schematic diagram of an energy router provided by the present invention. DETAILED DESCRIPTION

[0056] In order to facilitate understanding by those skilled in the art, the present invention will be further described in detail below with reference to specific embodiments.

[0057] The present invention provides a DC port control circuit, please refer to Figure 1 ,include:

[0058] A voltage slow start unit 10, a voltage control unit 20, a current control unit 30, a mode switching unit 40, and an upper communication control unit 50;

[0059] The upper communication control unit 50 is connected to the voltage slow start unit 10, the mode switching unit 40, and the current control unit 30. The voltage slow start unit 10 is connected to the voltage control unit 20. The voltage control unit 20 and the current control unit 30 are both connected to the mode switching unit 40.

[0060] The upper communication control unit 50 obtains the DC bus final value voltage U DC_ref And output to the voltage slow start unit 10 to obtain the DC bus command power P Dref And output to the current control unit 30 to obtain the mode switching signal S M and output to the mode switching unit 40;

[0061] The mode switching unit 40 obtains a mode switching signal S M , when the mode switching signal S M When the voltage control unit working signal is a voltage control unit, a path is formed between the voltage slow start unit 10, the voltage control unit 20 and the mode switching unit 40, and the voltage slow start unit 10 obtains the current value voltage U of the DC bus. DC , DC bus final voltage U DC_ref Calculate and obtain the voltage control unit command voltage U Dref , the voltage control unit commands the voltage U Dref Output to the voltage control unit 20;

[0062] The voltage control unit 20 obtains the voltage control unit command voltage U Dref , the current value voltage U of the DC bus DC , load reference current i 2ref Calculate and obtain the phase shift angle control signal d of the voltage control unit DAB_U , the phase shift angle control signal d of the voltage control unit DAB_U Output to the mode switching unit 40;

[0063] When the mode switching signal S M When the current control unit working signal is a current control unit working signal, a path is formed between the current control unit 30 and the mode switching unit 40, and the current control unit 30 obtains the DC bus command power P Dref , the current value voltage U of the DC bus DC , load reference current i 2ref Calculate and obtain the phase shift angle control signal d of the current control unit DAB_I , the phase shift angle control signal d of the current control unit DAB_I Output to the mode switching unit 40;

[0064] The mode switching unit 40 obtains a mode switching signal S M , accordingly, the phase shift angle control signal d of the voltage control unit is obtained DAB_U , the phase shift angle control signal d of the current control unit DAB_I The corresponding PWM signal is generated and output to the DC port, and the initial voltage of the DC port is adjusted to the final voltage of the DC bus.

[0065] Specifically, in the embodiment of the present invention, the upper communication control unit 50 is the link for information exchange between the DC port control circuit and the energy router central controller.

[0066] In the embodiment of the present invention, the upper communication control unit 50 obtains the DC bus final value voltage U through the energy router central processor DC_ref , the DC bus command power P Dref , mode switching signal S M .

[0067] In the embodiment of the present invention, the upper communication control unit 50 outputs the local state information of the DC port to the central processor of the energy router, wherein the local state information of the DC port includes: the current value voltage U DC , the phase shift angle control signal d of the voltage control unit DAB_U , the phase shift angle control signal d of the current control unit DAB_I , the PWM signal or other local status information.

[0068] In other embodiments, the DC port control circuit does not have the upper communication control unit, and the voltage slow start unit directly obtains the DC bus final value voltage U through the energy router central controller. DC_ref The current control unit directly obtains the DC bus command power P through the energy router central controller DrefThe mode switching unit directly obtains the mode switching signal S through the energy router central controller M .

[0069] In the embodiment of the present invention, the voltage slow start unit 10 generates the voltage control unit command voltage U by a ramp linear slow start method. Dref , using the voltage control unit to instruct the voltage U Dref And subsequent regulation to achieve the DC bus voltage stabilization to the DC bus final value voltage U DC_ref , to avoid the DC port switching due to the DC bus current value voltage U DC Not equal to the DC bus final voltage U DC_ref , resulting in current impact on the DC bus.

[0070] In the embodiments of the present invention, please refer to Figure 3 The voltage slow start unit 20 performs the slow start operation including:

[0071] Step S1, determining the mode switching signal S M Is it a voltage control unit working signal? If the mode switching signal S M is not a voltage control unit working signal, then execute step S2; if the mode switching signal S M If it is a voltage control unit working signal, execute step S3.

[0072] In the embodiment of the present invention, when the power grid fails and the energy storage SOC (State of Charge, the ratio of the current power of the energy storage battery to the full power) is about to reach the upper limit, the DC bus command power P Dref Gradually decreases to 0. At this time, the mode switching signal S obtained by the mode switching unit 40 M The voltage control unit working signal, the mode switching unit switch K is connected to 1, that is: S M =1, at this time, the voltage slow start unit 10 and the voltage control unit 20 work, and the DC port control circuit switches to the voltage control mode, so as to quickly adjust the voltage on the DC port side; the mode switching signal S obtained by the mode switching unit 40 M The current control unit working signal, the mode switching unit switch K is connected to 0, that is: S M ≠1, at this time, the current control unit works, the DC port control circuit switches to the current control mode, and the voltage on the DC port side is regulated by the current control mode.

[0073] Step S2: the voltage slow-start unit 10 does not work.

[0074] In the embodiment of the present invention, the mode switching signal S M ≠1, at this time, the current control unit 30 works in the current control mode and does not perform the slow start operation.

[0075] Step S3, determining the current value of the DC bus voltage U DC Is it equal to the DC bus final voltage U DC_ref , if the current value of the DC bus voltage U DC Equal to the DC bus final voltage U DC_ref , ramp command F ramp is set to be not equal to 0, and step S4 is executed; if the current value voltage U DC Not equal to the DC bus final voltage U DC_ref , ramp command F ramp Set to 0 and execute step S5.

[0076] In the embodiment of the present invention, if the current value voltage U DC Equal to the DC bus final voltage U DC_ref , set the ramp command F ramp is not 0, that is, the ramp instruction F ramp is 1; if the current value voltage U DC Not equal to the DC bus final voltage U DC_ref , set the ramp command F ramp is 0.

[0077] In the embodiment of the present invention, when the ramp command F ramp When the voltage slow start unit 10 performs a slow start operation, and obtains several corresponding voltage control unit command voltages U through several slow start operations in a ramp linear slow start manner. Dref , and then through subsequent regulation, the DC bus current value voltage U DC Regulated to the DC bus final voltage U DC_ref .

[0078] Step S4: the DC bus current voltage U DC Equal to the DC bus final voltage U DC_ref , set the ramp command F ramp is 1, the output voltage control unit command voltage U Dref , regulate the current value voltage U of the DC bus DC , continue to step S1.

[0079] Step S5, determining whether the voltage slow start unit 10 has completed initialization, if the voltage slow start unit 10 has not been initialized, setting the initialization instruction F iniis 0, execute step 6; if the voltage slow start unit 10 completes initialization, the initialization instruction F init If it is not 0, go to step 7.

[0080] In the embodiment of the present invention, when the initialization instruction F init When it is not 0, set the initialization instruction F init is 1, at this time, the voltage slow start unit 10 completes initialization.

[0081] In the embodiment of the present invention, if the voltage slow-start unit 10 has completed initialization, the voltage slow-start unit 10 directly performs subsequent slow-start operations for several times.

[0082] Step S6, initializing the voltage slow start unit 10, wherein:

[0083] Set the DC bus current value voltage U DC As the initial voltage U of the voltage slow start unit dc_0 , the DC bus final voltage U DC_ref The final value of the slow start operation of the voltage slow start unit 10 is set to N, and the slow start count value is set to n. i , the first slow start count value n1 = 0, set the initialization instruction F init If it is 1, go to step 7.

[0084] Step S7, execute n i +1, go to step S8.

[0085] In the embodiment of the present invention, by n i +1 is used to count the number of buffered operation cycles.

[0086] Step S8, determine n i +1 is greater than or equal to the number of slow-start cycles N of the slow-start operation. If the n i +1 is greater than or equal to the number of slow-start cycles N of the slow-start operation, then execute step S4; if the n i +1 is less than the number N of slow-start cycles of the slow-start operation, then step S9 is executed.

[0087] In the embodiment of the present invention, when n i +1 is greater than or equal to the slow-start cycle number N of the slow-start operation, the voltage slow-start unit 10 completes the preset N slow-start operations, wherein N is the preset slow-start cycle number of the slow-start operation, N is a natural number greater than 0, and i is a natural number.

[0088] Step S9, obtaining the voltage control unit command voltage U by slow start operation Dref , regulate the current value voltage U of the DC bus DC, continue to execute step S1 until the current value voltage U DC Equal to the DC bus final voltage U DC_ref .

[0089] In an embodiment of the present invention, the slow start operation of the voltage slow start unit is:

[0090] Among them, U dc_0 is the initial voltage of the voltage slow-start unit, U Dref is the command voltage of the voltage control unit, N is the number of slow-start cycles of the slow-start operation, n i is the slow start count value, N is a natural number greater than 0, and i is a natural number.

[0091] In the embodiment of the present invention, the voltage control unit command voltage U is obtained through the slow start operation. Dref , tracking the voltage control unit command voltage U Dref , regulate the current value voltage U of the DC bus DC Gradually stabilize the DC bus terminal voltage U DC_ref .

[0092] In the embodiment of the present invention, the voltage control unit 20 tracks the voltage control unit command voltage U output by the voltage slow start unit 10. Dref , and the voltage control unit commands the voltage U Dref The voltage control unit calculates the voltage U Dref After further voltage stabilization, the phase shift angle control signal d of the voltage control unit 20 is obtained. DAB_U .

[0093] In the embodiments of the present invention, please refer to Figure 4 , the voltage control unit 20 includes: a voltage feedback control loop 21 and a voltage feedforward control loop 22;

[0094] The voltage feedback control loop 21 is used to instruct the voltage control unit to output a voltage U Dref , the current value voltage U of the DC bus DC The DC bus capacitor reference current i is obtained by the first operation of the voltage control unit 20 and the second operation of the voltage control unit 20. cref The corresponding phase shift angle d DAB_cref ;

[0095] The voltage feedforward control loop 22 is used to control the load reference current i 2ref The third operation of the voltage control unit 20 is performed to release the coupling relationship between the feedforward loop and the transmission power, and obtain the load current reference value i 2ref The corresponding phase shift angle dDAB_2ref ;

[0096] The voltage control unit 20 controls the DC bus capacitor reference current i cref The corresponding phase shift angle d DAB_cref and the load current reference value i 2ref The corresponding phase shift angle d DAB_2ref The calculation is performed to finally obtain the phase shift angle control signal d of the voltage control unit. DAB_U .

[0097] In the embodiment of the present invention, the voltage feedback control loop 21 instructs the voltage control unit to generate a voltage U Dref , the current value voltage U of the DC bus DC The DC bus capacitor reference current i is obtained by the first operation of the voltage control unit 20 and the second operation of the voltage control unit 20. cref The corresponding phase shift angle d DAB_cref The steps include:

[0098] The voltage control unit commands the voltage U Dref The DC bus current value voltage U DC The difference is input to the linear PI regulator (G PI_DAB (S));

[0099] The linear PI regulator (G PI_DAB (S)) performs the first operation of the voltage control unit 20 to obtain the DC bus capacitor reference current i cref ;

[0100] According to the DC bus capacitor reference current i cref The second operation of the voltage control unit 20 is performed to obtain the DC bus capacitor reference current i cref The corresponding phase shift angle d DAB_cref .

[0101] Since the DC bus capacitor current i c With the DC bus current value voltage U DC The first-order corresponding relationship presented is used to obtain the current value voltage U of the DC bus. DC , the voltage control unit commands the voltage U Dref The DC bus current value voltage U DC The difference is input to the linear PI regulator (G PI_DAB (S)), the linear PI regulator (G PI_DAB (S)) obtains the DC bus capacitor reference current i through the internal integration link cref , that is, by setting the voltage control unit to command voltage U Dref The DC bus current value voltage UDC The difference between the voltage and the reference current i is used as the input value of the first operation of the voltage control unit 20. By operation, the DC bus capacitor reference current i cref , where the DC bus capacitor current i c With the DC bus current value voltage U DC The first-order correspondence presented is: U DC is the current voltage of the DC bus, C DAB is the DC bus capacitance, i c is the DC bus capacitor current.

[0102] In the embodiment of the present invention, the DC bus capacitor current i c For: i c =k*v 1ref d DAB_c (1-|d DAB_c |), k*=(n*v 1ref ) / (2f DAB L DAB *), n* is the theoretical value of the change ratio of the high-frequency isolation transformer, v 1ref represents the steady-state value of the input voltage, f DAB is the DAB (DC) switching signal frequency, L DAB * is the theoretical value of DAB phase shift inductance, d DAB_c is the DC bus capacitor current phase shift angle.

[0103] In the embodiment of the present invention, the linear PI regulator (G PI_DAB The first operation of the voltage control unit 20 performed by (S) is:

[0104] Among them, G PI_DAB (S) is a linear PI regulator, K p_DAB is the proportional coefficient of the PI regulator, T r_DAB is the integral time constant of the PI regulator, and S is the S transformation parameter.

[0105] In the embodiment of the present invention, the second operation of the voltage control unit 20 is: Among them, d DAB_cref is the DC bus capacitor reference current i cref The corresponding phase shift angle, i cref is the DC bus capacitor reference current, k* is the theoretical value of the input proportional constant k, k=(nv1) / (2f DAB L DAB ), v1 is the input voltage, n is the change ratio of the high-frequency isolation transformer, f DAB is the DAB switching signal frequency, L DABis the DAB phase-shift inductor, and the DC bus capacitor reference current i is realized through the second operation of the voltage control unit 20. cref To the DC bus capacitor reference current i cref The corresponding phase shift angle d DAB_cref The nonlinear one-to-one correspondence of .

[0106] In the embodiment of the present invention, the voltage feedforward control loop 22 controls the load reference current i 2ref Perform the third operation of the voltage control unit to release the coupling relationship between the feedforward loop and the transmission power, and obtain the load current reference value i 2ref The corresponding phase shift angle d DAB_2ref .

[0107] In an embodiment of the present invention, the load current reference value i is obtained. 2ref The corresponding phase shift angle d DAB_2ref The third operation of the voltage control unit 20 is: Among them, d DAB_2cref is the load current reference value i 2ref The corresponding phase shift angle, i 2ref is the load current reference value i 2ref , k* is the theoretical value of the input proportional constant k, k = (nv1) / (2f DAB L DAB ), v1 is the input voltage, n is the change ratio of the high-frequency isolation transformer, f DAB is the DAB switching signal frequency, L DAB It is a DAB phase shift inductor.

[0108] In the embodiment of the present invention, the voltage control unit 20 controls the DC bus capacitor reference current i cref The corresponding phase shift angle d DAB_cref and the load current reference value i 2ref The corresponding phase shift angle d DAB_2ref After addition, the phase shift angle control signal d of the voltage control unit is finally obtained. DAB_U , the phase shift angle control signal d of the voltage control unit DAB_U The output is sent to SPS modulation to realize the regulation of the DC port.

[0109] In the embodiment of the present invention, the mode switching signal S obtained by the mode switching unit 40 M When it is the working signal of the current control unit, the mode switching unit switch K is connected to 0. At this time, the current control unit 30 works, and the DC port control circuit switches to the current control mode, and the voltage on the DC port side is regulated by the current control mode.

[0110] In the embodiment of the present invention, please refer to Figure 5 The current control unit includes: a current feedback control loop 31 and a filter module 32; the current feedback control loop 31 and the filter module 32 are used to track the DC bus command power P Dref , and the DC bus command power P Dref Processing and calculation are performed to obtain the phase shift angle control signal d of the current control unit. DAB_I .

[0111] In the embodiment of the present invention, the current control unit 30 performs calculation to obtain the phase shift angle control signal d of the current control unit. DAB_I The steps include:

[0112] Get load power T ADS After being filtered by the filtering module 32, it is combined with the DC bus command power P Dref The power error signal Δp is obtained by subtracting DAB ;

[0113] The power error signal Δp DAB The transmission power command value P is obtained by calculating the current feedback control loop 31. DAB *;

[0114] The transmission power command value P DAB * Under the decoupling effect of the fourth operation of the current control unit 30, the transmission power command value P DAB *Converted into the phase shift angle control signal d of the current control unit DAB_I .

[0115] In the embodiment of the present invention, the load power T ADS T ADS =U DC *i 2ref , where U DC is the current voltage of the DC bus, i 2ref is the load reference current i 2ref ;

[0116] The load power T ADS After filtering by the filtering module 32,

[0117] In the embodiment of the present invention, the current feedback control loop 31 is based on a PI regulator (G PI_DAB (S)) of power feedback control.

[0118] In the embodiment of the present invention, the fourth operation of the current control unit is:

[0119]

[0120] Among them, d DAB_I is the phase shift angle control signal of the current control unit, f DAB is the DAB switch signal frequency, L DAB For DAB phase shift inductor, P* DAB is the transmission power command value, n is the change ratio of the high-frequency isolation transformer, v1 is the input voltage, U DC is the current value voltage of the DC bus.

[0121] In the embodiment of the present invention, when the power grid fails and the energy storage SOC is about to reach the upper limit value, the DC bus command power P Dref Gradually decreases to 0. At this time, the mode switching signal S obtained by the mode switching unit 40 M is the working signal of the voltage control unit, the mode switching unit switch is changed from connection 0 to connection 1, that is, the voltage slow start unit 10 and the voltage control unit 20 work, and the DC port control circuit switches to the voltage control mode, so as to quickly regulate the voltage on the DC port side.

[0122] In the embodiment of the present invention, the mode switching unit obtains the mode switching signal S M , accordingly, the phase shift angle control signal d of the voltage control unit is obtained DAB_U Or the phase shift angle control signal d of the current control unit DAB_I The operation is performed to generate a corresponding PWM signal and output it to the DC port, and the initial voltage of the DC port is adjusted to the final voltage of the DC bus. The mode switching signal S M Including voltage control unit working signal and voltage control unit working signal.

[0123] In the embodiment of the present invention, the DC port tracks the DC bus command power P through the current control unit when connected to the grid. Dref When the energy router is isolated and its own energy storage SOC (State of Charge, the ratio of the current power of the energy storage battery to the full power) reaches a predetermined upper limit, the DC bus command power P Dref Gradually decreases to 0, at this time, the mode switching signal S obtained by the mode switching unit M It is a working signal of the voltage control unit, so that a path is formed between the voltage slow start unit 10, the voltage control unit 20 and the mode switching unit 40, that is, the DC port is switched to the voltage control mode, so as to quickly stabilize the voltage on the grid-connected port side.

[0124] In the embodiment of the present invention, when the mode switching unit obtains the mode switching signal S MWhen the voltage control unit working signal is the voltage control unit, the mode switching unit switch K is connected to 1, so that a path is formed between the voltage slow start unit 20, the voltage control unit 20 and the mode switching unit 40; when the mode switching unit 40 obtains the mode switching signal S M When the current control unit is operating, the mode switching unit switch K is connected to 0, so that a path is formed between the current control unit 30 and the mode switching unit 40 .

[0125] In the embodiment of the present invention, the PWM signal gradually adjusts the current voltage U of the DC bus by adjusting the first diode structure Q1 to the eighth diode structure Q8. DC Equal to the DC bus final voltage U DC-ref .

[0126] An embodiment of the present invention further provides a control method for a DC port control circuit, comprising:

[0127] The mode switching unit outputs an acquisition mode switching signal S M , when the mode switching signal S M When the voltage control unit working signal is a voltage control unit working signal, a path is formed between the voltage slow start unit, the voltage control unit and the mode switching unit, and the voltage slow start unit obtains the current value voltage U of the DC bus. DC , DC bus final voltage U DC_ref Calculate and obtain the voltage control unit command voltage U Dref , the voltage control unit commands the voltage U Dref output to the voltage control unit;

[0128] The voltage slow start unit obtains the current value voltage U of the DC bus DC and DC bus final voltage U DC_ref , perform several slow start operations to obtain the voltage control unit command voltage U Dref , and the voltage control unit commands the voltage U Dref output to the voltage control unit;

[0129] The voltage control unit obtains the voltage control unit command voltage U Dref , the current value voltage U of the DC bus DC , load reference current i 2ref Calculate and obtain the phase shift angle control signal d of the voltage control unit DAB_U , the phase shift angle control signal d of the voltage control unit DAB_U output to the mode switching unit;

[0130] When the mode switching signal S MWhen the current control unit working signal is a current control unit working signal, a path is formed between the current control unit and the mode switching unit, and the current control unit obtains the DC bus command power P Dref , the current value voltage U of the DC bus DC , load reference current i 2ref Calculate and obtain the phase shift angle control signal d of the current control unit DAB_I , the phase shift angle control signal d of the current control unit DAB_I output to the mode switching unit;

[0131] The mode switching unit obtains a mode switching signal S M , accordingly, the phase shift angle control signal d of the voltage control unit is obtained DAB_U , the phase shift angle control signal d of the current control unit DAB_I The corresponding PWM signal is generated and output to the DC port, and the initial voltage of the DC port is adjusted to the final voltage of the DC bus.

[0132] An embodiment of the present invention further provides a DC port controller, including: including the above-mentioned DC port control circuit.

[0133] The embodiment of the present invention also provides an energy router, please refer to Figure 5 , comprising: an energy router central processor, a DC port and a DC port controller as described above;

[0134] The energy router central processor is connected to the DC port local controller, and the DC port local controller is connected to the DC port.

[0135] Finally, it is to be noted that any modification or equivalent replacement of part or all of the technical features based on the device structure of the present invention and the technical solution of the described embodiment, which does not deviate from the essence of the corresponding technical solution of the present invention, belongs to the patent scope of the device structure of the present invention and the described implementation scheme.

Claims

1. A DC port control circuit, characterized in that: include: Mode switching unit, voltage slow start unit, voltage control unit, current control unit; The voltage slow start unit is connected to the voltage control unit, and the voltage control unit and the current control unit are both connected to the mode switching unit; The mode switching unit obtains a mode switching signal. When the mode switching signal is a voltage control unit working signal, a path is formed between the voltage slow start unit, the voltage control unit and the mode switching unit. The voltage slow start unit obtains the current value voltage of the DC bus and the final value voltage of the DC bus, performs several slow start operations, obtains the voltage control unit command voltage, and outputs the voltage control unit command voltage to the voltage control unit. The voltage control unit obtains the voltage control unit command voltage, the DC bus current value voltage, and the load reference current to perform calculations to obtain a phase shift angle control signal of the voltage control unit, and outputs the phase shift angle control signal of the voltage control unit to the mode switching unit; When the mode switching signal is a working signal of the current control unit, a path is formed between the current control unit and the mode switching unit, the current control unit obtains the DC bus command power, the DC bus current value voltage, and the load reference current to perform calculations to obtain a phase shift angle control signal of the current control unit, and outputs the phase shift angle control signal of the current control unit to the mode switching unit; The mode switching unit obtains a mode switching signal, and accordingly, calculates the obtained phase shift angle control signal of the voltage control unit and the phase shift angle control signal of the current control unit to generate a corresponding PWM signal and outputs it to the DC port, thereby regulating the initial value voltage of the DC port to the final value voltage of the DC bus.

2. A DC port control circuit as claimed in claim 1, characterized in that: The step of performing a slow start operation by the voltage slow start unit comprises: Step S1, determining whether the mode switching signal is a voltage control unit working signal, if the mode switching signal is not a voltage control unit working signal, executing step S2; if the mode switching signal is a voltage control unit working signal, executing step S3; Step S2, the voltage slow start unit does not work; Step S3, judging whether the current value voltage of the DC bus is equal to the final value voltage of the DC bus; if the current value voltage of the DC bus is equal to the final value voltage of the DC bus, the ramp instruction is set to be not equal to 0, and step S4 is executed; if the current value voltage of the DC bus is not equal to the final value voltage of the DC bus, the ramp instruction is set to 0, and step S5 is executed; Step S4, the DC bus current voltage is equal to the DC bus final voltage, the ramp instruction is set to 1, the output voltage control unit instruction voltage is output, the DC bus current voltage is adjusted, and step S1 is continued; Step S5, determining whether the voltage slow start unit 10 has completed initialization. If the voltage slow start unit 10 has not been initialized, setting the initialization instruction to 0, and executing step 6; if the voltage slow start unit 10 has completed initialization and the initialization instruction is not 0, executing step 7; Step S6, initializing the voltage slow start unit, wherein: The current voltage of the DC bus is set as the initial voltage of the voltage slow start unit, the final voltage of the DC bus is the final value of the slow start operation of the voltage slow start unit, the slow start cycle number of the slow start operation is set to N, and the slow start count value is set to n i , the first slow start count value n1=0, set the initialization instruction to 1, and execute step 7; Step S7, execute n i +1, go to step S8; Step S8, determine n i +1 is greater than or equal to the number of slow-start cycles N of the slow-start operation. If the n i +1 is greater than or equal to the number of slow-start cycles N of the slow-start operation, then execute step S4; if the n i +1 is less than the number of slow-start cycles N of the slow-start operation, then execute step S9; Step S9, obtaining the voltage control unit command voltage through a slow-start operation, adjusting the DC bus current value voltage, and continuing to execute step S1 until the DC bus current value voltage is equal to the DC bus final value voltage.

3. A DC port control circuit as claimed in claim 1, characterized in that: The slow start operation of the voltage slow start unit is: Among them, U dc_0 is the initial voltage of the voltage slow-start unit, U Dref is the command voltage of the voltage control unit, N is the number of slow-start cycles of the slow-start operation, n i is the slow start count value, N is a natural number greater than 0, and i is a natural number.

4. A DC port control circuit as claimed in claim 1, characterized in that: The voltage control unit includes a voltage feedback control loop and a voltage feedforward control loop; the voltage feedback control loop obtains the phase shift angle corresponding to the DC bus capacitor reference current by performing a first operation and a second operation of the voltage control unit on the voltage control unit command voltage and the DC bus current value voltage; The voltage feedforward control loop performs a third operation of the voltage control unit on the load reference current, releases the coupling relationship between the feedforward loop and the transmission power, and obtains the phase shift angle corresponding to the load current reference value. The voltage control unit calculates the phase shift angle corresponding to the DC bus capacitor reference current and the phase shift angle corresponding to the load current reference value to finally obtain the phase shift angle control signal of the voltage control unit.

5. A DC port control circuit as claimed in claim 4, characterized in that: The first operation of the voltage control unit is: Among them, G PI_DAB (S) is a linear PI regulator, K p_DAB is the proportional coefficient of the PI regulator, T r_DAB is the integral time constant of the PI regulator, and S is the parameter of the S transformation; The second operation of the voltage control unit is: Among them, d DAB_cref is the phase shift angle, i cref is the DC bus capacitor reference current; The third operation of the voltage control unit is: Among them, d DAB_2cref is the load current reference value i 2ref The corresponding phase shift angle, i 2ref is the load current reference value i 2ref , k* is the theoretical value of the input proportional constant k, k = (nv1) / (2f DAB L DAB ), v1 is the input voltage, n is the change ratio of the high-frequency isolation transformer, f DAB is the DAB switching signal frequency, L DAB It is a DAB phase shift inductor.

6. A DC port control circuit as claimed in claim 1, characterized in that: The step of the current control unit performing calculation to obtain the phase shift angle control signal of the current control unit comprises: The step of the current control unit performing calculation to obtain the phase shift angle control signal of the current control unit comprises: Acquire the load power and filter it through the filtering module, and then subtract it from the DC bus command power to obtain a power error signal; The power error signal is calculated through a current feedback control loop to obtain a transmission power command value; The transmission power command value is converted into a phase shift angle control signal of the current control unit under the decoupling effect of the fourth operation of the current control unit.

7. A DC port control circuit as claimed in claim 6, characterized in that: The fourth operation of the current control unit is: Among them, d DAB is the transmission power command value P DAB * The corresponding phase shift angle control signal d DAB 、f DAB is the DAB switch signal frequency, L DAB DAB phase shift inductor, P* DAB is the transmission power command value, n is the change ratio of the high-frequency isolation transformer, v1 is the input voltage, U DC is the current value voltage of the DC bus.

8. A control method for a DC port control circuit, characterized in that: include: The mode switching unit outputs an acquisition mode switching signal. When the mode switching signal is a voltage control unit working signal, a path is formed between the voltage slow start unit, the voltage control unit and the mode switching unit. The voltage slow start unit acquires the current value voltage of the DC bus and the final value voltage of the DC bus to perform calculations to obtain a voltage control unit command voltage, and outputs the voltage control unit command voltage to the voltage control unit. The voltage slow-start unit obtains the current value voltage of the DC bus and the final value voltage of the DC bus, performs several slow-start operations, obtains the voltage control unit command voltage, and outputs the voltage control unit command voltage to the voltage control unit; The voltage control unit obtains the voltage control unit command voltage, the DC bus current value voltage, and the load reference current to perform calculations to obtain a phase shift angle control signal of the voltage control unit, and outputs the phase shift angle control signal of the voltage control unit to the mode switching unit; When the mode switching signal is a working signal of the current control unit, a path is formed between the current control unit and the mode switching unit, the current control unit obtains the DC bus command power, the DC bus current value voltage, and the load reference current to perform calculations to obtain a phase shift angle control signal of the current control unit, and outputs the phase shift angle control signal of the current control unit to the mode switching unit; The mode switching unit obtains a mode switching signal, and accordingly, calculates the obtained phase shift angle control signal of the voltage control unit and the phase shift angle control signal of the current control unit to generate a corresponding PWM signal and outputs it to the DC port, thereby regulating the initial value voltage of the DC port to the final value voltage of the DC bus.

9. A DC port controller, characterized in that: It comprises a DC port control circuit as claimed in any one of claims 1 to 7.

10. An energy router, characterized in that: It comprises an energy router central processor, a DC port and a DC port controller as claimed in claim 9; The energy router central processor is connected to the DC port local controller, and the DC port local controller is connected to the DC port.

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