Power distribution network electric energy treatment circuit and control method thereof

Abstract

The invention discloses an electric energy management circuit for a power distribution network. The electric energy management circuit comprises a transformer, a first full-bridge circuit, a second full-bridge circuit and a capacitor, the second full-bridge circuit is used for transmitting a voltage fluctuation signal to the first full-bridge circuit through the transformer when the voltage of the power distribution network fluctuates; the first full-bridge circuit is used for generating output voltage and loading the output voltage to the two ends of the capacitor so as to stabilize load voltage signals of the output end of the power distribution network electric energy management circuit. The invention further discloses a control method of the power distribution network electric energy management circuit. The power distribution network electric energy management circuit is arranged at the output end of the power distribution network, and the power distribution network electric energy management circuit is controlled by adopting a corresponding control algorithm; therefore, the power management of the power distribution network can be realized, the stability of the power supply voltage of the power distribution network is ensured, the power supply quality of the power distribution network is improved, the corresponding management process is completed only by adopting one circuit, the reliability is higher, and the method is simpler and more efficient.

Description

Technical Field

[0001] The present invention belongs to the field of electrical automation, and in particular relates to a power management circuit for a distribution network and a control method thereof. Background Art

[0002] With the development of economy and technology and the improvement of people's living standards, electricity has become an indispensable secondary energy source in people's production and life, bringing endless convenience to people's production and life. Therefore, ensuring the stable and reliable supply of electricity has become one of the most important tasks of the power system.

[0003] The power quality of the distribution network directly affects the reliability and safety of the power supply in the distribution network. Low-quality power supply will lead to increased line losses, equipment failures, power outages and other problems, and affect the production and life of users. In some power supply areas, the transformer outlet voltage is in a low voltage state due to seasonal and intermittent fluctuations in load, and the impact load exacerbates the voltage fluctuation; when there is a large load at the end of the line, it will also cause the problem of low terminal power supply voltage. Especially in mountainous and remote areas, some substations have a long power supply radius, poor power quality at the end of the power supply, and low power supply reliability, so that the power supply voltage is often lower than the standard voltage (220V). Too low voltage will cause the user's electrical equipment to fail to work properly.

[0004] In view of the above situation, the current power system uses a unified power quality controller (UPQC) to manage low voltage problems. At present, the common UPQC architecture diagram is as follows Figure 1 As shown: The UPQC device first connects a rectifier in parallel at the grid end to generate a DC voltage, and then converts the DC voltage into AC through an inverter. This AC is added to the grid through a coupling transformer connected in series to the grid, so that the load side voltage is superimposed on the grid voltage by an AC voltage generated by the inverter, thereby adjusting the grid voltage. When the grid voltage is too low, the UPQC can be used to add a voltage in phase with the grid voltage to achieve voltage boost, so that the load voltage returns to the standard voltage (220V).

[0005] However, the UPQC architecture and control scheme currently used in the power system requires two sets of links, namely rectification and inversion, and requires a series coupling transformer in the power grid. This type of scheme has a relatively complex circuit structure and control scheme, low efficiency, and high cost. Summary of the invention

[0006] One of the purposes of the present invention is to provide a power distribution network power management circuit which is highly reliable, simple and efficient.

[0007] A second object of the present invention is to provide a control method for the power management circuit of the distribution network.

[0008] The power distribution network power management circuit provided by the present invention comprises a transformer, a first full-bridge circuit, a second full-bridge circuit and a capacitor; the primary winding of the transformer is connected to the output end of the second full-bridge circuit, the input end of the second full-bridge circuit is connected to the distribution network and obtains the distribution network voltage; the secondary winding of the transformer is connected to the input end of the first full-bridge circuit, and the output end of the first full-bridge circuit is connected to the two ends of the capacitor; the positive electrode of the capacitor is connected to the positive electrode of the distribution network, and the negative electrode of the capacitor and the negative electrode of the distribution network are the output ends of the power distribution network power management circuit for external power supply; the second full-bridge circuit is used to transmit the voltage fluctuation signal to the first full-bridge circuit through the transformer when the distribution network voltage fluctuates; the first full-bridge circuit is used to generate an output voltage and load it on both ends of the capacitor to ensure the stability of the voltage signal at the output end of the power distribution network power management circuit.

[0009] The transformer, the first full-bridge circuit, the second full-bridge circuit and the capacitor of the power distribution network power management circuit are specifically connected as follows:

[0010] The first full-bridge circuit includes a fifth switch tube, a sixth switch tube, a seventh switch tube, an eighth switch tube, a third capacitor and a fourth capacitor; one end of the action end of the fifth switch tube is connected to the other end of the action end of the sixth switch tube, one end of the action end of the seventh switch tube is connected to the other end of the action end of the eighth switch tube, the other end of the action end of the fifth switch tube is connected to the other end of the action end of the seventh switch tube, and one end of the action end of the sixth switch tube is connected to one end of the action end of the eighth switch tube; the other end of the third capacitor is connected to the other end of the action end of the fifth switch tube, one end of the third capacitor is connected to the other end of the fourth capacitor, and one end of the fourth capacitor is connected to one end of the action end of the sixth switch tube; the secondary winding of the transformer is connected between one end of the action end of the fifth switch tube and one end of the third capacitor;

[0011] The second full-bridge circuit includes a first switch tube, a second switch tube, a third switch tube, a fourth switch tube, a first capacitor and a second capacitor; one end of the action end of the first switch tube is connected to the other end of the action end of the second switch tube, one end of the action end of the third switch tube is connected to the other end of the action end of the fourth switch tube, the other end of the action end of the first switch tube is connected to the other end of the action end of the third switch tube, and one end of the action end of the second switch tube is connected to one end of the action end of the fourth switch tube; the other end of the first capacitor is connected to the other end of the action end of the first switch tube, one end of the first capacitor is connected to the other end of the second capacitor, and one end of the second capacitor is connected to one end of the action end of the second switch tube; the primary winding of the transformer is connected between one end of the action end of the first switch tube and one end of the first capacitor;

[0012] One end of the action end of the fifth switch tube is connected to the negative electrode of the capacitor through the first filter inductor connected in series; one end of the action end of the seventh switch tube is directly connected to one end of the action end of the first switch tube; one end of the action end of the seventh switch tube is also directly connected to the positive electrode of the capacitor; one end of the action end of the third switch tube is connected to the negative electrode of the distribution network through the second filter inductor connected in series; the positive electrode of the distribution network is connected to the positive electrode of the capacitor;

[0013] The negative electrode of the capacitor and the negative electrode of the distribution network are the output ends of the distribution network power management circuit, which are connected to the external load.

[0014] The power distribution network power management circuit described above has the following working process:

[0015] Controlling the primary side voltage of the transformer through the first full-bridge circuit; controlling the capacitor voltage through the second full-bridge circuit;

[0016] When the distribution network voltage is low, low voltage control is carried out:

[0017] The fourth switch tube and the eighth switch tube form a group, and the third switch tube and the seventh switch tube form a group, and they are complementary turned on at a power frequency of 50 Hz;

[0018] The first switch tube and the second switch tube are a group, and the fifth switch tube and the sixth switch tube are a group, which are turned on at a high frequency of 50kHz; there is a phase shift angle θ between the bridge arms where the first switch tube and the second switch tube are located, and the bridge arms where the fifth switch tube and the sixth switch tube are located, and the duty cycle is 50%; in one switching cycle, there are four modes: Mode 1 is 0≤ω s When t≤θ, the first switch tube and the sixth switch tube are closed; Mode 2 is θ≤ω s When t≤π, the first switch tube and the fifth switch tube are closed; mode 3 is π≤ω s When t≤π+θ, the second switch tube and the fifth switch tube are closed; mode 4 is π+θ≤ω s When t≤2π, the second switch tube and the sixth switch tube are closed; ω s is the angular frequency; t is the time;

[0019] When the distribution network voltage is high, high voltage control is carried out:

[0020] The fourth switch tube and the seventh switch tube form a group, and the third switch tube and the eighth switch tube form a group, and they are complementary turned on at a power frequency of 50 Hz;

[0021] The first switch tube and the second switch tube are a group, and the fifth switch tube and the sixth switch tube are a group, which are turned on at a high frequency of 50kHz; there is a phase shift angle θ between the bridge arms where the first switch tube and the second switch tube are located, and the bridge arms where the fifth switch tube and the sixth switch tube are located, and the duty cycle is 50%; in one switching cycle, there are four modes: Mode 1 is 0≤ωs When t≤θ, the second switch tube and the fifth switch tube are closed; Mode 2 is θ≤ω s When t≤π, the second switch tube and the sixth switch tube are closed; Mode 3 is π≤ω s When t≤π+θ, the first switch tube and the sixth switch tube are closed; mode 4 is π+θ≤ω s When t≤2π, the first switch tube and the fifth switch tube are closed.

[0022] The present invention also provides a control method for the power distribution network power management circuit, comprising the following steps:

[0023] S1. Obtain parameter information of the target distribution network power management circuit;

[0024] S2. Determine the voltage control logic according to the data information obtained in step S1;

[0025] S3. Real-time acquisition of the load voltage of the power distribution network management circuit;

[0026] S4. Obtain the load voltage according to step S3, and calculate the control amount of the capacitor voltage based on the voltage control logic determined in step S2;

[0027] S5. Generate a phase shift angle based on the control quantity obtained in step S4, and modulate it with the carrier to generate a PWM drive signal, thereby achieving control of the target distribution network power management circuit.

[0028] The step S2 of determining the voltage control logic according to the data information obtained in step S1 specifically includes the following steps:

[0029] According to the data information obtained in step S1, the voltage expression of the loop composed of load, capacitor and distribution network is obtained as follows:

[0030] V g =V s +V o

[0031] Where V g is the distribution network voltage; V s is the capacitor voltage; V o is the load voltage;

[0032] Capacitor voltage V s To control, through the capacitor voltage V s With the distribution network voltage V g The superposition of the distribution network voltage V g Voltage management;

[0033] When the distribution network voltage V gWhen it is lower than the set value, the target distribution network power management circuit generates a voltage V g Capacitor voltage V in phase s , at this time the load voltage is expressed as V o =V g +|V s |;

[0034] When the distribution network voltage V g When the target distribution network power management circuit generates a voltage V at both ends of the capacitor that is equal to the distribution network voltage V g The capacitor voltage V s , at this time the load voltage is expressed as V o =V g -|V s |;

[0035] Finally, the negative electrode of the capacitor and the negative electrode of the distribution network are used as voltage output terminals to supply power to the external load.

[0036] The real-time acquisition of the load voltage of the power management circuit of the distribution network described in step S3 specifically includes the following steps:

[0037] A SOGI phase-locked loop is used to extract the voltage amplitude of the load voltage.

[0038] The step S4 of obtaining the load voltage according to the step S3 and calculating the control amount of the capacitor voltage based on the voltage control logic determined in the step S2 specifically includes the following steps:

[0039] The load voltage obtained in step S3 is compared with the set reference voltage, and the control amount of the capacitor voltage is calculated through the PI controller; it is expressed as

[0040]

[0041] Where k p is the proportional parameter of the PI controller; k i is the integral parameter of the PI controller; s is the Laplace operator; V oref is the set reference voltage value.

[0042] The distribution network power management circuit and control method thereof provided by the present invention arranges the distribution network power management circuit at the output end of the distribution network, and adopts a corresponding control algorithm to control the distribution network power management circuit; therefore, the present invention can not only realize the power management of the distribution network, ensure the stability of the power supply voltage of the distribution network, and improve the power supply quality of the distribution network, but also the scheme of the present invention only adopts one set of circuits to complete the corresponding management process, which is more reliable, simpler and more efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 Schematic diagram of the circuit architecture of the existing UPQC.

[0044] Figure 2 Schematic diagram of the circuit of the present invention.

[0045] Figure 3 The figure is a schematic diagram of the method flow of the present invention.

[0046] Figure 4 The control flow diagram of the method of the present invention is shown in FIG. DETAILED DESCRIPTION

[0047] The power distribution network power management circuit provided by the present invention comprises a transformer, a first full-bridge circuit, a second full-bridge circuit and a capacitor; the primary winding of the transformer is connected to the output end of the second full-bridge circuit, the input end of the second full-bridge circuit is connected to the distribution network and obtains the distribution network voltage; the secondary winding of the transformer is connected to the input end of the first full-bridge circuit, and the output end of the first full-bridge circuit is connected to the two ends of the capacitor; the positive electrode of the capacitor is connected to the positive electrode of the distribution network, and the negative electrode of the capacitor and the negative electrode of the distribution network are the output ends of the power distribution network power management circuit for external power supply; the second full-bridge circuit is used to transmit the voltage fluctuation signal to the first full-bridge circuit through the transformer when the distribution network voltage fluctuates; the first full-bridge circuit is used to generate an output voltage and load it on both ends of the capacitor to ensure the stability of the voltage signal at the output end of the power distribution network power management circuit.

[0048] like Figure 2 The circuit diagram of the circuit of the present invention is shown as follows: In the circuit diagram, the transformer, the first full-bridge circuit, the second full-bridge circuit and the capacitor of the power distribution network power management circuit, the rightmost element in the figure is the impedance, which is used to represent the load of the circuit; the specific connection relationship is:

[0049] The first full-bridge circuit includes a fifth switch tube T5, a sixth switch tube T6, a seventh switch tube T7, an eighth switch tube T8, a third capacitor C3 and a fourth capacitor C4; one end (emitter) of the action end of the fifth switch tube is connected to the other end (collector) of the action end of the sixth switch tube, one end (emitter) of the action end of the seventh switch tube is connected to the other end (collector) of the action end of the eighth switch tube, the other end (collector) of the action end of the fifth switch tube is connected to the other end (collector) of the action end of the seventh switch tube, and one end (emitter) of the action end of the sixth switch tube is connected to one end (emitter) of the action end of the eighth switch tube; the other end of the third capacitor is connected to the other end (collector) of the action end of the fifth switch tube, one end of the third capacitor is connected to the other end of the fourth capacitor, and one end of the fourth capacitor is connected to one end of the action end of the sixth switch tube; the secondary winding of the transformer is connected between one end of the action end of the fifth switch tube and one end of the third capacitor;

[0050] The second full-bridge circuit includes a first switch tube T1, a second switch tube T2, a third switch tube T3, a fourth switch tube T4, a first capacitor C1 and a second capacitor C2; one end (emitter) of the action end of the first switch tube is connected to the other end (collector) of the action end of the second switch tube, one end (emitter) of the action end of the third switch tube is connected to the other end (collector) of the action end of the fourth switch tube, the other end (collector) of the action end of the first switch tube is connected to the other end (collector) of the action end of the third switch tube, and one end (emitter) of the action end of the second switch tube is connected to one end (emitter) of the action end of the fourth switch tube; the other end of the first capacitor is connected to the other end (collector) of the action end of the first switch tube, one end of the first capacitor is connected to the other end of the second capacitor, and one end of the second capacitor is connected to one end of the action end of the second switch tube; the primary winding of the transformer is connected between one end of the action end of the first switch tube and one end of the first capacitor;

[0051] One end (emitter) of the action end of the fifth switch tube is connected to the negative electrode of the capacitor through the first filter inductor connected in series; one end (emitter) of the action end of the seventh switch tube is directly connected to one end (emitter) of the action end of the first switch tube; one end (emitter) of the action end of the seventh switch tube is also directly connected to the positive electrode of the capacitor; one end (emitter) of the action end of the third switch tube is connected to the negative electrode of the distribution network through the second filter inductor connected in series; the positive electrode of the distribution network is connected to the positive electrode of the capacitor; the load is connected between the negative electrode of the capacitor and the negative electrode of the distribution network;

[0052] The negative electrode of the capacitor and the negative electrode of the distribution network are the output ends of the distribution network power management circuit, which are connected to the external load.

[0053] The power distribution network power management circuit described above has the following working process:

[0054] Controlling the primary side voltage of the transformer through the first full-bridge circuit; controlling the capacitor voltage through the second full-bridge circuit;

[0055] When the distribution network voltage is low, low voltage control is carried out:

[0056] The fourth switch tube and the eighth switch tube form a group, and the third switch tube and the seventh switch tube form a group, and they are complementary turned on at a power frequency of 50 Hz;

[0057] The first switch tube and the second switch tube are a group, and the fifth switch tube and the sixth switch tube are a group, which are turned on at a high frequency of 50kHz; there is a phase shift angle θ between the bridge arms where the first switch tube and the second switch tube are located, and the bridge arms where the fifth switch tube and the sixth switch tube are located, and the duty cycle is 50%; in one switching cycle, there are four modes: Mode 1 is 0≤ω s When t≤θ, the first switch tube and the sixth switch tube are closed; Mode 2 is θ≤ω sWhen t≤π, the first switch tube and the fifth switch tube are closed; mode 3 is π≤ω s When t≤π+θ, the second switch tube and the fifth switch tube are closed; mode 4 is π+θ≤ω s When t≤2π, the second switch tube and the sixth switch tube are closed; ω s is the angular frequency; t is the time;

[0058] When the distribution network voltage is high, high voltage control is carried out:

[0059] The fourth switch tube and the seventh switch tube form a group, and the third switch tube and the eighth switch tube form a group, and they are complementary turned on at a power frequency of 50 Hz;

[0060] The first switch tube and the second switch tube are a group, and the fifth switch tube and the sixth switch tube are a group, which are turned on at a high frequency of 50kHz; there is a phase shift angle θ between the bridge arms where the first switch tube and the second switch tube are located, and the bridge arms where the fifth switch tube and the sixth switch tube are located, and the duty cycle is 50%; in one switching cycle, there are four modes: Mode 1 is 0≤ω s When t≤θ, the second switch tube and the fifth switch tube are closed; Mode 2 is θ≤ω s When t≤π, the second switch tube and the sixth switch tube are closed; Mode 3 is π≤ω s When t≤π+θ, the first switch tube and the sixth switch tube are closed; mode 4 is π+θ≤ω s When t≤2π, the first switch tube and the fifth switch tube are closed.

[0061] like Figure 3 The method flow chart of the method of the present invention is shown as follows: the control method of the power distribution network power management circuit disclosed in the present invention comprises the following steps:

[0062] S1. Obtain parameter information of the target distribution network power management circuit;

[0063] S2. Determine the voltage control logic according to the data information obtained in step S1; specifically, the steps include:

[0064] According to the data information obtained in step S1, the voltage expression of the loop composed of load, capacitor and distribution network is obtained as follows:

[0065] V g =V s +V o

[0066] Where V g is the distribution network voltage; V s is the capacitor voltage; V o is the load voltage;

[0067] Capacitor voltage V s To control, through the capacitor voltage V s With the distribution network voltage V g The superposition of the distribution network voltage V g Voltage management;

[0068] When the distribution network voltage V g When it is lower than the set value, the target distribution network power management circuit generates a voltage V g Capacitor voltage V in phase s , at this time the load voltage is expressed as V o =V g +|V s |;

[0069] When the distribution network voltage V g When the target distribution network power management circuit generates a voltage V at both ends of the capacitor that is equal to the distribution network voltage V g The capacitor voltage V s , at this time the load voltage is expressed as V o =V g -|V s |;

[0070] Finally, the negative electrode of the capacitor and the negative electrode of the distribution network are used as the output end of the power management circuit of the distribution network to supply power to the external load;

[0071] S3. Real-time acquisition of the load voltage of the power distribution network power management circuit; specifically includes the following steps:

[0072] The SOGI phase-locked loop is used to extract the voltage amplitude of the load voltage;

[0073] S4. Obtain the load voltage according to step S3, and calculate the control amount of the capacitor voltage based on the voltage control logic determined in step S2; specifically comprising the following steps:

[0074] The load voltage obtained in step S3 is compared with the set reference voltage, and the control amount of the capacitor voltage is calculated through the PI controller; it is expressed as

[0075]

[0076] Where k p is the proportional parameter of the PI controller; k i is the integral parameter of the PI controller; s is the Laplace operator; V oref is the set reference voltage value;

[0077] S5. According to the control amount obtained in step S4, a phase shift angle is generated and modulated with the carrier to generate a PWM drive signal, thereby realizing the control of the target distribution network power management circuit (the overall control process is as follows Figure 4 shown).

Claims

1. A power distribution network power management circuit, characterized in that It includes a transformer, a first full-bridge circuit, a second full-bridge circuit and a capacitor; the primary winding of the transformer is connected to the output end of the second full-bridge circuit, the input end of the second full-bridge circuit is connected to the distribution network and obtains the voltage of the distribution network; the secondary winding of the transformer is connected to the input end of the first full-bridge circuit, and the output end of the first full-bridge circuit is connected to the two ends of the capacitor; the positive electrode of the capacitor is connected to the positive electrode of the distribution network, and the negative electrode of the capacitor and the negative electrode of the distribution network are the output ends of the distribution network power management circuit for external power supply; the second full-bridge circuit is used to transmit the voltage fluctuation signal to the first full-bridge circuit through the transformer when the voltage of the distribution network fluctuates; The first full-bridge circuit is used to generate an output voltage and load it across the capacitor to ensure the stability of the voltage signal at the output end of the power distribution network power management circuit.

2. The power distribution network power management circuit according to claim 1 is characterized in that The transformer, the first full-bridge circuit, the second full-bridge circuit and the capacitor of the power distribution network power management circuit are specifically connected as follows: The first full-bridge circuit includes a fifth switch tube, a sixth switch tube, a seventh switch tube, an eighth switch tube, a third capacitor and a fourth capacitor; one end of the action end of the fifth switch tube is connected to the other end of the action end of the sixth switch tube, one end of the action end of the seventh switch tube is connected to the other end of the action end of the eighth switch tube, the other end of the action end of the fifth switch tube is connected to the other end of the action end of the seventh switch tube, and one end of the action end of the sixth switch tube is connected to one end of the action end of the eighth switch tube; the other end of the third capacitor is connected to the other end of the action end of the fifth switch tube, one end of the third capacitor is connected to the other end of the fourth capacitor, and one end of the fourth capacitor is connected to one end of the action end of the sixth switch tube; the secondary winding of the transformer is connected between one end of the action end of the fifth switch tube and one end of the third capacitor; The second full-bridge circuit includes a first switch tube, a second switch tube, a third switch tube, a fourth switch tube, a first capacitor and a second capacitor; one end of the action end of the first switch tube is connected to the other end of the action end of the second switch tube, one end of the action end of the third switch tube is connected to the other end of the action end of the fourth switch tube, the other end of the action end of the first switch tube is connected to the other end of the action end of the third switch tube, and one end of the action end of the second switch tube is connected to one end of the action end of the fourth switch tube; the other end of the first capacitor is connected to the other end of the action end of the first switch tube, one end of the first capacitor is connected to the other end of the second capacitor, and one end of the second capacitor is connected to one end of the action end of the second switch tube; the primary winding of the transformer is connected between one end of the action end of the first switch tube and one end of the first capacitor; One end of the action end of the fifth switch tube is connected to the negative electrode of the capacitor through the first filter inductor connected in series; one end of the action end of the seventh switch tube is directly connected to one end of the action end of the first switch tube; one end of the action end of the seventh switch tube is also directly connected to the positive electrode of the capacitor; one end of the action end of the third switch tube is connected to the negative electrode of the distribution network through the second filter inductor connected in series; the positive electrode of the distribution network is connected to the positive electrode of the capacitor; The negative electrode of the capacitor and the negative electrode of the distribution network are the output ends of the distribution network power management circuit, which are connected to the external load.

3. The power distribution network power management circuit according to claim 2 is characterized in that The power distribution network power management circuit described above has the following working process: Controlling the primary side voltage of the transformer through the first full-bridge circuit; controlling the capacitor voltage through the second full-bridge circuit; When the distribution network voltage is low, low voltage control is carried out: The fourth switch tube and the eighth switch tube form a group, and the third switch tube and the seventh switch tube form a group, and they are complementary turned on at a power frequency of 50 Hz; The first switch tube and the second switch tube are a group, and the fifth switch tube and the sixth switch tube are a group, which are turned on at a high frequency of 50kHz; there is a phase shift angle θ between the bridge arms where the first switch tube and the second switch tube are located, and the bridge arms where the fifth switch tube and the sixth switch tube are located, and the duty cycle is 50%; in one switching cycle, there are four modes: Mode 1 is 0≤ω s When t≤θ, the first switch tube and the sixth switch tube are closed; Mode 2 is θ≤ω s When t≤π, the first switch tube and the fifth switch tube are closed; mode 3 is π≤ω s When t≤π+θ, the second switch tube and the fifth switch tube are closed; mode 4 is π+θ≤ω s When t≤2π, the second switch tube and the sixth switch tube are closed; ω s is the angular frequency; t is the time; When the distribution network voltage is high, high voltage control is carried out: The fourth switch tube and the seventh switch tube form a group, and the third switch tube and the eighth switch tube form a group, and they are complementary turned on at a power frequency of 50 Hz; The first switch tube and the second switch tube are a group, and the fifth switch tube and the sixth switch tube are a group, which are turned on at a high frequency of 50kHz; there is a phase shift angle θ between the bridge arms where the first switch tube and the second switch tube are located, and the bridge arms where the fifth switch tube and the sixth switch tube are located, and the duty cycle is 50%; in one switching cycle, there are four modes: Mode 1 is 0≤ω s When t≤θ, the second switch tube and the fifth switch tube are closed; Mode 2 is θ≤ω s When t≤π, the second switch tube and the sixth switch tube are closed; Mode 3 is π≤ω s When t≤π+θ, the first switch tube and the sixth switch tube are closed; mode 4 is π+θ≤ω s When t≤2π, the first switch tube and the fifth switch tube are closed.

4. A control method for a power distribution network power management circuit according to any one of claims 1 to 3, characterized in that The steps include: S1. Obtain parameter information of the target distribution network power management circuit; S2. Determine the voltage control logic according to the data information obtained in step S1; S3. Real-time acquisition of the load voltage of the power distribution network management circuit; S4. Obtain the load voltage according to step S3, and calculate the control amount of the capacitor voltage based on the voltage control logic determined in step S2; S5. Generate a phase shift angle based on the control quantity obtained in step S4, and modulate it with the carrier to generate a PWM drive signal, thereby achieving control of the target distribution network power management circuit.

5. The control method according to claim 4, characterized in that The step S2 of determining the voltage control logic according to the data information obtained in step S1 specifically includes the following steps: According to the data information obtained in step S1, the voltage expression of the loop composed of load, capacitor and distribution network is obtained as follows: V g =V s +V o Where V g is the distribution network voltage; V s is the capacitor voltage; V o is the load voltage; Capacitor voltage V s To control, through the capacitor voltage V s With the distribution network voltage V g The superposition of the distribution network voltage V g Voltage management; When the distribution network voltage V g When it is lower than the set value, the target distribution network power management circuit generates a voltage V g Capacitor voltage V in phase s , at this time the load voltage is expressed as V o =V g +|V s |; When the distribution network voltage V g When the target distribution network power management circuit generates a voltage V at both ends of the capacitor that is equal to the distribution network voltage V g The capacitor voltage V s , at this time the load voltage is expressed as V o =V g -|V s |; Finally, the negative electrode of the capacitor and the negative electrode of the distribution network are used as the output end of the distribution network power management circuit to supply power to the external load.

6. The control method according to claim 5, characterized in that The real-time acquisition of the load voltage of the power management circuit of the distribution network described in step S3 specifically includes the following steps: A SOGI phase-locked loop is used to extract the voltage amplitude of the load voltage.

7. The control method according to claim 6, characterized in that The step S4 of obtaining the load voltage according to the step S3 and calculating the control amount of the capacitor voltage based on the voltage control logic determined in the step S2 specifically includes the following steps: The load voltage obtained in step S3 is compared with the set reference voltage, and the control amount of the capacitor voltage is calculated through the PI controller; it is expressed as Where k p is the proportional parameter of the PI controller; k i is the integral parameter of the PI controller; s is the Laplace operator; V oref is the set reference voltage value.

Images