30results about How to "Avoid the phenomenon of "big horses and small carts"" patented technology

The invention belongs to electric motor, especially relates to triphase capacitance double rotor cage electric motor with high starting torque and low running power, which is made up of a stator, a rotor and a shaft. The stator slot of the electric motor is embedded with tow sets of low harmony concentric triphase symmetric phase change double-layer windings, the compensation windings 3-1 is connected with a capacitance C in series, the electric motor double rotor cage arranges two types, one is casting aluminum alloy double rotor cage rotor, the second one is casting aluminum double rotor cage rotor, the double rotor cage rotor is low drain reactance, the work winding and the compensation winding of the stator are connected in parallel onto the triphase power, when starting, the motor outputs high starting torque and inputs low starting current, high starting factor; when the electric motor runs normally, it can output the low power, high efficiency, high power factor, high overloading ability, which is a small 'horse' but driving large car, it saves the energy, belongs to the high efficiency energy-saving electric motor.

The invention provides an energy-saving control method and system for an air-source heat pump system. The method comprises the following steps that S1, a building standard cooling and heating load prediction model is constructed; S2, building refinement partitioning is conducted according to the building standard cooling and heating load prediction model, a cooling and heating energy-using demanddynamic curve of all subzones of a building is generated, and the dynamic curve is updated once at intervals; and S3, an air-source heat pump unit and an indoor tail end thereof, a freezing water pump, a valve unit, a fan and a heat pump host respond to an instruction sent by a central host in time, and according to the energy-using demand dynamic curve and combination of a time delay caused by the adjustable segment length and fluid velocity, operation stages of the air-source heat pump system is divided into an equipment starting stage, a steady state operation stage and an equipment shutdown stage for staging control. The invention further comprises the energy-saving control system of the air-source heat pump system. The energy-saving control system has the advantages of being efficient, stable, free of pollution, low in energy consumption, significant in energy-saving effect and the like, and therefore the total energy efficiency of the system can be improved by 5% to 25% on the basis of the original system efficiency.

The invention discloses a dual-three-phase bisymmetric winding permanent-magnet brushless direct-current motor. In the dual-three-phase bisymmetric winding permanent-magnet brushless direct-current motor, two permanent-magnet brushless direct-current motors are designed to share a rotor and a stator: 1, the two permanent-magnet brushless direct-current motors are designed as a special structure which shares the rotor and the stator; and 2, a self-charging function is realized by using the double winding permanent-magnet brushless direct-current motors which drive an electric vehicle. Namely, one motor winding is operated with no load by utilizing a motor winding when a vehicle parks; and the other motor winding forms a generator to realize a charging function, so that the charging function is singly realized when the motor is not operated.

Provided are an energy-saving control method and system for a river water source heat pump system. The method comprises the following steps that S1, building standard cold and heat energy consumptionlarge data are built; S2, according to the building function, energy using time and load distribution difference, by combination with the building standard cold and heat energy consumption large data,building refinement partitioning is conducted, a cold and heat energy requirement dynamic curve of all subzones of a building is generated, and the dynamic curve is updated once at fixed intervals; and S3, according to the cold and heat energy requirement dynamic curve of the building, the large hysteresis quality and nonlinearity of an air conditioner system are considered, the river water source heat pump system is divided into an equipment starting stage, a steady-state operation stage and an equipment halt stage, and staged control is conducted; and the temperature changes of river waterare monitored in real time, and when the temperature difference of inlet and outlet water of a river water source heat pump unit exceeds the set value, corresponding water pumps are controlled in a variable-frequency mode, and the water flow is adjusted. The invention further discloses the energy-saving control system for the river water source heat pump system. The energy-saving control method and system for the river water source heat pump system have the advantages of being high in efficiency, stable, free of pollution, small in energy consumption, remarkable in energy-saving effect and thelike.

The invention discloses an air-conditioner refrigerating device and heat recovery method, which comprises the following parts: preheating plate heat-exchanger 1, volume heat-accumulating radiators 2, 3, water-hydrothermal pump 4, channel 9, channel pump 10, wherein the volume heat-accumulating supplement radiator 37 is composed by pipe connection within several controlling valves in the relating position. The heat recovery method comprises the following steps: sending the water at 37 deg.c in the refrigerating tower into the preheating plate heat-exchanger 1; preheating the tap water in the tap water radiator at 35 deg.c then injecting the heat-accumulating radiators 2 or 3; sending the water in heat-accumulating radiators 2 or 3 into heat pump condenser6 to heat at 50 deg.c approximately, which generates the domestic heat water and realizes the circulating heating. The heat-accumulating radiator 37 accumulates the heat at night. The device can adjust the operation condition of present central air-conditioner system cooling water group, which saves the energy.

The invention provides an energy-saving workover rig based on double metering pumps or motors. The energy-saving workover rig is composed of a small power machine, a large power machine, a gearbox, a roller, a small hydraulic pump, a large hydraulic pump, a hydraulic accumulator, the small metering hydraulic pump or motor, the large metering pump or motor, a torque coupler and the like. The small metering hydraulic pump or motor and the large metering pump or motor are respectively connected with a chain wheel of the torque coupler through clutches. In the lifting and dropping process of tubular columns, three force gears are configured, the tubular columns are lifted through different force gears according to different weights of the tubular columns needing lifting, and the power utilization rate of the power machines is increased; energy is recovered through different force gears according to different weights of the dropping tubular columns, and the energy recovery rate of gravitational potential energy of the tubular columns is increased; energy generated in the auxiliary operation period when the tubular columns are lifted by the power machines is stored by the hydraulic accumulator and is used in the tubular column lifting process, and the installed power of the power machines is reduced.

The invention provides a microwave drying method of wood veneers. The method comprises the stage of preprocessing, wherein the wood veneers to be measured are taken and cut to be of the preset size, the oven dry weight and the wet weight are detected, microwave drying is performed on the preset ventilation condition till the veneers reach the target weight, and the electric energy consumption value of the process is recorded to obtain the water extraction rate of the wood veneers; and the stage of production, wherein the electric quantity needed by microwave drying of the wood is obtained according to the water extraction rate and the wet weight of the wood obtained in the stage of preprocessing, the best drying time is determined according to the operation power of the microwave drying equipment and the electric quantity needed by microwave drying of the wood, and the raw wood materials of the batch are processed by adopting the best drying time. Under the certain ventilation condition, the linear relation between the wood water extraction rate and the microwave electric energy consumption value is built; and the microwave wood drying technology time quantified control is achieved, the microwave drying efficiency is greatly improved, and the drying quality and economic benefits are ensured.

The invention discloses a power device of a milling and planing machine, relating to the technical field of construction machinery manufacturing. The power device comprises a clutch connected with a milling and planing drum through transmission of a belt, and a hydraulic pump arranged on a transfer case output shaft, wherein the clutch is arranged on an output shaft at one end of a first power machine, a first fan is arranged on an output shaft at the other end of the first power machine, a first heat radiator is arranged close to the first fan, a transfer case is arranged on an output shaft at one end of a second power machine, a second fan is arranged on an output shaft at the other end of the second power machine, and a second heat radiator is arranged close to the second fan. Compared with the prior art, the power device has the advantage that the problems of large power consumption and high in manufacture cost of an engine of an existing road milling and planing machine can be solved.

The invention discloses a coupling automobile-mounted air conditioner refrigeration and heating system for a power battery pack. The coupling automobile-mounted air conditioner refrigeration and heating system comprises a frequency-conversion compressor, an air conditioner external unit, a first throttling structure, a second throttling structure, an air conditioner internal unit, a power batterypack heat exchanger, a four-way reversing valve, a first magnetic valve, a second magnetic valve, a third magnetic valve, a fourth magnetic valve, a fifth magnetic valve and a sixth magnetic valve. The coupling automobile-mounted air conditioner refrigeration and heating system adopts the technical scheme that one frequency-conversion compressor has two functions, and achieves multiple working modes by controlling conducting directions of different valves; in summer, the power battery pack heat exchanger is used for cooling the power battery pack, and the air conditioner internal unit conveyscold air into an automobile cabin; in winter, the power battery pack heat exchanger is used for preheating the power battery pack, and the air conditioner internal unit conveys hot air into the automobile cabin; the coupling automobile-mounted air conditioner refrigeration and heating system ensures that the power battery pack is in the optimum working temperature rapidly; and the driving requirement of a new-energy automobile under different climate working conditions is met.

Provided are an energy-saving control method and system for a sewage source heat pump system. The method comprises the following steps that S1, a building standard cold and heat load prediction modelis established; S2, refine building partition is carried out according to the building standard cold and heat load prediction model, a cold and heat energy consumption need dynamic curve of sub-areasof a building is generated, and the dynamic curve is updated one time at intervals; and S3, facilities of the sewage source heat pump system respond to a command issued by a central mainframe in time,the sewage source heat pump system is divided into the facility starting phase, the steady-state operation phase and the facility shutdown phase according to the energy consumption need dynamic curve, in the steady-state operation phase, whether the temperature difference of a water inlet and outlet of a sewage source heat pump unit is within the set temperature range or not is judged, if yes, running is carried out in the set temperature difference range, and if no, variable-frequency adjustment is carried out on a corresponding water pump. The energy-saving control method and system for thesewage source heat pump system have the advantages of being efficient, stable, free of pollution, small in energy consumption, remarkable in energy saving effect and the like.

A constant displacement pump / motor tandem type energy-saving workover rig is composed of a small power machine, a large power machine, a transmission, a drum, a small hydraulic pump, a large hydraulic pump, a hydraulic accumulator, a small constant displacement pump / motor and a large constant displacement pump / motor. The small constant displacement pump / motor and the large constant displacement pump / motor are coaxially connected to output power. In the period of auxiliary operation of pipe column lifting, the power machines drive the hydraulic pumps to charge oil into the hydraulic accumulator for storing energy; during pipe column lifting, the power machines drive pressure oil in the hydraulic pumps and the hydraulic accumulator to enter the constant displacement pump / motors to lift a pipe column. Therefore, power of the power machines is reduced greatly as compared with that of a conventional workover rig, and is only about one fourth of that of the conventional workover rig. When the pipe column is lowered, the pipe column is lowered into a well under the action of own gravity, meanwhile, the constant displacement pump / motors are driven to charge oil into the hydraulic accumulator, in other words, the gravitational potential energy of the pipe column is converted into pressure energy in the hydraulic accumulator to be stored, and accordingly energy recovery is realized.

The invention relates to a turbocharger hysteresis compensation device based on air compensation of an intake pipe. An independent compressor and a gas storage tank are additionally arranged on an original engine system. The compressor is connected with an output shaft of an engine through an electromagnetic clutch which is controlled through a controller. When pressure in the gas storage tank is lower than first set pressure, the controller controls the electromagnetic clutch to combine, and the compressor starts to work. When the pressure in the gas storage tank reaches second set pressure, the electromagnetic clutch is controlled to separate, and the compressor stops working. When the rotating speed of the engine is low, a turbocharger does not work, and a high-speed solenoid valve is controlled by the controller to directly supply high-pressure air to the intake pipe of the engine.

The invention relates to a pure electric sanitation vehicle and a power system thereof. The power system comprises a first motor, a first gearbox, a second motor, a second gearbox, a power transmission shaft and a working device. The first motor and the second motor are separately connected with the power transmission shaft through the corresponding gearboxes, the first motor and the second motorcan output power separately or together, and the motors can achieve deceleration torque-increase or speed-increase torque-decrease through the corresponding gearboxes separately. The power system cansimultaneously meet the requirements of high-speed driving and high torque of the vehicle, and the working efficiency of the system is improved; furthermore, a motor with relatively large torque and relatively large output speed is not required, and the cost is reduced; and in addition, the single motor is selected for operation or the two motors are selected for operation at the same time according to different working conditions, it is guaranteed that the motors can work in the high-efficiency operation zone regardless of the working conditions, the motor operation efficiency is improved, the 'a big horse drive s little car' phenomenon is avoided, and vehicle energy consumption is reduced.

The invention solves the problem that is that the pole-changing motor can not change power of output and the power-changing motor can not change poles. The machine winding of the invention includes A, B, C three phases winding. Each phase winding is split into two segments, and each segment has two leading out end separately located in the front and tail. Each segment has m coils (m=1, 2, and the like). There are 12 leading out ends in total motor windings, and they get the following three structures through switching by relay: 1) a double star connection motor winding having P electrodes numbers at first power state; 2) a star connection motor winding having P electrode numbers at second power state; 3) a star connection motor winding having Q poles numbers at second power state.

The invention solves the problem that is that the pole-changing motor can not change power of output and the power-changing motor can not change poles. The machine winding of the invention includes A, B, C three phases winding. Each phase winding is split into two segments, and each segment has two leading out end separately located in the front and tail. Each segment has m coils (m=1, 2, and the like). There are 12 leading out ends in total motor windings, and they get the following three structures through switching by relay: 1) a double star connection motor winding having P electrodes numbers at first power state; 2) a star connection motor winding having P electrode numbers at second power state; 3) a star connection motor winding having Q poles numbers at second power state.

A low voltage, high power and multi-branch three-phase asynchronous motor belongs to the motor technical field; the motor includes a base, a stator winding, a rotor, a junction box and a fan housing;the stator winding is composed of a plurality of star three-phase windings, which can generate revolving magnetic field, work independently, drive the rotor to revolve, and are distributed on the stator symmetrically; the three-phase leading-out wire of each winding is connected with the terminal in the junction box arranged on the asynchronous motor body, electrically connected with an output terminal, a contactor, a frequency converter and a three-phase power supply in order in the junction box which is connected with the winding, to form a power supply parallel circuit which can be controlled solely. The advantages of the motor are as follows: the problem that the low-voltage high-power frequency converter in the frequency conversion speed regulating system is cooled difficultly is solved; when the load of the motor is reduced, the working parallel branch can be changed alternately, which prolongs the useful life of the motor and the contactor; the motor has the advantages of improving work efficiency of the system, saving energy, etc.

The invention discloses a valve hydraulic driver for controlling opening and closing of valve. The hydraulic driver comprises a driver shell, a piston rod and a hydraulic cylinder, wherein the piston rod is slidingly supported on the driver shell via the hydraulic cylinder; the a valve stem shifting yoke is rotatably supported on the driver shell, and a valve stem mounting hole and a shifting pinslot are arranged on the valve stem shifting yoke; and a valve stem shifting pin is fixedly arranged on the piston rod and slidingly positioned in the shifting pin slot on the valve stem shifting yoke. The valve stem shifting yoke is slidingly supported on the driver shell via an upper sliding sleeve and a lower sliding sleeve. The driver not only has large driving force and fast response speed, but also its output torque can be adapted with the variation rule of resisting torque for opening and closing valve. The invention has the advantages of reasonable structure and low cost; and can be widely used for controlling industrial pipeline valve in petroleum industry, chemical industry, ocean engineering and shipping industry.

The invention discloses a multi-inverter speed adjusting system of a low-voltage high-power multi-branch alternating current (AC) motor and pertains to the technical field of electrical engineering and relates to the electric transmission and the motor control of large machinery equipment. The system comprises a low-voltage high-power AC motor and at least two frequency converters, wherein, the low-voltage high-power multi-branch AC motor combines output ends of windings of a plurality of branches in parallel connection to form at least two three-phase output terminal groups each of which is connected with the frequency converters. Each three-phase output terminal group of the low-voltage high-power AC motor and the general low-voltage frequency converter connected with the motor form a separate circuit, thus avoiding the disadvantages of a driving system in which a high-voltage frequency converter supplies power to a high-voltage asynchronous motor. In addition, the general low-voltage frequency converter can adopt an SPWM control method with good output voltage waveforms and meanwhile, the price of the frequency converter is reduced and the reliability of the operation of the frequency converter is guaranteed.

The invention discloses a method for controlling variable speed operation curves by a low head mitergate hydraulic hoist, comprising: (1) connecting a computer with a hydraulic hoist; (2) setting a variable speed opening operation curve and a variable speed closing operation curve of the low head mitergate hoist in a computer; (3) controlling the operation time and the operation speed of the hydraulic hoist by the variable speed opening operation curve and the variable speed closing operation curve of the low head mitergate hoist. Controlling time and speed of the hydraulic hoist is carried out by using the variable speed operation curve of the hoist to satisfy the accurate variable speed opening and closing requirements of a navigation lock service gate, and the low head navigation lock can accurately determine closing and opening force on the premise of doing no model tests to fill the gap in China; the service gate has smooth operation, long service life and lowered maintenance cost under specified closing and opening time so as to avoid the phenomenon of big Marathi car, save power and improve economic benefit and social benefit.

The invention relates to a changeable inertia flywheel energy storage type workover rig, which consists of a power unit, a changeable inertia flywheel set, a gear shifting box, an angle drive box, a roller, a rotary disc, and the like. One end of the changeable inertia flywheel set is connected with the power unit, and the other end of the changeable inertia flywheel set is connected with the gear shifting box; the three groups of flywheels can work simultaneously, or one or two of the flywheels work, thereby realizing the changeable inertia of the flywheels. The energy of a power machine is stored by the changeable inertia flywheels during the subsidiary operation period and is provided for lifting a pipe column, thereby reducing the power of the power machine to one fourth of a conventional workover rig. The changeable inertia flywheels are used to store the gravitational potential energy released by the lowering of the pipe column, thereby realizing the recovery and utilization of the energy. The energy storage in a mode of flywheel kinetic energy improves the efficiency. Three power machine flywheel gear positions are provided for lifting the pipe column, thereby improving thepower utilization rate of the power machine. According to the different weight of the lowered pipe columns, the flywheels with different moments of inertia are used to recover the energy, thereby improving the energy recovery rate.

The invention provides a unit mutual standby ozone generation device which comprises a skid-mounted base, a first unit ozone generator, a second unit ozone generator and a third unit ozone generator are installed on the skid-mounted base, and the first unit ozone generator comprises a first unit ozone power supply and a first unit ozone generation chamber; and the second and third ozone generatorshave the same structure as the first ozone generator. The fund occupation pressure of the ozone standby machine can be reduced, the utilization rate of the standby machine is improved, the field maintenance time is shortened, peak-valley adjustment of sewage treatment loads is facilitated, and the troubleshooting range of fault points is narrowed. Fault positions can be judged quickly on site, and maintenance time is shortened. The starting number of the unit ozone generators can be flexibly adjusted along with the load, the phenomenon of high power for low consumption is avoided, and the standby machine can increase the yield at any time to cope with sudden load increase. The equipment is small in total occupied area and suitable for original site upgrading and capacity expansion transformation of an original pollutant treatment plant, and the civil engineering and occupied cost is reduced.

The invention discloses a hydraulic soft starting motor. A motor stator, a motor rotor, a front auxiliary chamber shell, a pump wheel, a worm gear, a rear auxiliary chamber shell and an output shaft are arranged in the motor shell. The motor rotor, a connection plate, the front auxiliary chamber shell, a connection board and the pump wheel are sequentially connected for transmission. The pump wheel is further connected and fixed with the rear auxiliary chamber shell, and the worm gear is connected and fixed with the output shaft. A soft starting working cavity is composed of the pump wheel and the worm gear, a rear auxiliary chamber is composed of the worm gear and the rear auxiliary chamber shell, and a front auxiliary chamber is composed of the front auxiliary chamber shell and the pump wheel. The front auxiliary chamber is communicated with the working cavity through a guiding pipe, and a throttling valve is installed at the upper end of the guiding pipe. The rear auxiliary chamber is communicated with the working cavity, and the working cavity, the front auxiliary chamber and the rear auxiliary chamber are filled with working liquid. The hydraulic soft starting motor is stable and light in starting, short in starting time, low in current and capable of saving energy and reducing consumption, and impact on an electric grid is small. In addition, the hydraulic soft starting motor has the functions of load balance and overload protection.

The invention belongs to electric motor, especially relates to triphase capacitance double rotor cage electric motor with high starting torque and low running power, which is made up of a stator, a rotor and a shaft. The stator slot of the electric motor is embedded with tow sets of low harmony concentric triphase symmetric phase change double-layer windings, the compensation windings 3-1 is connected with a capacitance C in series, the electric motor double rotor cage arranges two types, one is casting aluminum alloy double rotor cage rotor, the second one is casting aluminum double rotor cage rotor, the double rotor cage rotor is low drain reactance, the work winding and the compensation winding of the stator are connected in parallel onto the triphase power, when starting, the motor outputs high starting torque and inputs low starting current, high starting factor; when the electric motor runs normally, it can output the low power, high efficiency, high power factor, high overloading ability, which is a small 'horse' but driving large car, it saves the energy, belongs to the high efficiency energy-saving electric motor.

The invention discloses a valve hydraulic driver for controlling opening and closing of valve. The hydraulic driver comprises a driver shell, a piston rod and a hydraulic cylinder, wherein the piston rod is slidingly supported on the driver shell via the hydraulic cylinder; the a valve stem shifting yoke is rotatably supported on the driver shell, and a valve stem mounting hole and a shifting pin slot are arranged on the valve stem shifting yoke; and a valve stem shifting pin is fixedly arranged on the piston rod and slidingly positioned in the shifting pin slot on the valve stem shifting yoke. The valve stem shifting yoke is slidingly supported on the driver shell via an upper sliding sleeve and a lower sliding sleeve. The driver not only has large driving force and fast response speed, but also its output torque can be adapted with the variation rule of resisting torque for opening and closing valve. The invention has the advantages of reasonable structure and low cost; and can be widely used for controlling industrial pipeline valve in petroleum industry, chemical industry, ocean engineering and shipping industry.

The invention discloses an air-conditioner refrigerating device and heat recovery method, which comprises the following parts: preheating plate heat-exchanger 1, volume heat-accumulating radiators 2, 3, water-hydrothermal pump 4, channel 9, channel pump 10, wherein the volume heat-accumulating supplement radiator 37 is composed by pipe connection within several controlling valves in the relating position. The heat recovery method comprises the following steps: sending the water at 37 deg.c in the refrigerating tower into the preheating plate heat-exchanger 1; preheating the tap water in the tap water radiator at 35 deg.c then injecting the heat-accumulating radiators 2 or 3; sending the water in heat-accumulating radiators 2 or 3 into heat pump condenser6 to heat at 50 deg.c approximately, which generates the domestic heat water and realizes the circulating heating. The heat-accumulating radiator 37 accumulates the heat at night. The device can adjust the operation condition of present central air-conditioner system cooling water group, which saves the energy.

The invention provides a dispersed-speed flexible motor comprising a motor main body, a stepless speed transmission and a speed reducer, wherein the front end of the motor main body is fixedly provided with a mounting seat, the front end of the motor main body is rotationally provided with a motor rotor output shaft, the stepless speed transmission is arranged in the mounting seat, and the outer side of the mounting seat is fixedly connected with the speed reducer. One end of the stepless speed transmission is connected with a motor rotor output shaft, the other end of the stepless speed transmission is provided with an intermediate transmission shaft, and the stepless speed transmission is rotationally connected with the speed reducer through the intermediate transmission shaft. The dispersed-speed flexible motor has the whole-process flexible transmission performance, the dispersed-speed flexible motor can adaptively isolate the load in the starting process, light-load starting is achieved during starting, an additional starting control device does not need to be added, and the transmission mode can be adaptively adjusted according to the change of the load in the running process. The dispersed-speed flexible motor can be widely applied to type selection of motors in various transmission fields, and can provide various dispersed speed outputs.

The invention discloses a method for controlling a direct current frequency conversion air-conditioner while operating in a refrigeration mode. The method is used for controlling the direct current frequency conversion air-conditioner when the lowest capacity output of the outdoor unit is higher than the capacity requirement of the inner unit, and comprises the following steps: step 1, setting different target low pressure values for various sections of the outdoor ambient temperature; step 2, reducing the operation frequency of a direct current frequency conversion compressor to the lowest operation frequency during the operation process of the direct current frequency conversion air-conditioner according to the requirements on the capability of the indoor unit; and step 3, controlling a first throttle electronic expansion valve, a second throttle electronic expansion valve and an unloading electromagnetic valve to execute corresponding actions according to the low pressure values when the direct current frequency conversion compressor operates in the lowest operation frequency, or controlling the direct current frequency conversion air-conditioner to be started or stopped. With the adoption of the method, the excess capacity output of the outdoor unit is counterbalanced, so that capacity output of the outdoor unit is matched with the lowest capacity requirement of the indoor unit, the normal and stable operation of the direct current frequency conversion air-conditioner is maintained, and the phenomenon that a small trolley is drawn by a horse having large power is prevented.

The invention provides a transformer control system and method and belongs to the technical field of transformer control. The transformer control system of the present invention comprises a first control switch, a parallel transformer group, a second control switch, a data acquisition module and a control processing module. A data acquisition module acquires the voltage and / or current signals of auser-side circuit and sends the signals to the control processing module. The control processing module generates a switch control signal according to the voltage and / or current signals of the user side and the performance parameter of the parallel transformer group to control the synchronous operation of the first control switch and the second control switch to control the working state of the parallel transformer group. The transformer control system of the invention is economical and practical, and has good safety, reliability and stability.