66 results about "Voltage optimisation" patented technology

The invention relates to a source-containing power distribution network multi-target collaborative voltage optimization control method based on an FACMAC algorithm, and belongs to the technical field of photovoltaic inversion control. According to the technical scheme, a power distribution network physical system is composed of a plurality of feeder lines, a transformer, a line and a plurality of grid-connected photovoltaic inverters, and each inverter can measure operation information such as local voltage and current in real time; the data acquisition and communication system is used for acquiring node operation data and realizing low-delay communication; the multi-agent reinforcement learning control system is composed of a plurality of distributed agents and factorization centralized Critic modules, and whole-network voltage optimization decision can be carried out in training and execution stages. And the execution unit adjusts the reactive power output of the inverter in real time according to the control instruction. According to the method, the whole-network cooperative regulation and control capability is improved, the training efficiency bottleneck in a high-dimensional scene is relieved, the expression capability on a complex nonlinear coupling relationship is enhanced, and efficient, stable and extensible power distribution network voltage optimization control is realized.

The invention discloses a three-phase vehicle-mounted charger hierarchical control method and system based on a battery state, and the method comprises the steps: obtaining the battery state data of a vehicle-mounted power battery, the battery state data at least comprising a battery voltage and a battery charge state; determining a charging mode according to the battery voltage and / or the battery charge state; when the charging mode is a first charging mode, controlling the PFC converter to operate in a constant voltage output mode, and executing voltage following control on the bidirectional DC-DC converter based on the battery voltage; and when the charging mode is a second charging mode, executing voltage following control on the PFC converter based on the battery voltage, and controlling the bidirectional DC-DC converter to operate in a constant-frequency or constant-phase output mode at the same time. By setting hierarchical control strategies under different working conditions, the output voltage of the PFC converter is adaptively adjusted, the voltage regulation transformation ratio under different working conditions is optimized, the overall circuit structure is improved, and the charging efficiency of the vehicle-mounted charger within the full working condition range is improved.

The micro-grid multi-time scale voltage optimization method based on deep reinforcement learning comprises the steps of providing a multi-time scale collaborative optimization framework based on deep reinforcement learning for a voltage out-of-limit problem caused by distributed photovoltaic access in a micro-grid; an improved hierarchical DQN (HRL-Dueling DQN) algorithm is adopted to carry out long-time scale optimization control on discrete capacitor equipment, so that the voltage out-of-limit risk is reduced; and performing short-time scale fine adjustment on reactive output of the continuous photovoltaic inverter by using a depth deterministic strategy gradient (DDPG) algorithm to suppress voltage deviation. According to the micro-grid multi-time scale voltage optimization method based on deep reinforcement learning, the real-time performance and robustness of voltage optimization are improved, the voltage out-of-limit risk is effectively restrained, voltage fluctuation is finely adjusted, and reliable guarantee is provided for safe and stable operation of a micro-grid with new energy access.

The invention relates to the technical field of electric vehicle driving control, and particularly discloses a driving control system and method for intelligent transfer equipment. The driving control method is used for solving the driving control problems of large current tracking error, high torque ripple and noise vibration, unstable regeneration and poor low-speed micro-climbing and ramp restarting response caused by sampling and inverter time lag, parameter drift, bus fluctuation and degradation faults of a six-phase permanent magnet synchronous motor of intelligent transfer equipment under the complex working condition of a port. The system comprises an AT-AGV, a PMSM, a six-phase inverter, a DC bus, a controller and a planning module. Through midpoint sampling, two-beat equivalent time-delay modeling and limited deadbeat voltage optimization, and in combination with xy harmonic compensation, online parameter identification, three-section regeneration trajectory and fault-tolerant SVPWM, robust stability and high-efficiency recovery under low-overshoot rapid torque establishment, low ripple and low NVH, bus fluctuation and fault are realized; accurate current tracking and smooth traction are realized during micro-crawling and ramp restarting.

The invention belongs to the technical field of voltage optimization, and particularly relates to a reactive voltage optimization control method suitable for a large-scale new energy collection area, and the method comprises the steps: constructing a node power distribution network topology based on a power system simulation platform, and obtaining a training label; mapping the power distribution network into a graph structure containing nodes and edges; executing graph convolution operation through a graph neural network, extracting single-moment spatial topological features, and arranging the single-moment spatial topological features according to a time sequence to form a spatial topological feature sequence; performing spatial-temporal dynamic modeling on the spatial topological feature sequence by using an improved Mamba model, and outputting a spatial-temporal time sequence feature sequence; introducing an attention mechanism, and outputting a reactive power prediction value of each controllable device as a control instruction of power distribution network dispatching; and outputting a control instruction of actual power distribution network dispatching by using the trained graph neural network and the improved Mama model. According to the invention, under the condition of ensuring voltage safety and reactive constraint, the voltage out-of-limit quantity is reduced, and the voltage qualification rate is improved.

The invention discloses a low-carbon demand response and partition hierarchical scheduling system and method based on cloud side-end collaboration, and belongs to the technical field of carbon emission reduction resource response capability modeling and interaction mechanisms, and the system comprises a physical layer, a terminal layer and a platform layer. According to the method, firstly, a node carbon potential modeling method under a dynamic carbon emission factor is researched, multi-type flexible resource models of an electric vehicle, an air conditioner load, an electric hydrogen load, energy storage and the like are constructed, a multi-time-scale multi-element resource response capability evaluation method is formed, and a multi-target demand response interaction mechanism and a cluster regulation and control method considering low carbon and high reliability are provided; secondly, researching a supply and demand cooperation partition interaction low-carbon regulation and control technology in a steady state, and proposing a hierarchical partition cooperation active scheduling and reactive voltage optimization method; and finally, realizing low-carbon demand response and partitioned hierarchical scheduling of different dimensions by relying on a cloud side regulation and control framework.

The invention discloses a short-time voltage fluctuation suppression method, device and equipment based on partition fluctuation evaluation, and relates to the technical field of power system control. The method comprises the following steps: under a minute-level time scale, taking the comprehensive minimization of active power loss, voltage fluctuation in adjacent time periods and reactive power regulation cost as a target, constructing a multi-period reactive power voltage optimization control model, and obtaining a reference voltage and a reference reactive power control quantity; a power system is partitioned through a modularity-based reactive voltage control robust partitioning algorithm, and influence areas which are mainly influenced by new energy fluctuation are identified on the basis of partitioning. And constructing a partition fluctuation evaluation index and setting a partition optimization event triggering mechanism. And under a short-time scale, constructing a subarea reactive voltage optimization control model based on quadratic programming by utilizing a subarea space decoupling technology, and executing subarea coordination optimization. And correcting the partition reactive voltage optimization control model through a model correction method based on multiple linear regression.

The invention discloses a multi-reactive-power-source static and dynamic optimization control method and system based on source-network cooperation, and the method comprises the steps: S1, building and solving a unified optimization model for fusing multiple types of reactive power sources at a power grid side and a power supply side based on ultra-short-term prediction data, and generating a switching plan, a reference curve and a voltage optimization target interval in a future time period; s2, performing simulation check on the optimization plan by using a power grid digital twin model, and if a transient voltage safety standard is violated, triggering re-optimization taking transient safety as a constraint; s3, based on the optimization target and real-time measurement, a tracking adjustment mode or an emergency cooperative control mode is adaptively executed according to the disturbance level; and S4, equipment execution and feedback updating. Through static and dynamic closed-loop coordination and source network resource global optimization, the problems of static and dynamic separation and insufficient source network coordination in traditional control are solved, and the economical efficiency, the safety and the adaptive capacity of the high-proportion renewable energy power grid are remarkably improved.

The present application relates to a multi-stage coordinated voltage optimization method for a power distribution network optical storage system, which divides the voltage regulation strategy into three stages: 1) using an analytical method for local reactive power compensation of a photovoltaic inverter; 2) selecting the reactive power output of the photovoltaic inverter as a consistency variable based on filter consistency, and performing distributed reactive power regulation of the photovoltaic inverter; 3) selecting the state of charge variation of the energy storage system as a consistency variable based on filter consistency, and performing distributed active power regulation of the energy storage system; this method can fully utilize the voltage regulation resources of the distributed photovoltaic-energy storage system to control the voltage, while solving the voltage out-of-limit problem, and as much as possible reducing the total active power output of the photovoltaic system due to participation in voltage control, and reducing the overall voltage regulation cost of the energy storage system, and at the same time, this method can well adapt to the normal changes of the information-physical topology of the power distribution system, and has better voltage regulation effect and adaptability compared with the traditional single control mode single-stage voltage regulation strategy.

The invention provides a power distribution network reactive voltage optimization method based on mathematical analysis, and relates to the technical field of power distribution network control, and the method comprises the steps: S1, building a control model of a distributed active power distribution network reactive power compensation device according to a physical model and control characteristics of the distributed active power distribution network reactive power compensation device; s2, establishing a multi-optimization objective function which takes the minimum network loss as a core and takes voltage quality into account, and establishing operation constraint conditions; s3, based on the obstacle function conversion constraint and gradient / Hessian matrix optimization, designing a solving algorithm model; and S4, integrating the control model, the multi-objective optimization function and the operation constraint condition into an active power distribution network reactive voltage coordination control optimization model, calling a solution algorithm model for solution, and outputting an optimization control scheme of the reactive power compensation device. According to the scheme, the problems that a traditional distribution network optimization model does not fully fuse the characteristics of the distributed active reactive power compensation device, and a multi-dimensional target and complete constraint are not designed for the active power distribution network can be solved.

A supply voltage may be set using a local voltage regulator, such as a Digital Linear Voltage Regulators (DLVR). A DLVR may include a compensator, and the performance of the compensator may be affected by a dropout (DO) voltage. To improve the performance of a compensator, a number of compensator calculations may be pre-calculated to reduce the complexity of remaining real-time computations and enable compensator calculations to be completed within a single DLVR clock cycle. A DLVR may include a sense filter, and the DLVR transfer function (TF) may be modified using dynamic shaping of open loop gain and pole locations of a sense filter. The DO range associated with the DLVR TF may be changed according to a monitored DO(t) to reduce the sensitivity of a domain VMIN on dropout, which reduces power consumption, increases performance, and enables simplification of test flows.

The application discloses a kind of multi-energy distribution network voltage control methods, comprising the following steps, define local voltage control rule;Analysis distributed power output causes voltage fluctuation upper and lower limit;Build global voltage control function;Algorithm is solved to objective function, the local voltage control rule is acquisition control point voltage u, determine whether to satisfy the following constraint, set the reactive power output of voltage compensation device.The multi-energy distribution network voltage control method, considering the uncertainty fluctuation of distributed power supply, improve the accuracy of voltage fluctuation analysis, formulate the localized voltage adjustment rule and global voltage optimization function, realize passive control and active control combination, reduce fluctuation rate, using interval number to express the uncertainty of distributed power supply, less computing resource demand, control reaction speed is fast.

A GCIB apparatus that can change the energy of ions to be irradiated onto a substrate without changing the electrode arrangement of the GCIB apparatus that have an extraction electrode arrangement optimized for a specific voltage or a permanent magnet type magnet that effectively removes singly charged monomer ions at that voltage, or the magnetic field strength of the permanent magnet type magnet. A separated high voltage power supply that generates a positive or negative high voltage in addition to the first high voltage power supply, the second high voltage power supply and the third high voltage power supply, and a separated high voltage application circuit that applies a positive or a negative separated high voltage supplied from the separated high voltage power supply to the ground electrode of the extraction electrode and the ground electrode portions of the one or more electrostatic lenses.

This application relates to the field of power system technology, and in particular to a distributed optimization method for reactive power and voltage in a multi-zone flexible interconnected AC / DC hybrid distribution network based on cluster partitioning. By constructing distributed optimization models for reactive power and voltage within and between clusters, an improved particle swarm optimization algorithm (PSO) is used to enhance the global search capability of the model. Furthermore, the advantages of the alternating direction multiplier method (ADMM) for distributed solving are combined to improve solution efficiency and effectiveness, thereby effectively optimizing the reactive power and voltage of a multi-zone flexible interconnected AC / DC hybrid distribution network with a high proportion of distributed renewable energy. The aim is to solve the problem of reactive power and voltage optimization in such a network.

This invention discloses a hierarchical control method and system for a three-phase on-board charger based on battery state. The method includes: acquiring battery state data of the on-board power battery, the battery state data including at least battery voltage and battery state of charge; determining a charging mode based on the battery voltage and / or battery state of charge; controlling the PFC converter to operate in a constant voltage output mode when the charging mode is a first charging mode, while simultaneously performing voltage following control on the bidirectional DC-DC converter based on the battery voltage; and performing voltage following control on the PFC converter based on the battery voltage when the charging mode is a second charging mode, while simultaneously controlling the bidirectional DC-DC converter to operate in a constant frequency or constant phase output mode. This invention adaptively adjusts the output voltage of the PFC converter by setting hierarchical control strategies under different operating conditions, optimizes the voltage regulation ratio under different operating conditions, improves the overall circuit structure, and enhances the charging efficiency of the on-board charger across the entire operating range.

The application discloses a flexible on-load voltage regulating transformer multi-target cooperative control system and method based on hour-level load prediction, which comprises the following steps: a node parameter acquisition module acquires electrical parameters of each node of a power distribution network; a load prediction module outputs a load prediction sequence in the future time; a multi-target optimization module generates an optimal control optimization strategy according to a cooperative optimization model; an upper prediction optimization layer makes an hour-level optimization decision on tap position and capacitor group switching; a lower real-time adjustment layer outputs a voltage dynamic compensation amount and generates a minute-level equipment adjustment instruction; and an execution module coordinates and controls flexible on-load voltage regulating transformer (FOLTC) tap switching, capacitor group switching and converter action, so that multi-target optimization of voltage deviation, reactive power compensation and equipment loss is realized. The application is suitable for voltage optimization, reactive power compensation and loss control in a conventional load fluctuation scenario of a power distribution network.

The invention provides a voltage optimization control method and system for a multi-branch power distribution network based on moment difference analysis, and relates to the field of power distribution network voltage optimization control research. The method comprises the following steps: acquiring basic data and operation data of all typical daily power distribution networks; the upper limit and the lower limit of the critical moment difference of the distribution line are calculated for the typical day, and the real-time moment difference of each feeder line is obtained; the branch where the node with the most serious voltage out-of-limit is located is selected as a trunk line, and the multi-branch power distribution network is simplified and equivalent to a trunk line power distribution network; determining the regulation and control direction of the moment difference; determining the moment difference sensitivity of all regulation and control resources; and classifying all regulation and control resources according to the regulation and control cost, sorting according to the classification result and the moment difference sensitivity, and sequentially carrying out moment difference regulation and control according to the regulation and control direction of the moment difference until the moment difference of the main line is recovered to a normal range. According to the invention, the voltage optimization control of the multi-branch power distribution network is realized in the most economical and effective manner.

This invention relates to the field of power grid sensitive node identification technology, and discloses a method, system, device, and medium for identifying sensitive nodes in distribution networks based on sensitivity thresholds and topological electrical characteristics. The method includes: constructing a distribution network simulation model, performing power flow calculations, and obtaining a reactive power sensitivity matrix; performing a dual-threshold initial screening on the reactive power sensitivity matrix to obtain a theoretical set of sensitive nodes, and performing a second screening based on topology and electrical characteristics to obtain a final set of sensitive nodes; performing reactive power compensation and control simulation on the final set of sensitive nodes to verify the voltage optimization effect. This invention identifies high-impact nodes from a sensitivity perspective, and then uses degree centrality and electrical distance to exclude terminal and isolated nodes, ensuring that the selected points simultaneously possess strong control capabilities and feasibility; after configuring reactive power compensation at sensitive nodes, it can improve the overall network voltage qualification rate, reduce voltage deviation, and reduce network losses, and effectively suppress overvoltage problems caused by high-penetration distributed power sources.

This invention relates to a multi-timescale reactive power optimization method for unbalanced distribution networks based on an improved Golden Jackal algorithm. First, the Golden Jackal optimization algorithm is improved by combining low-difference sequence generation and chaotic mapping traversal enhancement to improve population initialization, ensuring the traversal characteristics of the population in space. A hyperbolic tangent-power-law hybrid attenuation model is designed to maintain global exploration and enhance local development. A leadership dynamic weighting mechanism is proposed to enhance the guiding role of optimal individuals and avoid getting trapped in local optima. Considering the three-phase voltage imbalance of the distribution network and the discrete characteristics of regulating equipment, a day-ahead reactive power-voltage optimization model is established and solved using the improved Golden Jackal optimization algorithm. Using the equipment action scheme obtained from the day-ahead optimization as the basis for intraday optimization, an intraday reactive power-voltage optimization model for a three-phase unbalanced distribution network considering continuous equipment is established to regulate reactive power and voltage. The improved Golden Jackal optimization algorithm is then used to solve the model, thus completing the second stage of optimization.

The present application relates to a kind of flexible interconnection ac-dc power distribution network multilayer collaborative voltage optimization method, comprising: the topological model of the mixed power distribution network including alternating current network, direct current network and voltage source converter interconnection device is established;Using the model conversion method based on second-order cone relaxation and linearization, the topological model is converted, and linearized topological model is obtained;Linearized topological model is used as foundation, and the system-level voltage optimization model considering dynamic network reconfiguration and the equipment-level voltage source converter droop control optimization model are constructed;In day-ahead stage, system-level voltage optimization model is solved, and in day-ahead stage, based on the real-time measurement data of power grid, the active power reference value of voltage source converter in day-ahead decision strategy is corrected on-line by equipment-level voltage source converter droop control optimization model.The present application can solve the problem of voltage fluctuation and regulation lag.

The invention belongs to but not limited to the technical field of power system operation control, and discloses a low-voltage distribution network voltage optimal compensation method and system. According to the method, a voltage drop mathematical model containing active power and reactive power of a power compensation device is established, the phase and amplitude relation of head and tail end voltages before and after compensation is analyzed, an optimization function with the minimum compensation current as the target is constructed, and a voltage phase angle optimal solution enabling the target function to obtain the minimum value is determined through derivation. And the minimum compensation current and the minimum apparent compensation power required by the power compensation device are calculated. On the premise of ensuring the voltage compensation effect, the current output of the compensation device can be effectively reduced, the energy efficiency is improved, and the method is suitable for voltage optimization control of a power distribution network and a micro-grid.

The invention discloses a flexible energy storage-oriented power distribution network multi-time-scale collaborative voltage optimization regulation and control method and system, and relates to the technical field of power grid voltage optimization regulation and control, and the method comprises the steps: on the basis of the day-ahead photovoltaic and load prediction power, taking the minimum power loss and voltage deviation of a power distribution network as an optimization target; solving and obtaining day-ahead scheduling result data of the slow-action equipment by considering a scheduling strategy that a beam condition adopts a first duration as a scheduling period and a first preset duration as a time resolution; and performing optimization decision based on day-ahead scheduling result data on the basis of intra-day photovoltaic and load prediction power, and solving and obtaining scheduling plan node data of real-time action equipment to dynamically correct a day-ahead scheduling result by adopting a rolling optimization scheduling strategy in which a second duration is a scheduling period and a second preset duration is a time resolution. According to the method provided by the invention, the technical problem that the adaptability of a voltage regulation and control system to complex working conditions is insufficient in the prior art is solved.

A supply voltage may be set using a local voltage regulator, such as a Digital Linear Voltage Regulators (DLVR). A DLVR may include a compensator, and the performance of the compensator may be affected by a dropout (DO) voltage. To improve the performance of a compensator, a number of compensator calculations may be pre-calculated to reduce the complexity of remaining real-time computations and enable compensator calculations to be completed within a single DLVR clock cycle. A DLVR may include a sense filter, and the DLVR transfer function (TF) may be modified using dynamic shaping of open loop gain and pole locations of a sense filter. The DO range associated with the DLVR TF may be changed according to a monitored DO(t) to reduce the sensitivity of a domain VMIN on dropout, which reduces power consumption, increases performance, and enables simplification of test flows.

The embodiment of the present application provides a kind of line voltage regulating equipment.The equipment includes: control device, and multiple voltage regulating devices and multiple monitoring devices arranged in different line sections of distribution line;Specifically, each monitoring device is used to collect the real-time line data of the line section, and is sent to control device;Control device includes data analysis module, adjustment instruction generation module and first communication module;Each voltage regulating device is used to adjust the line parameter of the line section according to the received adjustment instruction, to realize the voltage optimization of line section.Through this line voltage regulating equipment, the voltage stability of each section of line can be realized, while local adjustment and network optimization are considered, and the flexibility and reliability of distribution network are improved.

This invention belongs to the field of voltage level control technology, specifically relating to a reactive power voltage level control method and device based on optimal control objectives. The steps include: acquiring actual data during the reactive power voltage control process; analyzing the correlation between voltage influence factors, reactive power control modes, and reactive power configuration, forming judgment indicators from a quantitative perspective, and completing reactive power voltage leveling; considering the operating cost of reactive power voltage control, the number of switching operations of capacitor banks and on-load tap-changing transformers, and line active power transmission losses, establishing a reactive power voltage optimization model based on optimal control objectives; dynamically adjusting the sub-objective weights of the reactive power voltage optimization model using game theory weighting according to the reactive power voltage leveling situation; and solving the reactive power voltage optimization model using the NSGA-II algorithm within a set time period to obtain the optimal solution of the reactive power voltage level control method based on optimal control objectives. This invention can achieve multi-level reactive power voltage control, stabilizing the voltage within a safe range.

The invention provides a power distribution network reactive voltage optimization method and device based on a multi-modal large model. The technical key points are as follows: constructing a multi-modal input data set; simplifying a power flow equation of the power distribution network, deducing a dense coefficient matrix, and fusing a multi-head attention mechanism to embed a power flow mechanism and topological information; the method comprises the following steps: constructing a sample in a system node data-system node text form, training an encoder by adopting a CLIP framework, and aligning the multi-modal information of the power distribution network to a unified semantic space through comparative learning; constructing a solvable optimization model, presetting a text template, generating a reasoning chain sample in combination with a dynamic numerical value filling mechanism, and internalizing reasoning logic by the solvable optimization model through two-stage knowledge migration training; and taking an Llama2 architecture as a base model, performing training in combination with the trained encoder and the thinking chain sample, inputting data, outputting a textual operation scheme, and analyzing the textual operation scheme into a numerical control strategy.

The invention provides a power distribution network master-slave game voltage optimization control method considering electrical hydrogen production assistance, and relates to the technical field of power distribution network voltage control. The method mainly comprises the steps of obtaining parameters of a power distribution network voltage control system; constructing a mathematical model of a main body participating in power distribution network voltage control; designing a power distribution network voltage control model based on a master-slave game; and a master-slave game model solving algorithm based on a genetic algorithm and a stochastic optimization algorithm is designed, benefit maximization of the leader and the follower is realized, and meanwhile, the voltage stability of the power distribution network is ensured. Through the master-slave game model designed by the invention, the benefit of the control main body of each party can be maximized, and meanwhile, the stability of the voltage of the power distribution network is ensured.

This invention discloses a hierarchical distributed voltage optimization method for AC / DC distribution networks based on the objective cascade analysis method. First, a steady-state model of the AC / DC distribution network is established, and the relevant power flow equation constraints are subjected to second-order cone relaxation and linearization to establish an easily solvable hierarchical optimization model. Second, based on the characteristics of the AC / DC distribution network, a three-layer distributed optimization architecture based on the objective cascade analysis method is proposed. Based on this, the Lagrange multiplier method is introduced to establish voltage optimization models for each level. Finally, based on power-voltage sensitivity, an alternating iterative and rolling optimization method is used to solve the model. This invention can effectively solve the voltage overshoot and fluctuation problems caused by backflow of power flow by coordinating flexible interconnection devices with wind, solar, and energy storage under hierarchical control.

The present application relates to the technical field of power system optimization, in particular to a transformer area voltage optimization method based on voltage sensitivity analysis, comprising: reading the distribution network equipment model and the mapping relationship between the distribution network feeder and the bus, then collecting and analyzing the historical voltage data of each transformer area and the historical voltage data of the bus, calculating the sensitivity of the bus voltage to the transformer area voltage, taking the highest overall voltage qualified rate of the 10kV bus power supply transformer area as the target, based on the sensitivity of the bus voltage to the transformer area voltage, calculating the 10kV bus optimization voltage according to the voltage distribution of the bus power supply transformer area; the present application calculates the sensitivity of the bus voltage to the transformer area voltage by analyzing the historical voltage data of the bus and the transformer area, thereby determining the optimization target of the 10kV bus voltage of the power transmission network; the method aims to realize the accurate and effective regulation of the transformer area voltage of the distribution network, thereby improving the overall level of the transformer area voltage qualified rate of the distribution network, and ultimately promoting the stable and reliable operation of the power system.

A consumer unit (fuse disc) assembly includes: a first housing containing circuitry containing a circuit breaker for distributing power from a main power source to branch circuits, and a second housing containing a circuit breaker for distributing the power from the main power source to the branch circuits; a voltage optimizer is housed within the second enclosure to reduce the voltage of the main power supply before the voltage of the main power supply is distributed to the one or more branch circuits. The first shell comprises an external retreating groove, and the second shell is located in the retreating groove and located behind the first shell.