Direct current ripple suppression circuit, motor and air conditioner

Abstract

According to the direct current ripple suppression circuit, the motor and the air conditioner provided by the utility model, by introducing the adjustable variable resistor, the absorption capacitor, the current sampling device and the voltage sampling device, effective absorption and suppression of ripple current in a direct current bus are realized. In the process, the controller calculates direct-current power based on the collected voltage and current signals, and power output is optimized by adjusting the resistance value of the variable resistor. And when the direct current power reaches the maximum value, the total loss of the whole system is minimum, so that the technical problem that the loss is relatively large when the direct current ripples are suppressed in related technologies is effectively solved, and the overall efficiency and stability of the system are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of direct current power systems, in particular to a direct current ripple suppression circuit, a motor and an air conditioner. Background Art

[0002] In DC power systems, ripple voltage and current are generated in the DC bus as load changes and conversion equipment (such as inverters and chargers) operate. This ripple not only increases system losses but also affects the stability and lifespan of power equipment. While traditional ripple absorption methods can reduce ripple, they often introduce significant losses in the absorption circuit itself, reducing overall system efficiency. Therefore, how to effectively absorb ripple while minimizing system losses and dynamically adjust the absorption circuit's performance under different operating conditions to minimize losses remains a pressing technical challenge.

[0003] In the related art, there is a technical problem that the loss is large when suppressing DC ripple. Summary of the Invention

[0004] The purpose of the present invention is to overcome the above technical deficiencies and provide a DC ripple suppression circuit, a motor and an air conditioner to solve the technical problem of large loss when suppressing DC ripple in the related art.

[0005] In order to achieve the above technical purpose, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present invention provides a DC ripple suppression circuit, which can be selectively connected to a DC bus, the DC bus being used to power a main circuit, and the DC ripple suppression circuit at least includes:

[0007] a variable resistor, one end of which is connected to the positive bus of the DC bus, for adjusting the magnitude of the current in the DC ripple suppression circuit;

[0008] an absorption capacitor, one end of which is connected to the other end of the variable resistor, and the other end of the absorption capacitor is connected to the negative bus of the DC bus, for absorbing DC ripple;

[0009] A voltage sampling device and a current sampling device, which are used to collect voltage and current signals of the DC bus respectively;

[0010] A controller, wherein the signal input end thereof is connected to the voltage sampling device and the current sampling device respectively to obtain the voltage and current signals; and the signal output end of the controller is connected to the variable resistor.

[0011] Furthermore, the DC ripple suppression circuit further includes:

[0012] A switch device has one end connected to the positive bus of the DC bus and the other end connected to one end of the variable resistor, and a control end of the switch device is connected to the controller.

[0013] Furthermore, the switching device is a relay.

[0014] Furthermore, the controller is a microcontroller, a digital signal processor or a field programmable gate array.

[0015] Furthermore, the DC ripple suppression circuit further includes:

[0016] A discharge resistor is connected in parallel with the absorption capacitor and is used to provide a discharge path for the absorption capacitor after the absorption capacitor is charged, so that the absorption capacitor can be discharged in time during the subsequent ripple absorption process.

[0017] Furthermore, the voltage sampling device includes:

[0018] A first voltage sampling device, one end of which is connected to the positive bus of the DC bus and is used to collect the positive voltage signal of the DC bus;

[0019] a second voltage sampling device, one end of which is connected to the negative bus of the DC bus and is used to collect the negative voltage signal of the DC bus;

[0020] An operational amplifier circuit, whose input end is respectively connected to the other end of the first voltage sampling device and the second voltage sampling device, and whose output end is connected to the controller, is used to process the received positive voltage signal and negative voltage signal and then input them into the controller.

[0021] Furthermore, the operational amplifier circuit includes:

[0022] a filter inductor, one end of which is connected to the other end of the first voltage sampling device and the other end of the second voltage sampling device, for suppressing high-frequency noise in the positive voltage signal and the negative voltage signal;

[0023] an operational amplifier, the input end of which is connected to the other end of the filter inductor, and is used to process the positive voltage signal and the negative voltage signal;

[0024] An LC filtering network is connected in parallel with the operational amplifier and is used to perform filtering processing on the positive voltage signal and the negative voltage signal.

[0025] Furthermore, the first voltage sampling device is a first sampling resistor, which is connected between the positive busbar of the DC bus and the first voltage sampling point; the second voltage sampling device is a second sampling resistor, which is connected between the negative busbar of the DC bus and the first voltage sampling point; wherein the first voltage sampling point and the second voltage sampling point are respectively connected to the input end of the operational amplifier circuit.

[0026] In a second aspect, the present invention provides a motor, which includes a DC ripple suppression circuit as described above.

[0027] In a third aspect, the present invention provides an air conditioner, comprising a DC ripple suppression circuit as described above.

[0028] Beneficial effects:

[0029] This utility model effectively absorbs and suppresses ripple current in the DC bus by introducing an adjustable variable resistor, an absorption capacitor, and current and voltage sampling devices. During this process, the controller calculates DC power based on the collected voltage and current signals and optimizes power output by adjusting the resistance of the variable resistor. When DC power reaches its maximum value, the total loss of the entire system is minimized, effectively resolving the technical issue of high loss when suppressing DC ripple in related technologies and improving the overall efficiency and stability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a block diagram of a DC ripple suppression circuit provided by an embodiment of the present utility model;

[0031] Figure 2 This is a block diagram of a DC ripple suppression circuit provided by an embodiment of the present utility model;

[0032] Figure 3 This is a block diagram of a DC ripple suppression circuit provided by an embodiment of the present utility model;

[0033] Figure 4 This is a block diagram of a voltage sampling device provided by an embodiment of the present utility model;

[0034] Figure 5 This is a flow chart of a control method for a DC ripple suppression circuit provided by an embodiment of the present utility model;

[0035] Figure 6 This is a flow chart of a control method for a DC ripple suppression circuit provided by an embodiment of the present utility model;

[0036] Figure 7 This is a flow chart of a control method for a DC ripple suppression circuit provided by an embodiment of the present utility model;

[0037] Figure 8 This is a circuit diagram of a DC ripple suppression circuit provided by an embodiment of the present utility model;

[0038] Figure 9 This is a circuit diagram of a DC ripple suppression circuit provided by an embodiment of the present utility model;

[0039] Figure 10 This is a block diagram of an electronic device used in an embodiment of the present utility model. DETAILED DESCRIPTION

[0040] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this application.

[0041] Overview:

[0042] DC power systems are widely used in a variety of fields, including photovoltaic power generation systems, energy storage systems, and electric vehicles. In these systems, the DC bus is used to transmit electrical energy, and theoretically, the DC voltage should remain constant. However, in actual operating environments, fluctuations in the DC voltage and current occur due to changes in system load and the operation of power conversion equipment (such as inverters and DC-DC converters). These fluctuations typically manifest as ripple voltage and current.

[0043] Ripple current has several negative effects. First, it increases reactive power in the system, reducing energy transmission efficiency. Second, it can increase the temperature of power equipment, shorten the life of electronic components, and even cause system instability in some sensitive equipment. Therefore, suppressing and absorbing this ripple has become a key issue in designing efficient DC power systems.

[0044] In related technologies, ripple suppression primarily relies on introducing a snubber circuit into the DC bus, using a snubber capacitor to absorb the ripple current. However, while these snubber methods can reduce ripple to a certain extent, the snubber circuit itself consumes energy. Especially under high-power conditions, the snubber circuit can generate significant losses, which in turn reduces overall system efficiency.

[0045] Furthermore, the absorption circuits in related technologies often use fixed-resistance resistors. Under varying operating conditions, these resistors cannot be dynamically adjusted based on the actual ripple conditions, making it difficult to effectively balance the absorption effect and energy loss of the system. In particular, under conditions of large load variations or high power, fixed-resistance absorption circuits often struggle to cope with complex ripple variations, leading to increased system losses.

[0046] Therefore, in the related art, there is a technical problem that the loss is large when suppressing the DC ripple.

[0047] Example

[0048] like Figure 1 As shown, this embodiment provides a DC ripple suppression circuit, which can be selectively connected to a DC bus, and the DC bus is used to power a main circuit.

[0049] Specifically, the main circuit can be represented as a closed power transmission loop formed by the DC bus. Within this loop, electrical energy is transferred from the power source to the load through energy conversion modules (e.g., inverter circuits, rectifier circuits, and DC-DC converter circuits). After being consumed by the load or stored in an energy storage device, it returns to the power source, forming an energy closed loop. This main circuit may include: a load powered by the DC bus, modules that perform energy conversion, and core circuitry that performs functions such as energy storage and protection.

[0050] In a photovoltaic power generation system, the primary circuit can be a closed power loop from the photovoltaic panels to the load or the grid. More specifically, the photovoltaic panels generate direct current (DC), which is combined into a DC busbar via a DC combiner box. This energy then passes through a photovoltaic inverter, converting the DC power into alternating current (for AC loads or grid connection), or directly through a DC-DC converter for voltage regulation (for DC loads). The converted energy then flows to the load (such as household electricity or industrial equipment) or the grid (for grid-connected power generation), forming a closed energy transmission loop.

[0051] In an energy storage system, the primary circuit can be a closed electrical circuit formed during the charging and discharging process, whereby the battery pack's electrical energy flows through a bidirectional DC-DC converter and inverter to the load or grid. More specifically, the battery pack stores electrical energy, which is then transmitted to the load or grid via a DC bus. During discharge, the energy passes through a bidirectional DC-DC converter, where the voltage is adjusted to meet the load's requirements. If the load is an AC device, the energy can also be converted from DC to AC via a bidirectional inverter, which can then be supplied to the AC load or fed into the grid. During charging, energy from the grid or renewable energy sources (such as photovoltaic or wind power) enters the DC bus through an inverter or DC-DC converter, charging the battery pack and completing the energy circuit.

[0052] The DC ripple suppression circuit may include:

[0053] A variable resistor, one end of which is connected to the positive bus of the DC bus, is used to adjust the magnitude of the current in the DC ripple suppression circuit.

[0054] In this embodiment, the variable resistor can be represented as a resistance element whose resistance value can be adjusted by mechanical or electronic means. In the DC ripple suppression circuit, the variable resistor is connected to the positive bus of the DC bus and plays a role in adjusting the current size in the DC ripple suppression circuit. The resistance value of the variable resistor can be increased or decreased through real-time adjustment of the controller, which will directly affect the current flow in the DC ripple suppression circuit and thus adjust the absorption efficiency of the DC bus ripple current. Specifically: when the resistance value of the variable resistor increases, the current of the DC ripple suppression circuit decreases and the effect of absorbing the ripple current is weakened; when the resistance value of the variable resistor decreases, the current of the DC ripple suppression circuit increases, absorbing more ripple current, thereby suppressing the fluctuation of the ripple voltage.

[0055] In this embodiment, the variable resistor may be a digitally controllable resistor. It is understood that a digitally controllable resistor is an electronic component whose resistance is controlled by a digital signal and can be connected to a controller via a digital communication protocol (eg, I²C or SPI).

[0056] In this embodiment, the variable resistor may be a programmable resistor. It is understood that the programmable resistor can adjust its resistance value in real time according to the instruction of the controller, thereby accurately controlling the current in the DC ripple suppression circuit.

[0057] In this embodiment, the variable resistor can also be a MOSFET (field-effect transistor). Specifically, the current between the source and drain electrodes can be adjusted using a gate control signal, effectively acting as a variable resistor. It is understood that MOSFET resistance adjustment is achieved by controlling the gate voltage, enabling dynamic current regulation in DC ripple suppression circuits. The controller outputs signals that can change the MOSFET's on-resistance in real time, achieving precise current control.

[0058] In this embodiment, the variable resistor may also be an IGBT (Insulated Gate Bipolar Transistor). Specifically, by controlling a gate drive signal, the IGBT can also adjust the magnitude of the output current.

[0059] In this embodiment, the variable resistor may also be an electronic load.

[0060] An absorption capacitor, one end of which is connected to the other end of the variable resistor, and the other end of the absorption capacitor is connected to the negative bus of the DC bus, for absorbing DC ripple.

[0061] In this embodiment, in this DC ripple suppression circuit, one end of the absorption capacitor is connected to the other end of the variable resistor, and the other end is connected to the negative busbar of the DC bus, forming an absorption loop. When ripple current flows through the DC bus in the circuit, the absorption capacitor, through its charge storage capacity, stores excess energy when the ripple current arrives and releases the charge after the ripple current disappears, effectively suppressing voltage fluctuations and smoothing the DC voltage.

[0062] As you can understand, snubber capacitors absorb high-frequency ripple and noise, reducing the amplitude of fluctuations and smoothing the voltage. When the DC bus voltage rises, the snubber capacitor charges and stores energy. When the voltage drops, the snubber capacitor releases energy to maintain voltage stability. When ripple voltage is present in the DC power supply output, the snubber capacitor effectively absorbs this ripple current, reducing voltage fluctuations and thus improving the overall stability of the DC power system. Because the snubber capacitor responds quickly to voltage fluctuations, it can effectively suppress higher-frequency ripple.

[0063] In this embodiment, when the variable resistor is a programmable resistor, one end of the absorption capacitor is connected to the other end of the programmable resistor, and one end of the programmable resistor is connected to the positive busbar of the DC bus. The other end of the absorption capacitor is connected to the negative busbar of the DC bus, forming an absorption loop. The programmable resistor can adjust its resistance value according to the controller's instructions, thereby changing the current in the absorption loop and controlling the charging and discharging behavior of the absorption capacitor.

[0064] In this embodiment, when the variable resistor is a MOSFET, one end of the absorption capacitor is connected to the drain of the MOSFET, and the source of the MOSFET is connected to the negative bus of the DC bus. The gate of the MOSFET is regulated by a controller to adjust its control signal, thereby adjusting the resistance value between the source and the drain. The controller changes the resistance value between the drain and the source by adjusting the gate voltage of the MOSFET, thereby controlling the current passing through the absorption capacitor in the absorption circuit. The absorption capacitor absorbs the ripple current in the DC bus. When ripples occur, the MOSFET adjusts the current to ensure that the absorption capacitor smooths out voltage fluctuations.

[0065] In this embodiment, when the variable resistor is an IGBT, one end of the absorption capacitor is connected to the collector of the IGBT, and the emitter of the IGBT is connected to the negative bus of the DC bus. The gate of the IGBT is regulated by a controller signal, controlling the on and off of the IGBT, thereby regulating the current in the absorption circuit. In one possible implementation, the controller can adjust the gate signal of the IGBT based on changes in DC power to control the current flow between the collector and emitter. The absorption capacitor implements dynamic current regulation through the IGBT to suppress ripple voltage.

[0066] In this embodiment, when the variable resistor is an electronic load, one end of the absorption capacitor is connected to the input terminal of the electronic load, and the other end of the electronic load is connected to the negative bus of the DC bus. The electronic load adjusts its load magnitude via a controller signal, thus acting as an adjustable resistor, controlling the current in the absorption circuit.

[0067] The voltage sampling device and the current sampling device are used to collect the voltage and current signals of the DC bus respectively.

[0068] In this embodiment, the current sampling device can collect the current signal of the DC bus and transmit it to the controller.

[0069] In this embodiment, the current sampling device may be a Hall-effect current sensor. A Hall-effect current sensor can detect the current flowing through a conductor and sense the magnitude of the current through a magnetic field. It is understood that the Hall-effect current sensor can be installed in a non-contact manner around the positive busbar of the DC bus. Measurements can be performed by sensing the magnetic field generated by the current flowing through the positive busbar.

[0070] In this embodiment, the current sampling device may be a shunt resistor. It is understood that a shunt resistor is a low-resistance precision resistor that can be connected in series with a DC bus. The voltage drop across the shunt resistor can be measured to indirectly calculate the current flowing through the DC bus.

[0071] In this embodiment, the current sampling device may be an integrated circuit current sensor. It is understood that the integrated current sensor chip has a built-in high-precision current measurement circuit that can collect the current signal of the DC bus.

[0072] In this embodiment, the voltage sampling device can collect the voltage signal of the DC bus.

[0073] In this embodiment, the voltage sampling device can be a voltage-dividing resistor circuit. Specifically, the voltage-dividing resistor circuit can be a voltage-dividing resistor circuit formed by two precision resistors connected in series. The high voltage of the DC bus passes through the voltage-dividing resistor circuit, and the voltage is divided into a smaller proportion. This smaller voltage can be safely sent to the controller for measurement. More specifically, one resistor can be connected to the positive pole of the DC bus, and the other resistor can be connected to the negative pole of the DC bus. The midpoint of the connection between the two resistors is the sampling node, and the voltage signal of the sampling node is transmitted to the controller for measurement after voltage division.

[0074] In this embodiment, the voltage sampling device may be an isolation amplifier circuit. Specifically, the input of the isolation amplifier circuit may be connected to the positive terminal of the DC bus to measure the bus voltage. The output of the isolation amplifier circuit is isolated from the controller circuit and outputs a low-voltage signal. In this manner, the DC bus voltage can be sampled in real time without compromising electrical isolation.

[0075] In this embodiment, the voltage sampling device may also be a voltage sampling integrated circuit. The voltage sampling integrated circuit can process the measured voltage signal through internal voltage division and amplification, convert it into a digital signal through a built-in ADC, and then send the measurement result to the controller through a digital communication interface.

[0076] The voltage and current signals can be either analog or digital. It is understood that the voltage sampling device (e.g., a voltage divider resistor circuit) can directly acquire the voltage signal from the DC bus and, after voltage division or other processing, output an analog voltage signal. This analog signal is proportional to the DC bus voltage and is a continuously changing voltage value. For example, when the DC bus voltage is 400V, the output of the voltage divider resistor circuit may be an analog signal in the range of 0 to 5V. The analog signal is directly transmitted to the controller's analog-to-digital converter (ADC), which converts it into a digital signal for processing. The current sampling device (e.g., a Hall effect current sensor) directly acquires the signal from the DC bus current and outputs an analog current signal.

[0077] In some embodiments, a voltage sampling device (e.g., a voltage sensor with a built-in ADC or a digital voltage sensor) can directly convert an analog voltage signal into a digital output. This digital signal can be transmitted to a controller via a communication protocol. Digital signals are quantized voltage values, represented as binary numbers, and can be directly read by the controller without further analog-to-digital conversion. A digital current sensor (e.g., a Hall-effect sensor with a built-in ADC) can convert the detected current signal into a digital output. This digital current signal can also be directly transmitted to the controller via a communication protocol.

[0078] a controller, which is at least respectively connected to the variable resistor, the current sampling device, and the voltage sampling device, and is capable of calculating the DC power of the DC bus based on the voltage and current signals, and adjusting the resistance value of the variable resistor based on changes in the DC power, so that when the DC power reaches a maximum value, the sum of the loss of the DC ripple suppression circuit and the loss of the main circuit is minimized.

[0079] In a DC power system, maximizing DC power maximizes the system's energy conversion efficiency and minimizes total losses across the entire circuit. DC power is the product of the system's voltage and current and represents the effective power delivered to the load. When DC power reaches its maximum value, voltage and current fluctuations are minimized, energy loss in the system is minimized, and more energy is effectively utilized rather than dissipated in losses. Total loss is a measure of reactive power. Total loss includes losses in the DC ripple suppression circuit and the main circuit. These losses primarily stem from reactive power in the circuit (e.g., losses due to resistor heating and ripple current). Maximizing DC power minimizes reactive power, maximizing the system's effective energy utilization, and minimizing total losses in the DC ripple suppression circuit and the main circuit. When the variable resistor is adjusted to the optimal point, current and voltage fluctuations (ripple) are most effectively suppressed, and the DC voltage tends to be stable. In this case, additional power losses caused by ripple current in the system (e.g., electromagnetic losses or resistor heat losses due to current fluctuations) are reduced, minimizing total losses.

[0080] In this embodiment, the controller may be connected to the variable resistor to output a control signal to the variable resistor to adjust the resistance of the variable resistor.

[0081] In this embodiment, the controller may be connected to the current sampling device and the voltage sampling device to receive the voltage and current signals transmitted by the current sampling device and the voltage sampling device.

[0082] In this embodiment, the controller can calculate the DC power of the DC bus based on the collected voltage and current signals using the formula P = U × I (power = voltage × current). By continuously collecting power, the controller can analyze power variations and determine how to adjust the resistance of the variable resistor to optimize the circuit's energy efficiency. Based on the power calculation results, the controller can dynamically adjust the resistance of the variable resistor to maximize the DC power. This minimizes total losses and optimizes ripple suppression. The controller can achieve this by sending a control signal (e.g., a PWM signal or a digital control signal) to the variable resistor (e.g., a MOSFET, IGBT, electronic load, etc.) to adjust its resistance. The controller can also use closed-loop feedback control to continuously monitor the voltage and current signals and dynamically adjust the resistance of the variable resistor to maintain DC bus stability and ripple suppression under changing operating conditions. Specifically, the controller can first collect the voltage and current signals transmitted by the voltage sampling device and the current sampling device via an ADC or a digital communication interface. The controller can then calculate the current DC power of the DC bus using the formula P = U × I. Finally, the controller can adjust the resistance of the variable resistor based on the changes in DC power to keep the DC power system running at the maximum DC power.

[0083] In this embodiment, the maximum value can be expressed as the maximum effective power achievable by the DC power system. When the controller adjusts the variable resistor to control the voltage and current fluctuations of the DC bus, the system enters a power optimum, i.e., a state where DC power is maximized. In this state, total system losses (including losses in the DC ripple suppression circuit and the main circuit) are minimized.

[0084] Specifically, the maximum value may be a preset maximum value. The preset maximum value may be a fixed value. The preset maximum value may be obtained through experiments or simulation calculations. For example, by conducting multiple experiments on the DC power system and adjusting parameters such as the variable resistor and absorption capacitor in the system, the power peak of the system under different working conditions can be found. After recording these peak powers, these values ​​can be stored in the controller as preset maximum values. The voltage fluctuations and current changes of the DC bus can be simulated by performing circuit simulation on the entire circuit. Through the simulation tool, the maximum power output point of the system can be found and stored in the controller as a preset value.

[0085] Specifically, the maximum value can be a maximum value obtained through real-time calculation. This maximum value obtained through real-time calculation is adjusted by the controller during operation based on the collected voltage and current signals through dynamic feedback and optimization algorithms until the DC power is maximized. Therefore, in this case, the maximum value is not fixed, but changes continuously according to the real-time operation of the DC power system. More specifically, the controller can continuously collect the voltage and current of the DC bus through a voltage sampling device and a current sampling device to calculate the current DC power. The controller can change the current in the absorption circuit by adjusting the resistance of the variable resistor, thereby affecting the voltage fluctuation of the DC bus. The controller can detect the change in DC power after each adjustment through closed-loop feedback control. If the DC power increases, the variable resistor is further adjusted. If the DC power decreases, the adjustment is made in the opposite direction until the DC power reaches its peak value.

[0086] In this embodiment, the controller may be preset with a linear control algorithm (e.g., PID control algorithm) or an advanced optimization algorithm (e.g., particle swarm algorithm, ant colony algorithm) to dynamically optimize the resistance of the variable resistor to ensure that the DC power system achieves minimum loss under different operating conditions.

[0087] The losses in the DC ripple suppression circuit can be represented as losses caused by the DC ripple suppression circuit itself. It is understood that in order to absorb ripple current and voltage fluctuations to stabilize the DC bus, the DC ripple suppression circuit often requires the introduction of several components, such as absorption capacitors and control switches. These components generate different types of losses during operation.

[0088] Specifically, the losses of the DC ripple suppression circuit may include:

[0089] Variable resistor losses: The primary function of a variable resistor is to regulate the current in the absorption circuit to effectively absorb ripple current. However, according to Joule's law, when current passes through the variable resistor, some of the energy is dissipated as heat, resulting in thermal losses. This loss is calculated using the formula P=I²R, where I is the current passing through the variable resistor and R is the resistance of the variable resistor. When the controller adjusts the variable resistor's value to reduce ripple, the change in resistance directly affects the current magnitude and losses. A higher resistance value limits the current flow, reducing current losses, but may not be sufficient to absorb ripple. A lower resistance value allows more current to flow, potentially increasing ripple absorption effectiveness, but also increasing thermal losses. Therefore, it is necessary to find a balance in resistance value that effectively absorbs ripple while minimizing losses.

[0090] Losses in the snubber capacitor: It's understandable that the primary function of the snubber capacitor is to absorb ripple current and smooth voltage fluctuations on the DC bus through charging and discharging. However, the snubber capacitor generates a certain amount of equivalent series resistance (ESR) losses during the charging and discharging process. This ESR causes some of the electrical energy to be dissipated as heat within the snubber capacitor, especially during frequent charge and discharge cycles. When the ripple current frequency is high, the charge and discharge rate of the snubber capacitor also increases, resulting in greater energy loss. Therefore, the ESR value and size of the snubber capacitor directly affect the extent of the losses. A larger snubber capacitor can better smooth voltage fluctuations, but it also results in greater charge and discharge losses.

[0091] Switching device losses: The switching device connects the absorption circuit to the DC bus. Switching devices generate certain switching losses when they are turned on or off, especially conduction losses during the switching process.

[0092] Discharge resistor losses: In some cases, a discharge resistor may be included in a DC ripple suppression circuit. Connected in parallel across the snubber capacitor, the discharge resistor provides a discharge path for the snubber capacitor when not in operation, preventing it from remaining charged for extended periods. When the snubber capacitor discharges through the discharge resistor, some of the energy is dissipated in the discharge resistor.

[0093] It is understood that the main circuit is the core circuit of the entire power system, connecting the load and the power supply. The losses in the main circuit can include:

[0094] Ripple current losses: Ripple current in a DC bus refers to the AC component it contains. When ripple current is conducted through the main circuit, it causes additional losses in equipment and wiring. High-frequency ripple, in particular, can lead to skin effect in conductors, increasing their effective resistance and leading to increased heat loss. Ripple current can also generate electromagnetic interference, affecting the normal operation of surrounding electronic equipment. To reduce this interference, additional filters or shielding are often required, which also increases losses in the main circuit.

[0095] Inductor component losses: If an inductor is present in the main circuit, conducting high-frequency ripple current will generate core and copper losses. Core losses are caused by hysteresis and eddy current losses in the iron core due to the high-frequency magnetic field; copper losses are caused by heat loss due to the resistance of the wires in the inductor coil. High-frequency ripple, in particular, significantly increases these losses. The presence of high-frequency ripple significantly increases core and copper losses in the inductor because the high-frequency current generates higher current density and skin effect in the wires, causing the inductor component to heat up and dissipate more energy.

[0096] Load device losses: Load devices in the main circuit (e.g., inverters, motors, batteries, etc.) can also experience reduced efficiency due to ripple current and voltage fluctuations. Most load devices are designed to operate from a stable DC power supply. When voltage and current fluctuate, the power devices (e.g., IGBTs, MOSFETs) within the device may operate suboptimally, increasing switching and conduction losses. Load devices are highly sensitive to voltage and current, especially when the fluctuations are large. This reduces power conversion efficiency within the load device, increasing losses within the load device itself.

[0097] Therefore, when the DC power reaches its maximum value, the proportion of active power transferred to the load is maximized, minimizing system energy losses (such as resistor heat loss and ripple current loss). Reactive power (such as heat loss and conduction loss) in the system is minimized, which directly reduces the total losses in the DC ripple suppression circuit and the main circuit. When dynamically adjusting the variable resistor, reaching the maximum DC power value indicates optimal system operation. At this point, ripple current and voltage fluctuations are minimized, maximizing system stability and reliability. Therefore, finding the maximum DC power value is key to ensuring efficient and stable system operation.

[0098] In this embodiment, the controller may be a microcontroller (MCU). It will be understood that a microcontroller is an embedded controller with integrated ADC, PWM output, communication interface (e.g., I²C, SPI, UART), and other functions, capable of performing the aforementioned operations of calculating the DC power of the DC bus based on the voltage and current signals, and adjusting the resistance value of the variable resistor based on changes in the DC power, thereby minimizing the sum of the losses of the DC ripple suppression circuit and the losses of the main circuit when the DC power reaches a maximum value.

[0099] In this embodiment, the controller may be a digital signal processor (DSP), capable of sampling voltage and current signals at high speed and performing rapid power calculation and regulation control.

[0100] In this embodiment, the controller may be a field programmable gate array (FPGA). It is understood that a FPGA is a hardware programmable logic device capable of parallel processing. It can perform ultra-high-speed data acquisition, power calculation, and control operations.

[0101] In this embodiment, the controller may also be an application specific integrated circuit (ASIC).

[0102] In this embodiment, the controller may also be an embedded system. For example, the embedded system may be an embedded system based on a Linux operating system. The embedded system based on a Linux operating system may perform the aforementioned operations of calculating the DC power of the DC bus based on the voltage and current signals, and adjusting the resistance value of the variable resistor based on changes in the DC power, so that when the DC power reaches a maximum value, the sum of the loss of the DC ripple suppression circuit and the loss of the main circuit is minimized.

[0103] This embodiment effectively absorbs and suppresses ripple current in the DC bus by introducing an adjustable variable resistor, an absorption capacitor, and a DC ripple suppression circuit equipped with current and voltage sampling devices. During this process, the controller dynamically calculates DC power based on real-time collected voltage and current signals and optimizes power output by adjusting the resistance of the variable resistor. When the DC power reaches its maximum value, the total loss of the entire system is minimized, effectively resolving the technical issue of high losses in suppressing DC ripple in the prior art and improving the overall efficiency and stability of the system. Specifically, by flexibly adjusting the resistance of the variable resistor, this embodiment achieves optimal ripple absorption under different operating conditions and effectively reduces energy waste. Real-time acquisition of current and voltage signals provides the controller with accurate data support, enabling the DC ripple suppression circuit to adjust the resistance of the variable resistor based on the changing trend of DC power, ensuring operation at the maximum power point and reducing overall losses. When the DC power reaches its maximum value, the overall loss is minimized, successfully resolving the high loss issue in the prior art and improving the efficiency and stability of the entire DC ripple suppression circuit.

[0104] In some cases, and in some technical solutions, the DC ripple suppression circuit is continuously connected to the DC bus, unable to flexibly adjust according to real-time conditions. This approach leaves the circuit connected even when DC bus voltage fluctuations are minimal or ripple current is insignificant, resulting in unnecessary energy loss. The variable resistor and absorption capacitor in the DC ripple suppression circuit still cause power loss even when there is no ripple current to absorb, impacting overall energy efficiency. When the DC ripple suppression circuit is constantly connected, current passing through the resistor generates heat, increasing overall power loss in both static and dynamic conditions. This power loss is particularly significant under high ripple or low load conditions, reducing system efficiency and even causing overheating and damage to equipment. Furthermore, due to current and voltage fluctuations, the continuously connected ripple suppression circuit may cause equipment to operate under suboptimal conditions, impacting performance and stability. For example, loads such as motors and inverters may experience reduced efficiency when operating with unstable power, increasing failure rates and maintenance costs.

[0105] In response to the above problems, such as Figure 2 As shown, in some embodiments, the DC ripple suppression circuit further includes:

[0106] A switching device, one end of which is connected to the positive bus of the DC bus and the other end is connected to one end of the variable resistor, and a control end of the switching device is connected to the controller, for selectively connecting or disconnecting the DC ripple suppression circuit from the DC bus based on an instruction issued by the controller.

[0107] In this embodiment, the switching device may be a relay. It is understood that a relay is an electrical control device that uses electromagnetic principles to achieve automatic switching control. A relay may consist of a coil, contacts, and a spring. When the coil is energized, the generated magnetic field attracts the contacts, connecting or disconnecting the circuit. When the controller sends a signal, the relay coil is energized, the contacts close, and the DC ripple suppression circuit is connected to the DC bus. When the control signal is disconnected, the contacts open, disconnecting the DC ripple suppression circuit from the DC bus.

[0108] In this embodiment, the switching device may be a MOSFET. It will be appreciated that when a controller applies a control signal to the gate of the MOSFET, the MOSFET turns on, allowing current to flow from the source to the drain. When the gate signal disappears or drops below a threshold, the MOSFET turns off, cutting off the current.

[0109] In this embodiment, the switching device may also be an IGBT. When the controller applies a voltage to the gate of the IGBT, the IGBT turns on, allowing current to flow; when the gate voltage drops below a certain value, the IGBT turns off the current flow.

[0110] In this embodiment, the switching device may also be a solid-state relay.

[0111] In this embodiment, the switching device may also be an electronic switch.

[0112] In this embodiment, by introducing a switching device, the DC ripple suppression circuit is selectively connected or disconnected. This flexible control capability enables the DC power system to adjust the ripple current absorption effect according to actual needs, thereby improving energy transmission efficiency, stability, and flexibility. By selectively connecting the DC ripple suppression circuit, the fluctuations of ripple current and voltage can be effectively suppressed, making the DC voltage more stable and improving the stability and reliability of the DC power system. By selectively disconnecting the DC ripple suppression circuit, the ineffective power loss can be reduced and the energy utilization efficiency can be improved. This setting can make the DC power system operate more efficiently, extend the service life of the equipment, and adapt to different working conditions and load changes.

[0113] In some cases, the absorption capacitor in the DC ripple suppression circuit may remain charged for a long time after being charged. This may cause the absorption capacitor to be unable to provide support for subsequent ripple absorption in a timely manner, thereby affecting the overall performance and response speed of the DC ripple suppression circuit.

[0114] In response to the above problems, such as Figure 3 As shown, in some embodiments, the DC ripple suppression circuit further includes:

[0115] A discharge resistor is connected in parallel with the absorption capacitor and is used to provide a discharge path for the absorption capacitor after the absorption capacitor is charged, so that the absorption capacitor can be discharged in time during the subsequent ripple absorption process.

[0116] In this embodiment, the design of providing a discharge resistor in parallel with the absorption capacitor can effectively improve the performance and reliability of the DC ripple suppression circuit. When the absorption capacitor is fully charged, the discharge resistor provides an effective discharge path, allowing the absorption capacitor to quickly release the stored electrical energy, ensuring timely discharge during the subsequent ripple absorption process. This design not only improves the absorption capacitor's response speed to frequent ripples and enhances the dynamic performance of the DC ripple suppression circuit, but also prevents the risk of overcharging caused by the absorption capacitor remaining charged for a long time, reducing the probability of failure, thereby enhancing the stability and safety of the entire system.

[0117] In some cases, voltage sampling techniques used in related technologies may not accurately and in real time reflect the voltage status of the DC bus, resulting in delayed response to power fluctuations, which in turn affects the stability and efficiency of the overall system. Furthermore, when collecting positive and negative voltage signals, voltage sampling devices used in related technologies may experience signal attenuation and noise interference, significantly reducing sampling accuracy, especially in high-frequency ripple environments.

[0118] Therefore, in some embodiments, Figure 4 As shown, the voltage sampling device may include:

[0119] The first voltage sampling device has one end connected to the positive bus of the DC bus and is used to collect the positive voltage signal of the DC bus.

[0120] In this embodiment, one end of a first voltage sampling device is connected to the positive busbar of the DC bus. This first voltage sampling device may be a voltage divider resistor. The primary function of the first voltage sampling device is to monitor the voltage level of the DC bus positive electrode in real time. The voltage divider resistor reduces high voltage signals to an acceptable range, ensuring suitability for subsequent processing and analysis.

[0121] The second voltage sampling device has one end connected to the negative bus of the DC bus and is used to collect the negative voltage signal of the DC bus.

[0122] In this embodiment, one end of the second voltage sampling device is connected to the negative busbar of the DC bus. This second voltage sampling device can be a voltage divider resistor. The primary function of the second voltage sampling device is to monitor the voltage level of the negative terminal of the DC bus in real time. The voltage divider resistor reduces the high voltage signal to an acceptable range, ensuring that it is suitable for subsequent processing and analysis.

[0123] An operational amplifier circuit, whose input end is respectively connected to the other end of the first voltage sampling device and the second voltage sampling device, and whose output end is connected to the controller, is used to process the received positive voltage signal and negative voltage signal and then input them into the controller.

[0124] In this embodiment, the inputs of the operational amplifier circuit are connected to the outputs of the first and second voltage sampling devices, respectively. The operational amplifier inputs receive signals from the two sampling devices to process the positive and negative voltages. The operational amplifier circuit amplifies and processes the positive and negative voltage signals. After amplification, the signals are transmitted to a controller for further calculation and analysis.

[0125] This technical solution effectively improves the accuracy and stability of voltage signal acquisition by introducing first and second voltage sampling devices, combined with an operational amplifier circuit. The operational amplifier can amplify and process both positive and negative voltage signals, ensuring that the voltage signal received by the controller is accurate and clear. This enables more effective ripple suppression and power management, significantly improving responsiveness to voltage fluctuations and addressing shortcomings in related technologies.

[0126] In some cases, voltage sampling and signal processing techniques used in related technologies may not effectively filter out high-frequency noise and interference from the DC bus voltage signal. This can cause the controller to receive unstable or inaccurate voltage signals, impacting the performance and responsiveness of the entire system. The presence of high-frequency noise not only reduces measurement accuracy but can also interfere with subsequent signal processing and power regulation, further compromising the effectiveness of DC ripple suppression.

[0127] Therefore, in some embodiments, the operational amplifier circuit includes:

[0128] A filter inductor, one end of which is connected to the other end of the first voltage sampling device and the other end of the second voltage sampling device, is used to suppress high-frequency noise in the positive voltage signal and the negative voltage signal.

[0129] In this embodiment, the filter inductor functions to suppress high-frequency noise in the positive and negative voltage signals passing through the first and second voltage sampling devices. When high-frequency noise signals flow through the filter inductor, they create impedance for the high-frequency signals, thereby reducing the amplitude of the noise signals and ensuring a smoother and more stable output voltage signal.

[0130] The operational amplifier has an input end connected to the other end of the filter inductor and is used to process the positive voltage signal and the negative voltage signal.

[0131] In this embodiment, the operational amplifier can receive the positive and negative voltage signals processed by the filter inductor and further amplify and process these signals. The operational amplifier can increase the strength of the signal to make it suitable for subsequent analysis and calculation by the controller.

[0132] An LC filtering network is connected in parallel with the operational amplifier and is used to perform filtering processing on the positive voltage signal and the negative voltage signal.

[0133] In this embodiment, an LC filter network is connected in parallel with the operational amplifier to further filter the positive and negative voltage signals, thereby further reducing high-frequency noise and voltage fluctuations in the signals and improving signal stability.

[0134] This embodiment effectively improves the processing performance of the DC bus voltage signal through the design of an operational amplifier circuit, combined with a filter inductor, an operational amplifier, and an LC filter network. The filter inductor can suppress high-frequency noise in the positive and negative voltage signals, improving the clarity and stability of the signal; the operational amplifier is used to amplify the processed voltage signal to ensure that the controller receives a signal of appropriate strength and accuracy; the LC filter network further smoothes the output signal, reduces fluctuations, and improves the system's anti-interference ability. In summary, this embodiment significantly improves the response speed to voltage fluctuations and overall performance, ensuring the reliable operation of the DC ripple suppression circuit in a dynamic environment.

[0135] like Figure 8 and Figure 9 In a specific embodiment, a DC ripple suppression circuit is provided. The DC ripple suppression circuit may include:

[0136] The relay K1 has one end connected to the positive bus of the DC bus and is used to control the DC ripple suppression circuit to be connected to the DC bus or disconnected from the DC ripple suppression circuit. The control end of the relay K1 can be connected to the controller.

[0137] The variable resistor Rn has one end connected to the positive bus of the DC bus through the relay K1 and is used to adjust the current in the DC ripple suppression circuit.

[0138] An absorption capacitor C1 has one end connected to the other end of the variable resistor Rn, and the other end of the absorption capacitor C1 is connected to the negative bus of the DC bus for absorbing DC ripple.

[0139] The voltage sampling device includes a sampling resistor R1 and a sampling resistor R2.

[0140] Specifically, sampling resistor R1 is connected between the DC bus's positive pole (DC+) and the voltage sampling point (V_DC+). As a positive sampling resistor, sampling resistor R1 is used to collect the voltage signal at the DC bus's positive pole. Sampling resistor R1 ensures that the V_DC+ voltage signal is proportional to the DC bus voltage, accurately reflecting the bus's positive voltage. Sampling resistor R2 is connected between the DC bus's negative pole (DC-) and the voltage sampling point (V_DC-). As a negative sampling resistor, sampling resistor R2 is used to collect the voltage signal at the DC bus's negative pole.

[0141] The voltage sampling device further includes an operational amplifier circuit. The operational amplifier circuit includes:

[0142] There are two filter inductors L1. One end of one filter inductor L1 is connected to the voltage sampling point V_DC+. The other end of the filter inductor L1 is connected to the voltage sampling point V_DC-. The two filter inductors L1 are used to suppress high-frequency noise in the positive and negative voltage signals.

[0143] The operational amplifier U1 has an input end connected to the other end of the filter inductor L1 and is used to process the positive voltage signal and the negative voltage signal.

[0144] The LC filter network, connected in parallel with operational amplifier U1, filters the positive and negative voltage signals. The operational amplifier is the core component of the circuit. Its inputs receive signals from V_DC+ and V_DC-, and its output provides an amplified signal (AD) to the controller.

[0145] The LC filter network includes:

[0146] The filter capacitor C2 is used to filter high-frequency noise and provide a bypass path so that the high-frequency signal is bypassed through the capacitor.

[0147] The filter inductor L2 works together with the filter capacitor C2 to further suppress high-frequency signals so that the amplifier can process cleaner voltage signals.

[0148] The current sampling device A1 is used to collect the current signal of the DC bus.

[0149] A controller is connected to the relay K1, the variable resistor Rn, the voltage sampling device, and the current sampling device A1. The controller is capable of calculating the DC power of the DC bus based on the voltage and current signals, and adjusting the resistance value of the variable resistor based on changes in the DC power, so that when the DC power reaches a maximum value, the sum of the losses of the DC ripple suppression circuit and the main circuit is minimized.

[0150] This embodiment provides a control method for a DC ripple suppression circuit. The DC ripple suppression circuit can be selectively connected to a DC bus, which is used to power a main circuit.

[0151] The method may be executed by a controller, such as Figure 5 As shown, the method may include:

[0152] Step S104: When the DC ripple suppression circuit is connected to the DC bus, the voltage signal and the current signal of the current DC bus are collected.

[0153] In this embodiment, the acquisition process can be represented as the process of real-time monitoring and acquisition of the DC bus voltage and current signals by a controller. It is understood that the controller is connected to a voltage sampling device and a current sampling device, and can acquire the voltage signals at the positive and negative poles of the DC bus, as well as the current signal passing through the DC bus, through the voltage sampling device and the current sampling device. The acquired analog signals are processed by an ADC preset in the controller and converted into digital signals.

[0154] In this embodiment, the acquisition action may be a dynamic and continuous operation, and the controller continuously monitors the voltage and current changes of the DC bus during operation to reflect the current status in a timely manner.

[0155] Step S106: Based on the voltage signal and / or current signal, determine whether a preset condition is met.

[0156] In this embodiment, the preset condition may be that the fluctuation amplitude of the current voltage signal needs to meet a first voltage fluctuation amplitude threshold.

[0157] Specifically, the first voltage fluctuation amplitude threshold indicates that when the fluctuation amplitude of the voltage signal of the DC power system meets the first voltage fluctuation amplitude threshold, the ripple voltage of the DC power system is basically resolved, and the controller can be triggered to perform the next optimization operation. For example, the controller can be triggered to adjust the variable resistor to the optimal variable resistance value. This ensures that when the DC power reaches the maximum value, the sum of the loss of the DC ripple suppression circuit and the loss of the main circuit is minimized. Correspondingly, when the fluctuation amplitude of the voltage signal of the DC power system fails to meet the first voltage fluctuation amplitude threshold, it indicates that the voltage fluctuation amplitude of the current DC power system is large, and it is necessary to wait for the DC ripple suppression circuit to suppress the voltage fluctuation in the DC bus or increase the resistance value of the variable resistor in the DC ripple suppression circuit so that the DC ripple suppression circuit can further suppress the voltage fluctuation in the DC bus.

[0158] In other words, the first voltage fluctuation amplitude threshold can represent the maximum allowable fluctuation amplitude of the DC power system's voltage signal under normal operating conditions. This first voltage fluctuation amplitude threshold can be pre-set through experiments, simulations, or standard specifications and can be used to assess the impact of voltage fluctuations on system performance. When the fluctuation amplitude of the DC power system's voltage signal meets this threshold, it indicates that the voltage fluctuation is within an acceptable range and the system can operate safely and stably.

[0159] In this embodiment, the preset condition may be that the fluctuation amplitude of the current signal must meet a first current fluctuation amplitude threshold. The first current fluctuation amplitude threshold may represent the maximum fluctuation amplitude allowed for the current signal of the DC power system under normal operating conditions. Similarly, the first current fluctuation amplitude threshold may also be pre-set through experiments, simulations, or standard specifications. When the fluctuation amplitude of the current signal of the DC power system meets this threshold, it indicates that the system current fluctuation is within a reasonable range and can ensure the normal operation of the load equipment.

[0160] In this embodiment, the preset condition may also be that the current voltage signal fluctuation amplitude must meet a first voltage fluctuation amplitude threshold, and the current current signal fluctuation amplitude must meet a first current fluctuation amplitude threshold. In some cases, the preset condition may require both the current voltage signal to meet the first voltage fluctuation amplitude threshold and the current current signal to meet the first current fluctuation amplitude threshold. This combined condition is intended to ensure that the DC power system is stable in both voltage and current, optimizing the decision-making basis for circuit control.

[0161] Step S108: When the preset conditions are met, determine the current DC power.

[0162] The determination of the current DC power may be expressed as multiplying the collected voltage signal and current signal to obtain the DC power.

[0163] As you can understand, the determined DC power value is used in subsequent control decisions. For example, the controller will use the current power value to determine whether to adjust the variable resistor to optimize the operation of the DC ripple suppression circuit. Because the voltage and current in the DC power system fluctuate with load changes, the real-time calculated DC power also changes dynamically. The controller continuously monitors changes in voltage and current to continuously update the power value.

[0164] In one specific embodiment, the controller can extract the current positive and negative voltage signals and calculate the effective voltage value of the DC bus. The effective voltage value can be the difference between the positive and negative voltages. The current signal is obtained by the current sampling device. The obtained voltage and current signals are substituted into the DC power calculation formula to obtain the current DC power.

[0165] Step S110: adjusting the resistance value of the variable resistor in the DC ripple suppression circuit so that the DC power reaches a maximum value, thereby minimizing the sum of the loss of the DC ripple suppression circuit and the loss of the main circuit.

[0166] In this embodiment, the adjustment action may be represented by the controller issuing an instruction to the variable resistor, thereby adjusting the resistance value of the variable resistor in the DC ripple suppression circuit through the instruction, for example, increasing the resistance value of the variable resistor or decreasing the resistance value of the variable resistor.

[0167] In this embodiment, the maximum value may be a preset maximum value. The preset maximum value may be a fixed value. The preset maximum value may be obtained through experiments or simulation calculations. For example, by conducting multiple experiments on the DC power system and adjusting parameters such as the variable resistor and absorption capacitor in the system, the power peak of the system under different working conditions can be found. After recording these peak powers, these values ​​can be stored in the controller as preset maximum values. The voltage fluctuations and current changes of the DC bus can be simulated by performing circuit simulation on the entire circuit. The maximum power output point of the system can be found through simulation tools and stored in the controller as a preset value.

[0168] Specifically, the maximum value can be a maximum value obtained through real-time calculation. This maximum value obtained through real-time calculation is adjusted by the controller during operation based on the collected voltage and current signals through dynamic feedback and optimization algorithms until the DC power is maximized. Therefore, in this case, the maximum value is not fixed, but changes continuously according to the real-time operation of the DC power system. More specifically, the controller can continuously collect the voltage and current of the DC bus through a voltage sampling device and a current sampling device to calculate the current DC power. The controller can change the current in the absorption circuit by adjusting the resistance of the variable resistor, thereby affecting the voltage fluctuation of the DC bus. The controller can detect the change in DC power after each adjustment through closed-loop feedback control. If the DC power increases, the variable resistor is further adjusted. If the DC power decreases, the adjustment is made in the opposite direction until the DC power reaches its peak value.

[0169] In a specific embodiment, step S110 may include:

[0170] The DC power value determined in step S108 serves as the starting reference point for adjustment. The controller issues a command to the variable resistor to begin adjusting its resistance value. Initial adjustment may involve slightly increasing or decreasing the resistance value to observe the effect on the DC power. The controller can control the resistance value of a variable resistor device, such as a MOSFET, IGBT, or programmable resistor, using a PWM signal or other control signal. The controller again collects the adjusted voltage and current signals and recalculates the current DC power value. The controller compares the adjusted DC power value with the initial power value before adjustment. If the power increases, the current variable resistor adjustment direction is correct, and the controller continues to adjust the resistance value in the same direction. If the power decreases, the current adjustment direction is incorrect, and the controller changes the adjustment direction and adjusts the resistance value in the opposite direction. After each adjustment of the variable resistor, the controller collects the voltage and current signals in real time and recalculates the DC power value. Through this feedback loop, the controller can determine which resistance value corresponds to the maximum DC power. It will be understood that this process is iterative, with the controller gradually approaching the optimal resistance value by repeatedly adjusting the resistance value, calculating the power, and comparing the power changes. The controller continues iterative adjustments until it finds a point where the DC power no longer increases, regardless of whether the resistance value is increased or decreased. When this occurs, the controller has found the maximum DC power value, and the variable resistor value at this point is the optimal value. For example, the controller records the DC power values ​​after several consecutive adjustments. When these values ​​no longer change significantly, it is considered to have reached the maximum power point. Alternatively, after a certain adjustment, the power begins to decrease or remain constant regardless of further increasing or decreasing the resistance, indicating that the power has reached its maximum value. When the DC power reaches its maximum value, the system is operating optimally, and the sum of the losses in the DC ripple suppression circuit and the main circuit is minimized.

[0171] The DC ripple suppression circuit control method of this embodiment effectively suppresses DC ripple by collecting voltage and current signals from the DC bus and determining the current state based on these signals, thereby optimizing the DC power output. This method ensures that when connected to the DC bus, the resistance value of the variable resistor can be dynamically adjusted to maximize the DC power, thereby effectively reducing circuit losses and improving energy efficiency. Furthermore, by monitoring voltage and current, the control method can respond to changes in a timely manner, ensuring the stability and reliability of the device, thereby improving the performance of the DC ripple suppression circuit under various operating conditions.

[0172] In some cases, if a DC ripple suppression circuit is connected to the DC bus for a long time, regardless of whether ripple current is present, it will generate unnecessary energy loss and reduce the overall efficiency of the system. In related technologies, DC ripple suppression circuits are usually always connected to the DC bus, causing the circuit to consume power even when the ripple current is small or non-existent, increasing ineffective losses. In addition, continuous connection may also cause unnecessary capacitor charging and discharging processes, affecting the service life of circuit components.

[0173] Therefore, in some embodiments, Figure 6 As shown, the control method further includes:

[0174] Step S100: Determine whether the DC ripple suppression circuit needs to be connected to the DC bus.

[0175] In this embodiment, the controller can calculate the fluctuation amplitudes of the voltage and current signals and compare the calculated voltage and current fluctuation amplitudes with pre-set thresholds. When the voltage signal fluctuation amplitude exceeds the set threshold (e.g., a first voltage fluctuation amplitude threshold), it indicates that a large voltage ripple exists in the system. When the current fluctuation amplitude exceeds the set threshold (e.g., a first current fluctuation amplitude threshold), it indicates that a large ripple current exists in the system.

[0176] If the voltage or current fluctuation amplitude exceeds a threshold, the controller determines that a DC ripple suppression circuit needs to be connected to the DC bus to suppress voltage and current fluctuations. If the voltage and current fluctuation amplitudes are both below the threshold, the controller determines that the suppression circuit is not necessary and remains disconnected to avoid unnecessary energy consumption.

[0177] Step S102: When it is determined that the DC ripple suppression circuit needs to be connected to the DC bus, the switch device is controlled to close to connect the DC ripple suppression circuit to the DC bus, so that the DC ripple suppression circuit absorbs the ripple current in the DC bus.

[0178] When it is determined that the DC ripple suppression circuit needs to be connected, the controller sends a signal to trigger the switching device to close, thereby connecting the suppression circuit to the DC bus.

[0179] This embodiment introduces steps S100 and S102 to determine whether a DC ripple suppression circuit needs to be connected and, when necessary, control the switching device to close, selectively connecting the circuit to the DC bus. This allows the circuit to be connected when ripple suppression is needed and disconnected when ripple is not, significantly reducing system energy loss and extending component life.

[0180] In some cases, the fluctuations in voltage and current signals in existing DC power systems can be unstable. In particular, when DC ripple is present, the system's voltage and current fluctuations can increase, leading to reduced equipment efficiency and increased power loss. However, in related technologies, many systems are unable to effectively monitor the specific amplitude of these fluctuations, making it difficult to determine whether ripple suppression measures are needed. In particular, when the voltage or current fluctuation amplitude is not precisely controlled, the system may continue to engage the ripple suppression circuit unnecessarily, increasing unnecessary power loss.

[0181] Therefore, if Figure 7 As shown, in some embodiments, the step of determining whether a preset condition is met based on the voltage signal and / or the current signal includes:

[0182] Step S1062: Determine whether the fluctuation amplitude of the voltage signal meets a preset first voltage fluctuation amplitude threshold, and / or determine whether the fluctuation amplitude of the current signal of the DC bus meets a preset first current fluctuation amplitude threshold.

[0183] In this embodiment, it is only necessary to determine whether the fluctuation amplitude of the voltage signal meets a preset first voltage fluctuation amplitude threshold.

[0184] In this embodiment, it is only necessary to determine whether the fluctuation amplitude of the current signal of the DC bus satisfies a preset first current fluctuation amplitude threshold.

[0185] In this embodiment, it is also possible to simultaneously determine whether the fluctuation amplitude of the voltage signal meets a preset first voltage fluctuation amplitude threshold and whether the fluctuation amplitude of the current signal of the DC bus meets a preset first current fluctuation amplitude threshold.

[0186] Step S1064: When the preset first voltage fluctuation amplitude threshold and / or the first current fluctuation amplitude threshold are met, it is determined that the preset condition is met.

[0187] This embodiment uses steps S1062 and S1064 to determine whether the voltage and / or current fluctuation amplitude exceeds a preset threshold, and uses this as a judgment criterion to determine whether to proceed to the next step. This method can accurately identify actual fluctuations in the system, thereby avoiding unnecessary energy consumption and optimizing the overall efficiency of the system.

[0188] In some cases, while adjusting the variable resistor's resistance value can maximize DC power, the ripple suppression effect may not fully meet the requirements of certain high-precision applications. For example, in scenarios with strict requirements for DC bus ripple voltage and current, the system may still experience large voltage and current fluctuations.

[0189] Therefore, in some embodiments, the control method further comprises:

[0190] Step S112: When the DC power reaches a maximum value, the resistance value of the variable resistor is reduced based on the current resistance value of the variable resistor, thereby improving the DC ripple suppression circuit's ability to absorb the ripple current in the DC bus.

[0191] Step S114: Determine whether the fluctuation amplitude of the voltage signal satisfies a preset second voltage fluctuation amplitude threshold, and / or determine whether the fluctuation amplitude of the current signal of the DC bus satisfies a preset second current fluctuation amplitude threshold; wherein, the second voltage fluctuation amplitude threshold is smaller than the first voltage fluctuation amplitude threshold, and the second current fluctuation amplitude threshold is smaller than the first current fluctuation amplitude threshold.

[0192] In this embodiment, the second voltage fluctuation amplitude threshold can be expressed as a threshold that is smaller than the first voltage fluctuation amplitude threshold. This threshold is used to further accurately control the fluctuation of the DC bus voltage to ensure that the voltage fluctuation amplitude is within a lower range. This threshold is used in high-precision scenarios. When the voltage signal fluctuation amplitude of the DC bus is lower than this threshold, it indicates that the voltage fluctuation in the system is small enough to meet more stringent voltage stability requirements. Compared with the first voltage fluctuation amplitude threshold, the second voltage fluctuation amplitude threshold requires smaller voltage fluctuations to ensure higher voltage stability and system reliability. When the voltage fluctuation amplitude does not meet this threshold, the controller will continue to adjust the variable resistance to enhance the suppression effect until the fluctuation amplitude drops below the threshold.

[0193] In this embodiment, the second current fluctuation amplitude threshold can be expressed as a threshold that is smaller than the first current fluctuation amplitude threshold. This threshold is used to further reduce the current fluctuation amplitude in the DC bus to ensure that the current maintains a smaller fluctuation range under high precision requirements. This threshold is used to ensure that the current fluctuation amplitude is within a smaller range when the current fluctuation in the DC bus must achieve higher precision. When the current signal fluctuation amplitude of the DC bus is less than the second current fluctuation amplitude threshold, it indicates that the current fluctuation in the system meets more precise control requirements and the suppression effect reaches an ideal state. If the current fluctuation does not reach this threshold, the controller will further suppress the fluctuation by continuing to adjust the variable resistor until the higher precision standard is met.

[0194] Step S116: When a preset second voltage fluctuation amplitude threshold and / or a preset second current fluctuation amplitude threshold are met, stop reducing the resistance value of the variable resistor.

[0195] In this implementation, after the DC power reaches its maximum value, the resistance of the variable resistor is further reduced, thereby improving the DC ripple suppression circuit's ability to absorb ripple current in the DC bus, meeting the need for higher-precision ripple suppression. By setting a second voltage fluctuation amplitude threshold and a second current fluctuation amplitude threshold (both lower than the first threshold), this implementation enables more stringent monitoring of voltage and current fluctuations in the system, ensuring more thorough ripple suppression while meeting high-precision requirements. This not only improves system stability and reliability but also optimizes overall performance and reduces the impact of residual fluctuations on equipment in certain application scenarios with higher requirements for voltage and current fluctuations.

[0196] In some cases, existing DC ripple suppression circuits are unable to efficiently find the system's optimal operating point. Even when adjusting the resistance of a variable resistor to control DC power, the DC power often fails to reach its optimal value due to insensitive power changes or imprecise adjustment steps. This can lead to increased energy consumption, suboptimal suppression, and even failure to minimize losses. The related art lacks an efficient dynamic adjustment method that can quickly and accurately find the maximum DC power value and minimize losses during variable resistor adjustment.

[0197] In some embodiments, the step of adjusting the resistance value of the variable resistor in the DC ripple suppression circuit so that the DC power reaches a maximum value, thereby minimizing the sum of the loss of the DC ripple suppression circuit and the loss of the main circuit, includes:

[0198] Step S1102: continuously increasing or decreasing the resistance value of the variable resistor in the DC ripple suppression circuit so that the DC power continuously changes.

[0199] Step S1104: When the DC power does not change regardless of whether the resistance value of the variable resistor in the DC ripple suppression circuit is increased or decreased, the DC power at this time is taken as the maximum value, and the resistance value of the variable resistor in the DC ripple suppression circuit is stopped from being adjusted.

[0200] In this embodiment, by continuously adjusting the resistance of the variable resistor in the DC ripple suppression circuit, the controller can monitor changes in DC power in real time and accurately find the maximum DC power. When the power no longer changes with the resistance value, adjustment ceases, ensuring that the system operates at the optimal power point. This process effectively reduces unnecessary energy loss, minimizing the sum of the losses in the DC ripple suppression circuit and the main circuit. It also avoids the problem of insufficient DC power optimization caused by improper adjustment in related technologies, improving overall efficiency and reliability.

[0201] In some cases, DC ripple suppression circuits can easily fall into a local optimum when adjusting the variable resistor, preventing the DC power from reaching its global optimum. This local optimum is often caused by an inflexible adjustment strategy or an imperfect algorithm, leading to the system misjudging power peaks. This ultimately prevents the circuit from maximizing energy efficiency and minimizing losses. The prior art lacks an optimization algorithm that can effectively avoid this local optimum and ensure global optimal performance.

[0202] In some embodiments, the step of adjusting the resistance value of the variable resistor in the DC ripple suppression circuit so that the DC power reaches a maximum value, thereby minimizing the sum of the loss of the DC ripple suppression circuit and the loss of the main circuit, includes:

[0203] Based on a preset optimization algorithm, the resistance value of the variable resistor in the DC ripple suppression circuit is continuously adjusted so that the DC power continuously changes; wherein, the preset optimization algorithm is used in the process of adjusting the resistance value of the variable resistor to avoid the local optimal value of the maximum value of the DC power and to find the global optimal value of the maximum value of the DC power.

[0204] In this embodiment, the preset optimization algorithm may be a gradient descent algorithm. Specifically, the controller calculates the gradient of the current DC power relative to the resistance value. Based on the direction of the gradient, the controller adjusts the resistance value of the variable resistor in a direction that increases the DC power. When the gradient approaches zero (i.e., the power no longer changes), the controller stops adjusting and deems the global optimal power value to have been found.

[0205] In this embodiment, the preset optimization algorithm may be a particle swarm optimization algorithm. Specifically, during initialization, multiple particles are initialized, each representing a resistance value. The DC power corresponding to each particle is calculated, and its historical optimal power value is recorded. All particles adjust their resistance values ​​based on their individual and group optimal positions, and the next round of calculations is performed. This process is repeated until all particles converge on the global optimal power point.

[0206] In this embodiment, the preset optimization algorithm may be a simulated annealing algorithm. Specifically, the controller starts with an initial resistance value and calculates the current DC power. Each time, a new resistance value is randomly selected and the new DC power is calculated. If the new DC power is greater, the resistance value is accepted; if the power is less, a probability-based decision is made whether to accept the new value. As the number of iterations increases, the random perturbations decrease, gradually converging to the global optimal power.

[0207] When the DC power reaches a global optimal value, the adjustment of the resistance value of the variable resistor in the DC ripple suppression circuit is stopped.

[0208] In this implementation, by introducing a preset optimization algorithm, the DC power can be effectively prevented from being trapped in a local optimum during adjustment. The preset optimization algorithm enables continuous and dynamic adjustment of the variable resistor's resistance value, ensuring that the controller can fully search for the global maximum value of the DC power. When the global optimal power point is reached, the controller stops adjustment, minimizing the sum of the losses in the DC ripple suppression circuit and the main circuit. This approach improves the overall energy efficiency of the system, ensures precise power optimization, and reduces unnecessary energy consumption, thereby enhancing system reliability and stability.

[0209] In some embodiments, the control method further comprises:

[0210] When the preset condition is not met, the resistance value of the variable resistor in the DC ripple suppression circuit is reduced.

[0211] In this embodiment, when preset conditions are not met, by reducing the resistance of the variable resistor, the current flow in the DC ripple suppression circuit can be increased, thereby enhancing its ability to absorb ripple current. Reducing the resistance value can more quickly and effectively suppress voltage or current fluctuations in the DC bus, especially in situations with large fluctuations or strong ripple, helping to improve the stability and performance of the DC power system. This ensures that the system can make timely adjustments when fluctuations exceed the preset range, thereby better controlling the ripple current, improving the overall efficiency of the system, and ensuring smooth operation.

[0212] According to an embodiment of the present invention, an electronic device is provided. Figure 10 The electronic device in this embodiment may include one or more of the following components: a processor, a network interface, a memory, a non-volatile memory, and one or more applications, wherein the one or more applications may be stored in the non-volatile memory and configured to be executed by one or more processors, and the one or more programs are configured to execute the method described in the aforementioned method embodiment.

[0213] According to an embodiment of the present invention, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a computer, the computer executes the method described in any of the above embodiments.

[0214] According to an embodiment of the present invention, a computer program product including instructions is provided. When the instructions are executed by a computer, the computer is caused to execute the method in any one of the above embodiments.

[0215] According to an embodiment of the present invention, a motor is provided, comprising a DC ripple suppression circuit as described above.

[0216] According to an embodiment of the present invention, an air conditioner is further provided, comprising the DC ripple suppression circuit as described above.

[0217] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in a sequence other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0218] Optionally, the specific examples in this embodiment may refer to the examples described in the above embodiments, and this embodiment will not be described in detail here.

[0219] The serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0220] In the above embodiments of the present application, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, please refer to the relevant description of other embodiments.

[0221] The above is only a preferred embodiment of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A DC ripple suppression circuit, characterized in that: The DC ripple suppression circuit can be selectively connected to a DC bus, which is used to power the main circuit. The DC ripple suppression circuit at least includes: a variable resistor, one end of which is connected to the positive bus of the DC bus, for adjusting the magnitude of the current in the DC ripple suppression circuit; an absorption capacitor, one end of which is connected to the other end of the variable resistor, and the other end of the absorption capacitor is connected to the negative bus of the DC bus, for absorbing DC ripple; A voltage sampling device and a current sampling device, which are used to collect voltage and current signals of the DC bus respectively; A controller, whose signal input end is connected to the voltage sampling device and the current sampling device respectively to obtain the voltage and current signals; and a signal output end of the controller is connected to the variable resistor.

2. The circuit according to claim 1, characterized in that The DC ripple suppression circuit further includes: A switch device has one end connected to the positive bus of the DC bus and the other end connected to one end of the variable resistor, and a control end of the switch device is connected to the controller.

3. The circuit according to claim 2, characterized in that The switching device is a relay.

4. The circuit according to claim 1, wherein: The controller is a microcontroller, a digital signal processor or a field programmable gate array.

5. The circuit according to claim 1, wherein: The DC ripple suppression circuit further includes: A discharge resistor is connected in parallel with the absorption capacitor and is used to provide a discharge path for the absorption capacitor after the absorption capacitor is charged, so that the absorption capacitor can be discharged in time during the subsequent ripple absorption process.

6. The circuit according to claim 1, wherein: The voltage sampling device comprises: A first voltage sampling device, one end of which is connected to the positive bus of the DC bus and is used to collect the positive voltage signal of the DC bus; a second voltage sampling device, one end of which is connected to the negative bus of the DC bus and is used to collect the negative voltage signal of the DC bus; An operational amplifier circuit, whose input end is respectively connected to the other end of the first voltage sampling device and the second voltage sampling device, and whose output end is connected to the controller, is used to process the received positive voltage signal and negative voltage signal and then input them into the controller.

7. The circuit according to claim 6, characterized in that The operational amplifier circuit comprises: a filter inductor, one end of which is connected to the other end of the first voltage sampling device and the other end of the second voltage sampling device, for suppressing high-frequency noise in the positive voltage signal and the negative voltage signal; an operational amplifier, the input end of which is connected to the other end of the filter inductor, and is used to process the positive voltage signal and the negative voltage signal; An LC filtering network is connected in parallel with the operational amplifier and is used to perform filtering processing on the positive voltage signal and the negative voltage signal.

8. The circuit according to claim 6, characterized in that The first voltage sampling device is a first sampling resistor, which is connected between the positive busbar of the DC bus and the first voltage sampling point; the second voltage sampling device is a second sampling resistor, which is connected between the negative busbar of the DC bus and the first voltage sampling point; wherein the first voltage sampling point and the second voltage sampling point are respectively connected to the input ends of the operational amplifier circuit.

9. A motor, characterized in that: The motor includes a DC ripple suppression circuit as described in any one of claims 1-8.

10. An air conditioner, characterized in that: The air conditioner includes a DC ripple suppression circuit as described in any one of claims 1-8.

Images