CN107345978B

CN107345978B - Movable control power supply for power plant or intelligent substation and control method

Info

Publication number: CN107345978B
Application number: CN201710486891.XA
Authority: CN
Inventors: 戴宪滨; 戴菁; 戴鹏
Original assignee: Shenyang Institute of Engineering
Current assignee: Shenyang Institute of Engineering
Priority date: 2017-06-23
Filing date: 2017-06-23
Publication date: 2023-07-04
Anticipated expiration: 2037-06-23
Also published as: CN107345978A

Abstract

The invention provides a movable control power supply and a control method for a power plant or an intelligent substation, and relates to the technical field of control of power systems. The control power supply comprises an alternating current input binding post, an alternating current switch, a monitoring module, a power supply module, an insulation monitoring device, an alarm, a direct current switch, a direct current voltmeter, a direct current ammeter, a current sensor, a voltage sensor and a direct current output binding post, wherein the monitoring module receives an upper computer instruction, and adopts a combined digital control mode of fuzzy self-tuning PI control and repeated control to automatically adjust input voltage so as to control the power supply module to output stable direct current voltage, and the insulation monitoring device automatically detects whether a direct current output loop is grounded or insulated well. The invention adopts an integrated and modularized structure, has the functions of digital intelligent monitoring, various protection functions and insulation monitoring and alarming, ensures that the on-site input power supply is convenient to connect, effectively improves the dynamic performance of the control power supply, and ensures that the applied power system runs safely and stably.

Description

Movable control power supply for power plant or intelligent substation and control method

Technical Field

The invention relates to the technical field of control of power systems, in particular to a movable control power supply for a power plant or an intelligent substation and a control method.

Background

In order to ensure safe and stable operation of newly-built or expanded power plants and intelligent substations, the integrity of electric secondary circuits and equipment (relay protection devices, safety automatic devices, control circuits, signal circuits and automatic regulation circuits) must be checked at production sites before the power systems are put into operation. The above-mentioned electric secondary circuit and equipment all need control power supply to drive, and the existing control power supply generally has two types. Firstly, direct current power supplies of a power plant and a transformer substation are used as control power supplies, the indoor fixed installation and metal frame cabinet type structure is adopted, the main device is a storage battery pack, the volume of the storage battery pack is 2360 multiplied by 800 multiplied by 550, and the weight of the storage battery pack is more than 500 kg; before each test, the cable was routed to the field. The second kind, the specialized control power, the main device is made up of three major independent parts of direct-flow power supply appearance, operation control appearance and oscilloscope, it is split type structure; three devices were interconnected in the field prior to each test for integrity testing.

There are a number of problems with existing control test power supplies.

The first control power source has the following problems: (1) the storage battery pack consists of a plurality of storage batteries connected in series and in parallel and is always in a floating charge running state, and because each storage battery has uneven charge and discharge voltage and current, a storage battery polar plate is broken down and damaged, so that the storage battery pack is unreliable and has large running and overhauling workload; (2) each storage battery has serious heat generation, the shell is of a sealing structure, and the body is free of heat dissipation equipment, so that if heat cannot be dissipated in time, the risk of explosion exists; in addition, the plastic shell of each storage battery generates peculiar smell due to heating, and causes pollution to the environment; (3) when secondary equipment such as relay protection and automatic equipment, operating mechanisms of switches, main transformer tap adjusting equipment and the like in the field are tested, test power sources are led from direct current systems of power plants and substations, so that the test power sources are inconvenient, and the quality of the power source voltage is unqualified because of longer lead-in cables and large voltage drop; (4) if the test loop is in direct-current grounding short circuit, the voltage of a direct-current system bus of a power plant and a transformer substation is reduced, so that a 'monitoring, protecting and automatic device' loses a working power supply, and the power system operates under the condition of no monitoring and no protection, and the safe operation of the power system can be endangered; (5) when secondary circuit equipment is tested, if alternating current quantity is connected into a direct current test circuit by mistake, the alternating current quantity can enter a direct current system of a power plant and a transformer substation through the test circuit, and misoperation of relay protection devices at other intervals is caused, so that large-area power failure is caused, and when serious, a power grid is disconnected, and safe and stable operation of a power system is influenced.

The second control power source has the following problems: (1) the traditional transistor amplification type direct current power supply is selected as a control power supply, the output voltage is manually adjusted, the output characteristics are poor, the direct current ripple is large, the output voltage is greatly influenced by a load, and the overcurrent capacity is weak; the power supply has poor man-machine interface, simple protection function and no insulation monitoring and remote communication functions; the power supply has low working efficiency and large weight, and is not suitable for field work; (2) the control power supply adopts a soft switching technology, but the soft switching technology has a plurality of defects, such as: the multiple rectifying modules are operated in parallel, and a feedback loop is increased, so that the stability of the direct current system is affected; (3) poor load carrying capacity with impact; when the high-voltage circuit breakers and relay protection devices of power plants and intelligent substations are in transmission test, the switching-on and switching-off speeds (millisecond level) of the high-voltage circuit breakers are impact loads, so that the output voltage fluctuation of a power supply is large, and the accuracy of the transmission test of the high-voltage circuit breakers and the relay protection devices is affected; (4) the control power supply has a narrow regulation range of outputting direct-current voltage and cannot meet the requirement of direct-current voltage (85-110) U _N When the voltage is changed, the test voltage requirement of the secondary circuit equipment of the power system is met; (5) the control power supply generally has no direct current insulation monitoring function; even if the function is provided, when the direct current two poles (positive pole and negative pole) of the test loop are grounded at the same time, namely symmetry insulation is reduced, the insulation monitoring circuit is insensitive in reaction or refuses to alarm; (6) the power supply controller has slow dynamic response even if adopting a repeated control-digital control mode; although the repeated control can ensure that the power output waveform accurately tracks the given value, the control instruction obtained by the repeated control is not output immediately, but is output after one reference period; if the control power supply is internally interfered, at least one reference period is needed for eliminating the influence of the interference on the output, and the power supply controller does not generate any regulation effect on the interference in one period of the interference occurrence, so that the dynamic performance of the control power supply is seriously influenced.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a movable control power supply and a control method for a power plant or an intelligent substation, which are used for the power plant and the intelligent substation and are used as control power supplies for checking the integrity test of secondary loop equipment, so that the on-site leading-in and input power supply is convenient, the adjustment of the output voltage of the power supply is realized in a manual mode and an automatic mode, the adjustment range is wide, and the test requirement is met; the hardware circuit of the power supply device adopts an integrated and modularized topological structure, has small volume and light weight, has a digital intelligent monitoring function, various protection functions and insulation monitoring and alarming functions, and can effectively improve the dynamic performance of a control power supply so that an applied power system can safely and stably run.

In one aspect, the invention provides a movable control power supply for a power plant or an intelligent substation, which comprises an alternating current input binding post, an alternating current switch, a monitoring module, a power module, an insulation monitoring device, an alarm, a direct current switch, a direct current voltmeter, a direct current ammeter, a current sensor, a voltage sensor and a direct current output binding post;

the first end of the alternating current switch is connected with an alternating current input binding post and is used for being connected with a 220V alternating current input power supply; the power module adopts ER22005/S model, the input end of the power module and the input voltage acquisition end of the monitoring module are both connected to the second end of the alternating current switch, the control receiving end of the power module is connected with the driving control end of the monitoring module through two switch tube control wires, and the power module is used for outputting stable direct current voltage under the control of the monitoring module; the input end of the voltage sensor is connected in parallel with the output end of the power supply module, and the output end of the voltage sensor is connected with the output voltage acquisition end of the monitoring module; the current sensor and the direct current ammeter are sequentially connected in series on a guide wire between the output end of the power supply module and the direct current switch, the output end of the current sensor TA is connected with the output current acquisition end of the monitoring module, and the other end of the direct current switch is connected with the direct current output binding post; the input end of the insulation monitoring device and the direct current voltmeter are both connected in parallel with the output end of the power supply module, the alarm is connected between one output end of the insulation monitoring device and the 220V alternating current working power supply, and the other output end of the insulation monitoring device is directly connected with the 220V alternating current working power supply; the alarm is used for sending out alarm light and sound signals when the direct current output loop of the control power supply is poorly grounded or the insulation is reduced; the voltage sensor and the current sensor are Hall sensors;

The monitoring module is used for receiving instructions of an upper computer of a power plant or an intelligent substation, automatically adjusting the input voltage according to the instructions of the upper computer, monitoring the state of a direct current loop in real time, sending out instructions when faults occur, and rapidly locking the power supply module to output the direct current loop so that the direct current output voltage of a control power supply is zero, and protecting control power supply equipment; the monitoring module comprises a display unit, a control unit and peripheral circuits thereof; the display unit is a liquid crystal display, and the input end of the display unit is connected with the control unit and is used for displaying the values of the alternating current input voltage, the direct current output voltage and the direct current output current acquired by the monitoring module in real time; the control unit is a microprocessor and is used for reading and controlling the voltage and current values of the power output loop, comparing the sampled value with a given voltage base value, and driving a high-frequency converter in the power module to enable the power output end to obtain stable direct-current voltage; the peripheral circuit of the control unit comprises an auxiliary power supply, an input voltage sampling circuit, an output current sampling circuit, a switching tube driving circuit and an RS232 interface circuit;

the auxiliary power supply adopts a silicon rectifying power supply device, and the output end of the auxiliary power supply device is connected with other components of the monitoring module, a current sensor and a voltage sensor and is used for providing direct current working power supply for the components;

The input voltage sampling circuit, the output voltage sampling circuit and the output current sampling circuit are respectively used for converting analog quantities of alternating current input voltage, direct current output voltage and direct current output current into digital quantities for processing by the microprocessor; the input voltage sampling circuit and the output voltage sampling circuit have the same circuit structure, the input ends of the input voltage sampling circuit and the output voltage sampling circuit are respectively used as an input voltage acquisition end and an output voltage acquisition end of the monitoring module, and the output ends of the input voltage sampling circuit and the output voltage acquisition end are connected with the microprocessor; the input end of the output current sampling circuit is used as an output current acquisition end of the monitoring module, is connected with the output end of the current sensor, and the output end of the output current sampling circuit is connected with the microprocessor;

the output end of the switching tube driving circuit is used as a driving control end of the monitoring module and is connected with a control receiving end in the power module, and the input end of the switching tube driving circuit is connected with a PWM square wave output end of the microprocessor and is used for driving a switching tube in the power module to work and protecting the switching tube from overcurrent and overvoltage;

the RS232 interface circuit is connected between the microprocessor and an upper computer of the power plant or the intelligent substation and is used for realizing communication between a control power supply and the upper computer;

The insulation monitoring device is used for automatically detecting the voltage of the positive electrode and the negative electrode of the direct current output loop to the ground and judging whether the direct current loop is grounded or insulated well; the insulation monitoring device comprises two direct

current input terminals

1 and 2, two change-over switches SB, resistors R1, R2, R3, R4, R5 and R6, a voltmeter V, a rectifier bridge U, an optocoupler isolation device IC1, an operational amplifier IC2, a micro relay ZJ and a triode VT; the direct

current input terminals

1 and 2 are respectively connected with the output terminals VOUT+ and VOUT-of the power supply module; one end of each of the two change-over switches SB is respectively connected with the direct

current input terminals

1 and 2, and the other end of each of the two change-over switches SB is connected with the voltmeter V and then grounded; the resistors R1 and R2 are connected in series and then connected in parallel between the direct

current input terminals

1 and 2; the two direct current ends of the rectifier bridge U are respectively connected with the middle nodes of the resistors R1 and R2 and the ground, the two alternating current ends are connected with the two input ends of the optocoupler isolation device IC1, and the two output ends of the optocoupler isolation device IC1 are respectively connected with the direct current power supply VCC and the non-inverting input end of the operational amplifier IC 2; the non-inverting input end of the operational amplifier IC2 is simultaneously connected with the resistor R4 and then grounded, the inverting input end of the operational amplifier IC2 is connected with the resistor R3 and then connected with the direct current power supply VCC, and the inverting input end of the operational amplifier IC2 is simultaneously connected with the resistor R5 and then grounded; the output end of the operational amplifier IC2 is connected with one end of a resistor R6, the other end of the resistor R6 is connected with the base electrode of a triode VT, the collector electrode of the triode VT is connected with a coil of a micro relay ZJ and then is connected with a direct current power supply VCC, and a movable contact terminal 3 and a movable contact terminal 4 of the micro relay ZJ are used as the output end of the insulation monitoring device.

Preferably, the mobile control power supply for a power plant or an intelligent substation further comprises a surge suppressor; the surge suppressor is used for preventing the AC220V alternating current input end of the control power supply from generating surge overvoltage due to lightning strike, the surge suppressor is connected to the second end of the alternating current switch through the auxiliary alternating current switch, and the grounding end of the surge suppressor is grounded.

Preferably, the movable control power supply for the power plant or the intelligent substation further comprises a power supply case, wherein the power supply case is used for bearing and installing other components of the control power supply, and comprises a case body, a front end cover, a case lock, a mounting panel, a rear end cover plate and a handle; the box body shell is grounded, and the box is locked at the joint of the front end cover and the box body; the installation panel is arranged on the rear side of the front end cover, an alternating current input binding post, an alternating current switch, a monitoring module, a power module, an insulation monitoring device, an alarm, a direct current switch, a direct current voltmeter, a direct current ammeter, a surge suppressor, a direct current output binding post and a grounding terminal are embedded and installed on the installation panel, and the grounding terminal is used for connecting the grounding end of the surge suppressor; the rear end cover plate and the box body are of an integrated structure, and 2 fans are fixedly arranged on the rear end cover plate in an embedded mode; the handle is arranged on one side surface of the box body.

Preferably, the peripheral circuit of the monitoring module further comprises a fan driving circuit, the output end of the fan driving circuit is used as a temperature control end and is connected with 2 fans on the power supply case, and the input end of the fan driving circuit is connected with the PWM square wave output end of the microprocessor and used for driving and controlling the fans to perform heat dissipation and temperature adjustment on the power devices in the control power supply.

Preferably, the power module is mounted on the mounting panel through a power module bracket, the power module bracket comprises two supports, a supporting panel and a limiting structure, the two supports are two symmetrical U-shaped bases with openings oppositely placed, and 2 bracket base bolts are respectively arranged at the lower ends of the two U-shaped bases and are used for being fixed with the mounting panel of the power chassis; the support panel is fixed to be located the upper end of two U type bases, limit structure is two parallels and fixed locating angle bar on the support panel for control fixed power supply module.

Preferably, the materials of the box body and the mounting panel are aluminum plates with the thickness of 2.0mm, and the box body is subjected to spray coating treatment; the front end cover is lined with hemispherical black sponge and is lined with a sealing piece; the box lock is provided with four handles which are respectively symmetrically arranged at two sides of the butt joint part of the front end cover and the box body.

On the other hand, the invention also provides a method for controlling the power supply of the power plant or the intelligent substation by adopting the movable control power supply for the power plant or the intelligent substation, which comprises two modes of automatic control and manual adjustment;

In a manual regulation mode, a worker judges whether the output voltage needs to be regulated according to the comparison between the direct current voltage representation number of the output end of the power supply module and a preset reference output voltage, when the difference value between the actual output voltage and the reference output voltage exceeds a preset error, the output voltage needs to be regulated, and the direct current output voltage of the power supply is controlled to be reduced by 1V by pressing a +. +.2 'key every time on a power supply module panel and is increased by 1V by pressing a +. +.2' key every time;

in the automatic control mode, an upper computer of a power plant or an intelligent substation sends an instruction to a monitoring module through an RS232 interface circuit, the monitoring module adopts a composite digital control mode of combining fuzzy self-setting PI control and repeated control, namely, the steady-state characteristic of the output of a control power supply is improved by adopting repeated control, and the dynamic characteristic of the output of the control power supply is improved by adopting fuzzy self-setting PI control, and the specific method is as follows:

step 1: setting a reference output voltage Uset and a preset error e;

step 2: the voltage sensor monitors the output voltage Ut of the output end of the power supply module in real time, and calculates an error value e (K) of the output voltage Ut and a reference output voltage Uset in the monitoring module, wherein K represents a kth sampling point, and k=1, 2, …, K and k=sampling speed/50;

Step 3: judging whether the error value e (k) is larger than a preset error e or not; if yes, controlling the power supply to be in a dynamic change state, and executing the step 4; if not, controlling the power supply to be in a steady state operation state, and executing the step 5;

step 4: entering a fuzzy self-tuning PI control mode, fuzzifying an error value e (k) and a difference value ec (k) between the error value e (k) and an error value e (k-1) calculated in the last control adjustment, performing fuzzy reasoning by looking up a table, determining a proportional coefficient delta Kp and an integral coefficient delta Ki, performing fuzzy calculation, immediately performing PI adjustment on the output voltage of a control power supply, and returning to the step 2; where ec (k) =e (k) -e (k-1), when k=1, ec (k) =e (k);

step 5: and (3) in a repeated control mode, repeatedly executing the step (2) and the step (3) in a reference period N to obtain an error value e (k) of each sampling point, and after the delay of one reference period is finished, carrying out corresponding phase and amplitude compensation adjustment on the output voltage Ut of the control power supply by the repeated controller to update the output voltage, wherein the compensated output voltage is Uo (k) =0.95 Uo (k-N) +e (k), uo (k) represents the compensated output voltage, uo (k-N) represents the output voltage after k-N times of compensation, and N represents the period sampling beat number.

Preferably, the preset error e is set as the rated voltage U of the output end of the power supply module _N 5% of (C).

According to the technical scheme, the beneficial effects of the invention are as follows: the movable control power supply and the control method for the power plant or the intelligent substation are used for the power plant and the intelligent substation and are used as control power supplies for checking and monitoring equipment, control equipment, relay protection and automatic equipment, operating mechanisms of switches, tap adjusting equipment of a main transformer and other secondary loop equipment integrity tests, so that the on-site leading-in and input power supply is convenient, the power supply output voltage adjustment has two modes of manual and automatic, the adjustment range is wide, and the (30-150)% U can be realized _N Adjusting the range to meet the test requirement; the hardware circuit of the power supply device adopts an integrated and modularized topological structure, has small volume and light weight, is convenient to move and carry, has a digital intelligent monitoring function, various protection functions and insulation monitoring and alarming functions, and can effectively improve the dynamic performance of a control power supply so that an applied power system can safely and stably run. The specific functions are as follows:

(1) Intelligent monitoring function: (1) the automatic locking function is that when the monitoring module detects that the on-site direct current test loop fails, an instruction is sent out, the output loop of the power supply module is quickly locked, so that the direct current output voltage of the control power supply is zero, and the control power supply equipment is protected; (2) the automatic control function of the cooling fan is realized, the monitoring module comprehensively detects the direct current output current of the control power supply, and the automatic start-stop control of the fan is realized, so that the aim of good heat dissipation is achieved; (3) the communication function is to upload the direct current output voltage and current value, protection and alarm information of the control power supply to the upper computer of the power plant and transformer substation monitoring system by using the communication interface of the monitoring module, and to receive the instruction downloaded by the upper computer to control the control power supply;

(2) The protection function: (1) the overvoltage, low voltage and disconnection protection of the voltage loop of the alternating current input loop, the automatic locking control of the output voltage and current of the power supply, the shutdown alarm and the automatic recovery after the voltage is normal; (2) the overvoltage, low voltage and short-circuit protection of the output loop control the output current limit of the power supply, and the power supply is automatically recovered after the fault is removed; (3) the overheat protection is realized, the monitoring module comprehensively detects the direct current output current of the control power supply, realizes the automatic start-stop control of the fan, achieves the aim of good heat dissipation, and automatically recovers after the temperature is normal when the overheat protection detects that the temperature of the control power supply is too high; (4) the lightning protection is realized, 1 surge suppressor is arranged at the AC220KV alternating current input end of the control power supply, and overvoltage caused by lightning surge can be effectively avoided.

(3) Direct current loop insulation monitoring and alarm function: when the on-site direct current test loop is grounded or insulated is lowered, the insulation monitoring device acts, the movable contact is closed, the alarm is started, the alarm emits light and audible alarm signals, and the insulation integrity of the direct current output loop of the automatic monitoring control power supply is realized.

Drawings

Fig. 1 is a schematic diagram of a power supply chassis according to an embodiment of the present invention;

FIG. 2 is a schematic view of a rear end cap plate according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a layout of devices on a mounting panel according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of a power module bracket according to an embodiment of the present invention;

FIG. 5 is a control power supply wiring diagram provided by an embodiment of the present invention;

FIG. 6 is a circuit connection block diagram of a monitoring module according to an embodiment of the present invention;

FIG. 7 is a schematic diagram of a voltage sampling circuit according to an embodiment of the present invention;

FIG. 8 is a schematic diagram of a current sampling circuit according to an embodiment of the present invention;

FIG. 9 is a schematic diagram of a driving circuit of a switching tube according to an embodiment of the present invention;

FIG. 10 is a schematic diagram of a fan driving circuit according to an embodiment of the present invention;

FIG. 11 is a schematic diagram of an RS232 level shift circuit according to an embodiment of the present invention;

FIG. 12 is a schematic circuit diagram of an insulation monitoring device according to an embodiment of the present invention;

fig. 13 is an automatic composite digital control flow chart of a power control method according to an embodiment of the present invention.

In the figure: 101. a case; 102. a front end cover; 103. a box lock; 104. installing a panel; 105. a rear end cap plate; 106. a handle; 107. a fan; 108: a fixing bolt; 109. a U-shaped base; 1010. a support panel; 1011. a bracket base bolt; 1012. angle iron.

Detailed Description

The following describes in further detail the embodiments of the present invention with reference to the drawings and examples. The following examples are illustrative of the invention and are not intended to limit the scope of the invention.

A movable control power supply for a power plant or an intelligent substation comprises a power supply case, and an alternating current input binding post, an alternating current switch, a monitoring module, a power supply module, an insulation monitoring device, an alarm, a direct current switch, a direct current voltmeter, a direct current ammeter, a current sensor, a voltage sensor, a surge suppressor, a grounding terminal and a direct current output binding post which are arranged in the power supply case.

The power supply cabinet is used for bearing and installing other components for controlling a power supply, and comprises a cabinet body 101, a front end cover 102, a cabinet lock 103, a mounting panel 104, a rear end cover plate 105 and a handle 106 as shown in fig. 1. The material of the box body 101 is an aluminum plate with the thickness of 2.0mm, the hinge is connected by stainless steel hardware through spraying treatment, so that the fixing strength of the box body is improved, the shell is high in compression resistance and strength and light in weight, the electrostatic shielding effect on electrical elements in a machine box is good, the shell of the box body 101 is reliably grounded, and the safety of field test personnel is ensured. The chassis front end cover 102 is lined with hemispherical black sponge (ethylene-vinyl acetate copolymer is a novel environment-friendly rubber plastic material) and is lined with a sealing piece, and has the characteristics of good shock resistance, heat insulation, moisture resistance, corrosion resistance, dust prevention effect and the like. The box lock 103 is arranged at the butt joint of the front end cover 102 and the box body 101, in this embodiment, four locks are installed on the front end cover 102, and the four locks are symmetrically arranged at two sides of the butt joint of the front end cover 102 and the box body 101 respectively, so that the front end cover and the box body are convenient to assemble and disassemble in field test. The mounting panel 104 is arranged on the rear side of the front end cover 102, is a 2.0mm thick aluminum plate, is mounted on a circle of metal angle arranged on the inner wall of the power supply case, and is fixed with the metal angle by using 4 fixing bolts 108. The rear end cover plate 105 and the box body 101 are of an integrated structure and are made of aluminum plates with the thickness of 2.0mm, 2 fans 107 are fixedly installed on the rear end cover plate 105 in an embedded mode, each fan is fixed on the rear end cover plate 105 through 4 fixing bolts 108, and the specification model of each fan is XHA25489B2 as shown in fig. 2. The handle 106 is arranged on one side surface of the box body 101, and is convenient to move and carry.

The mounting panel 104 is embedded with ac input terminals L and N, ac switches QF and QF2, a monitor module, a power module, an insulation monitor, an alarm FM, a dc switch QF1, a dc voltmeter PV, a dc ammeter PA, a current sensor TA, a voltage sensor TV, a surge suppressor F1, dc output terminals "+", "-" and a ground terminal, and the layout of these devices is shown in fig. 3. The alternating current input binding posts L and N are respectively green and black, and the model is JXZ-1/1;2 AC switches QF and QF2, the model is S262-C16/2P-AC; the surge suppressor F1 is of the model SPNSA100/2P; the power supply module is ER22005/S;1 red alarm FM, model LY33-22; the direct current voltmeter and the ammeter are 1 block each, and the models are ZF5135-V and ZF5135-A respectively; the voltage sensor TV and the current sensor TA are Hall sensors, and the model numbers are HNV025A, HNC025A respectively; the direct current output binding posts "+" and "-" are respectively red and black, and the model is JXZ-1/1; the direct current switch QF1 is of the model S262-C10/2P-DC; the grounding terminal is yellow and has the model number of JXZ-1/1.

The power module is mounted on the mounting panel 104 through a power module bracket, the power module bracket is shown in fig. 4, and the bracket is made of a 2.0mm thick aluminum plate and comprises two supports, a supporting panel 1010 and a limiting structure, wherein the two supports are two symmetrical U-shaped bases 109 with opposite openings, and 2 bracket base screws 1011 are respectively arranged at the lower ends of the two U-shaped bases 109 and are used for being fixed with the mounting panel 104 of the power chassis; the support panel 1010 is fixedly arranged at the upper ends of the two U-shaped bases 109; the limit structure is two parallel angle irons 1012 fixedly arranged on the support panel and is made of a 1.0mm thick aluminum plate and used for fixing the power supply module left and right.

The wiring diagram of the control power supply is shown in FIG. 5, the first end of the AC switch QF (terminal 1 and terminal 2 of QF) adopts BVR-2.5mm ² The black lead is connected with the alternating current input binding posts L and N and used for connecting a 220V alternating current input power supply, and the input end ACL and ACN of the power supply module and the input voltage acquisition end (the terminal 2 and the terminal 1 of the monitoring module) of the monitoring module respectively adopt BVR-2.5mm ² And BVR-1.0mm ² The black wire is connected to the second end (terminal 3 and terminal 4 of QF) of the ac switch QF, and the power module is used for outputting stable dc voltage under the control of the monitoring module. The surge suppressor F1 is connected to the second end of the alternating current switch QF through the auxiliary alternating current switch QF2, and the ground end and the ground terminal of the surge suppressor F1 adopt BVR-2.5mm ² The yellow-green double-color lead is connected, and BVR-2.5mm is adopted between the AC input binding posts L and N and the

terminals

1 and 2 of the AC switch QF2 respectively ² Black lead connection, BVR-2.5mm is adopted between the terminal 3 and the terminal 4 of the alternating current switch QF2 and the terminal 1 and the terminal 2 of the surge suppressor F1 respectively ² Black wires are connected. The control receiving ends 485A and 485B of the power supply module are connected with the driving control end (the terminal 3 and the terminal 4 of the monitoring module) of the monitoring module through two switching tube control leads L1 and L2, so as to realize the functions of adjusting and protecting the output voltage of the control power supply, and the two switching tube control leads L1 and L2 are BVR-1.0mm ² Black wires. The input end of the voltage sensor TV is connected in parallel with the output ends VOUT+ and VOUT-of the power supply module, the output end of the voltage sensor TV is connected with the output voltage acquisition end (terminal 10 of the monitoring module) of the monitoring module, and BVR-1.0mm is adopted ² Black wires. The current sensor TA and the DC ammeter PA are dependent onThe secondary series connection is arranged on a lead between the output end VOUT+ of the power supply module and the terminal 1 of the direct current switch QF1, the output end of the current sensor TA is connected with the output current acquisition end (the terminal 9 of the monitoring module) of the monitoring module, the terminal VOUT-of the power supply module is directly connected with the terminal 2 of the QF1, the other end (the terminal 3 and the terminal 4 of the QF 1) of the direct current switch QF1 is connected with direct current output terminals "+" and "-", and BVR-2.5mm is adopted ² Black wires. In the field test, the dc output terminals "+" and "-" are connected to the test load (field secondary equipment). The input end of the insulation monitoring device JCJ (terminal 1 and terminal 2 of JCJ) and the direct-current voltmeter PV both adopt BVR-1.0mm ² The black lead is connected in parallel with the output ends VOUT+ and VOUT-of the power supply module. The alarm FM is connected between one output end (terminal 4 of JCJ) of the insulation monitoring device JCJ and 220V alternating current working power supply, and the other output end (terminal 3 of JCJ) of the insulation monitoring device JCJ is directly connected with 220V alternating current working power supply, and BVR-1.0mm is adopted ² The black lead and the alarm FM are used for sending out alarm light and sound signals when the direct current output loop of the control power supply is poorly grounded or insulated to be reduced. The fan M is connected to the temperature control end (terminal 11 and terminal 12 of the monitor module) of the monitor module for radiating heat from the control power supply.

The monitoring module is used for receiving instructions of an upper computer of a power plant or an intelligent substation, automatically adjusting input voltage according to the instructions of the upper computer, monitoring the state of a direct current loop in real time, sending out instructions when faults occur, rapidly locking the power supply module to output the direct current loop, enabling the direct current output voltage of a control power supply to be zero, protecting control power supply equipment, and realizing the functions of measuring output parameters of the control power supply, adjusting voltage, protecting, controlling temperature and communicating. The circuit connection block diagram of the monitoring module is shown in fig. 6, and comprises a display unit, a control unit and peripheral circuits thereof. The display unit is a liquid crystal display and is used for displaying the values of the alternating current input voltage, the direct current output voltage and the direct current output current acquired by the monitoring module in real time. The control unit is a microprocessor and is used for reading and controlling the voltage and current values of the power output loop, comparing the sampled value with a given voltage base value, and driving the high-frequency converter in the power module to enable the power output end to obtain stable direct-current voltage. The peripheral circuits of the control unit comprise an auxiliary power supply, an input voltage sampling circuit, an output current sampling circuit, a switching tube driving circuit, a fan driving circuit and an RS232 interface circuit.

In the embodiment, the model of the microprocessor is TMS320F2812, and the model of the liquid crystal display is HY-12864. The maximum display range of the liquid crystal display screen is 128 x 64, and two HD61202 liquid crystal display control drivers are arranged in the display. Pins IOP3, 4, 5, 6, 7 and IOPB0-IOPB7 of the liquid crystal display HY-12864 are respectively connected with pins RS data or instruction signals, R/W read-write signals, CS1, CS2 left and right screen selection signals, E enable signals and DB0-DB7 data buses of the microprocessor TMS320F 2812.

The output end of the auxiliary power supply is connected with other component devices of the monitoring module, the current sensor and the voltage sensor and is used for providing direct current working power supply for the components. In the embodiment, the auxiliary power supply is a BKZ-5A 220 Zhengtai silicon rectifying power supply device. The power supply is 220V alternating current input (namely a terminal 13 and a terminal 14 of the monitoring module), a power frequency transformer with 20W power is subjected to full-bridge rectification to obtain 30V direct current voltage, three paths of output voltages (+ -15V, 3.3V and 5V) are realized through the isolation DC/DC module, and a direct current working power supply is provided for components (namely a microprocessor, an input voltage sampling circuit, an output current sampling circuit, a switching tube driving circuit, a fan driving circuit and an RS232 interface circuit) of the monitoring module.

The input voltage sampling circuit, the output voltage sampling circuit and the output current sampling circuit are respectively used for converting analog quantities of alternating current input voltage, direct current output voltage and direct current output current into digital quantities for processing by the microprocessor.

The input voltage sampling circuit and the output voltage sampling circuit have the same circuit structure, and the input ends of the input voltage sampling circuit and the output voltage sampling circuit are respectively used as an input voltage acquisition end and an output voltage acquisition end of the monitoring module. As shown in fig. 7, the input voltage sampling circuit or the output voltage sampling circuit is composed of two voltage dividing resistors R30 and R31, an input resistor R32, two operational amplifiers U2A and U5A, a resistor R33, a linear optocoupler U4, a polar capacitor C20, capacitors C32 and C33, a feedback resistor R34, and a light emitting diode D3. One end of the divider resistor R30 is used as an input end of the voltage sampling circuit and is connected with an output end of the HNV025A type Hall sensor TV; the 2 pin and the 4 pin of the linear optocoupler U4 are connected with the positive electrode and the negative electrode of a 15V direct current power supply of the auxiliary power supply; the +3.3V direct current power supply at one end of the light emitting diode D3 is connected with the +3.3V direct current power supply provided by the auxiliary power supply; the output end of the operational amplifier U5A is an output end ADC1 of the voltage sampling circuit and is connected with an ADC terminal of the microprocessor; the power ends of the two operational amplifiers are connected with a 15V direct current power supply provided by an auxiliary power supply. In this embodiment, the linear optocoupler U4 is of the type HCNR 201.

The voltage sampling circuit takes the voltage division of the resistors R30 and R31 as input quantity, the input quantity is adjusted by utilizing the operational amplifier U2A, and the linear optocoupler U4 is used for carrying out photoelectric isolation on strong and weak electric signals in the voltage sampling circuit; the linear optocoupler isolates current, and the operational amplifier U5A is connected at the input and the output to realize voltage isolation.

The input end of the output current sampling circuit is used as the output current acquisition end of the monitoring module and is connected with the output end of the current sensor TA, and the circuit is composed of resistors R21, R22, R23 and R24, a capacitor C21, a polar capacitor C22 and an operational amplifier U11A as shown in FIG. 8. One end of the input resistor R21 is used as an input end of the output current sampling circuit and is connected with an output end of the HNA025A type Hall sensor TA; one end of the resistor R24 is connected with the output end of the operational amplifier, and the other end of the resistor R is connected with an ADC terminal of the microprocessor as an output end ADC2 of the output current sampling circuit. The power ends of the operational amplifiers are connected with a 15V direct current power supply provided by an auxiliary power supply. The current sensor TA realizes the isolation of the high-low voltage circuit; in order to meet the requirement of AD sampling of the microprocessor chip, the current signal output by the sensor is regulated by the operational amplifier U11A, and the current signal is converted into a voltage signal of 0-3.3V.

The output end of the switching tube driving circuit is used as a driving control end of the monitoring module and is connected with a control receiving end in the power module, and the switching tube driving circuit is used for driving the switching tube in the power module to work and protecting the switching tube from overcurrent and overvoltage. As shown in fig. 9, the switching tube driving circuit is composed of a switching tube driving module 4D1 and its peripheral circuits. The switching tube driving module 4D1 is of the model EXB841. The pin DSI-of the switch tube driving module 4D1 is connected with the terminal PWM of the microprocessor through the triode A1; the output terminal 3 and the terminal 4 of the driving circuit are respectively connected with the terminal 485A and the terminal 485B of the power module and are used for driving a switching tube in the power module to work; the DC power supply VDD5V takes +5V voltage output by the auxiliary power supply.

The switching tube driving circuit isolates and amplifies PWM square waves generated by the microprocessor through the switching tube driving module 4D1, converts the PWM square waves into power signals capable of stably driving on and off of a switching tube in the power supply module, and achieves output voltage adjustment of a control power supply and overcurrent and overvoltage protection of the switching tube.

The output end of the fan driving circuit is used as a temperature control end of the monitoring module and is connected with 2 fans on the power supply case, and the fan driving circuit is used for driving and controlling the fans to radiate and regulate the temperature of the power devices in the control power supply. As shown in fig. 10, the fan driving circuit is composed of a photo coupler U1, resistors R55, R2, R3, R4, capacitors C6, C7, C9, and a zener diode Z1. The photo-coupler U1 is of the type TLP250. Pin in+ of the photo coupler U1 is used as an input end of a fan driving circuit, connected with a PWM1 terminal of the microprocessor, and an output terminal 11 and an output terminal 12 are respectively connected with 2 cooling fans; the +15V is taken to the +15V voltage output by the auxiliary power supply.

The fan driving circuit amplifies PWM square waves generated by the microprocessor, converts the PWM square waves into power signals capable of stably driving the fan motor, and achieves start-stop control of the fan motor, so that the temperature of each component module of the control power supply is reduced. The power supply case can adopt a heat dissipation mode combining self-cooling and air cooling. When in light load, self-cooling operation is adopted for heat dissipation; when the load is heavy, the monitoring module automatically detects the direct current output current of the control power supply, and controls the cooling fan on the rear cover plate of the power supply case to start and stop, so that the cooling effect is good.

The RS232 interface circuit is used for implementing communication between the control power supply and the upper computer, and as shown in fig. 11, is composed of a level shifter MAX3221 and its peripheral circuits. The pin 11 and the pin 9 of the level converter MAX3221 are respectively used as communication interface ends of the monitoring module, namely the terminal 5 and the terminal 6 of the monitoring module, and are connected with an upper computer of a power plant or an intelligent substation; pin 13 and pin 8 of level shifter MAX3221 are connected to terminal SCI-A of the microprocessor; pin 15 and pin 16 of the level shifter MAX3221 are connected to the auxiliary power supply output ±3.3v.

The RS232 interface circuit realizes the communication function of controlling the power supply and the upper computer of remote measurement, remote signaling and remote control. Because the SCI-A level of the general serial port of the microprocessor is inconsistent with the standard 232 level signal, the level of the microprocessor needs to be converted when communicating with the upper computer, so that the RS232 interface circuit in the embodiment adopts MAX3221 as a level converter. When communication is uplink, converting the UART chip level of the microprocessor into the standard level of RS 232; when communication goes down, the RS232 level on the bus is converted into the 3.3V level of the microprocessor, so that the communication with the upper computer is realized.

The insulation monitoring device adopts an unbalanced bridge voltage division ratio principle, is used for automatically detecting the voltage of the positive electrode and the negative electrode of the direct current loop to the ground, judging whether the direct current output loop is grounded or insulated well, solving the problem that the insulation monitoring device is out of order or refused to act when the two poles (positive electrode and negative electrode) of the on-site direct current test loop are grounded symmetrically, and improving the sensitivity of the insulation monitoring device. The insulation monitoring device is shown in fig. 12, and comprises two direct

current input terminals

1 and 2, two change-over switches SB, resistors R1, R2, R3, R4, R5, R6, a voltmeter V, a rectifier bridge U, an optocoupler isolation device IC1, an operational amplifier IC2, a micro relay ZJ and a triode VT. The model of the change-over switch SB is LW-10D, the resistance values of the resistors R1, R2, R3, R4, R5 and R6 are 200kΩ, 80kΩ, 2kΩ, 1kΩ, 2kΩ and 1kΩ respectively, the model of the voltmeter V is ZF5135-V, the rectifier bridge U is composed of 4 diodes with the model of DSEI2X6112B, the model of the opto-coupler isolation device IC1 is HCNR201, the model of the operational amplifier IC2 is LM324, +15V is taken TO the output circuit of the auxiliary power supply, the model of the micro relay ZJ is JD2912, the terminal 3 and the terminal 4 of the ZJ are the contact points, and the model of the triode VT is ISC-TO251. The direct current input terminals 1 and 2 are respectively connected with the output terminals VOUT+ and VOUT-of the power supply module; one end of each of the two change-over switches SB is respectively connected with the direct current input terminals 1 and 2, and the other end of each of the two change-over switches SB is connected with the voltmeter V and then grounded; the resistors R1 and R2 are connected in series and then connected in parallel between the direct current input terminals 1 and 2; the positive DC end of the rectifier bridge U is connected with the middle nodes of the resistors R1 and R2, the negative DC end is grounded, the two AC ends are connected with the two input ends of the optocoupler isolation device IC1, and the two output ends of the optocoupler isolation device IC1 are respectively connected with the direct current power supply VCC and the positive input end of the operational amplifier IC 2; the non-inverting input end of the operational amplifier IC2 is simultaneously connected with the resistor R4 and then grounded, the inverting input end of the operational amplifier IC2 is connected with the resistor R3 and then connected with the direct current power supply VCC, and the inverting input end of the operational amplifier IC2 is simultaneously connected with the resistor R5 and then grounded; the output end of the operational amplifier IC2 is connected with one end of a resistor R6, the other end of the resistor R6 is connected with the base electrode of a triode VT, the collector electrode of the triode VT is connected with a direct current power supply VCC after being connected with a coil of a micro relay ZJ, and a movable contact terminal 3 and a terminal 4 of the micro relay ZJ are used as the output end of an insulation monitoring device JCJ, namely a terminal 3 and a terminal 4 of the insulation monitoring device JCJ in FIG. 5.

The unbalanced bridge is an asymmetric circuit formed by R1 and R2 (R1 is equal to R2), a ground insulation resistor R+ of the direct current input end 1 and a ground insulation resistor R-of the direct current input end 2, and the input end of the rectifier bridge U is connected with the asymmetric bridge. When the positive electrode or the negative electrode of the field direct current test loop is grounded or the positive electrode and the negative electrode are grounded simultaneously, the input end of the rectifier bridge U acquires the output voltage of the asymmetric bridge, the rectifier bridge U generates an output signal, the output signal is isolated by the optocoupler isolation device IC1 and then is added into the input end of the operational amplifier IC2, finally the output signal is amplified by the operational amplifier IC2, the voltmeter V is conducted, the ZJ coil of the micro relay is excited to act, the ZJ movable contact is closed, and the field direct current test loop grounding alarm signal is sent.

The method for detecting the insulation resistance of the positive electrode to the ground and the negative electrode to the ground of the direct current test loop on site comprises the following steps:

(1) operating a change-over switch SB to enable SB1-2 and SB3-4 to be closed, obtaining the positive electrode grounding voltage V+1 of the field direct current test loop according to V+ detected by a voltmeter V, and obtaining the negative electrode grounding voltage V-1 by the detected V-;

(2) operating a change-over switch SB to enable SB1-2 to be opened and SB3-4 to be closed, obtaining the positive electrode grounding voltage V+2 of the field direct current test loop according to V+ detected by a voltmeter V, and obtaining the negative electrode grounding voltage V-2 according to the detected V-;

(3) Operating a change-over switch SB to enable SB1-2 to be closed and SB3-4 to be opened, obtaining the positive electrode grounding voltage V+3 of the field direct current test loop according to V+ detected by a voltmeter V, and obtaining the negative electrode grounding voltage V-3 according to the detected V-;

according to the measured data, the positive electrode ground resistance of the DC test loop with the appearance field can be calculated to be R+ = [ V-1 x V+2)/(V-2 x V+1) -1 ] 200 (kΩ); the negative electrode ground resistance of the field direct current test loop is R= [ V-3 x V+1)/(V-1 x V+3) -1 ] x 200 (kΩ).

The method for controlling the power supply of the power plant or the intelligent substation by adopting the movable control power supply for the power plant or the intelligent substation comprises two modes of automatic control and manual adjustment.

In the manual regulation mode, a worker judges whether the output voltage needs to be regulated according to the comparison between the direct current voltage representation number of the output end of the power supply module and a preset reference output voltage, when the difference value between the actual output voltage and the reference output voltage exceeds a preset error, the output voltage needs to be regulated, and the direct current output voltage of the power supply is controlled to be reduced by 1V by pressing a +..

In the automatic control mode, an upper computer of a power plant or an intelligent substation sends an instruction to a monitoring module through an RS232 interface circuit, the monitoring module adopts a composite digital control mode of combining fuzzy self-setting PI control and repeated control, namely, the steady-state characteristic of the output of a control power supply is improved by adopting repeated control, and the dynamic characteristic of the output of the control power supply is improved by adopting fuzzy self-setting PI control, so that the manual mode cannot be interfered at the moment. The specific method of the automatic control method is as follows.

Step 1: setting a reference output voltage Uset and a preset error e, wherein the preset error e is set as a rated voltage U of an output end of the power supply module _N 5% of (2);

after the preset value is set, composite digital control is performed, as shown in fig. 13, and the specific method is as follows:

step 3: judging whether the error value e (k) is larger than a preset error e or not; if yes (for example, the secondary loop load of the field test suddenly changes or the direct current voltage suddenly changes), the power supply is controlled to be in a dynamic change state, and the step 4 is executed; if not, controlling the power supply to be in a steady state operation state, and executing the step 5;

Step 4: the method comprises the steps of entering a fuzzy self-tuning PI control mode, enabling a fuzzy self-tuning PI controller to feel output voltage mutation, calculating deviation between an actual output value y (t) and a given value r (t), determining that DeltaKp is a proportional coefficient, integrating the coefficient by DeltaKi, and performing fuzzy calculation, specifically, fuzzifying an error value e (k) and a difference value ec (k) between the error value e (k) and an error value e (k-1) calculated in the last control adjustment, wherein ec (k) =e (k) -e (k-1), when k=1, performing fuzzy reasoning on ec (k) =e (k), determining the proportional coefficient DeltaKp and the integral coefficient DeltaKi, performing fuzzy calculation, immediately performing PI adjustment on the control power supply output voltage, returning to step 2, and continuously monitoring the real-time output voltage until the output voltage of the control power supply is restored to a new stable state;

step 5: the repeated control mode is entered, the step 2 and the step 3 are repeatedly executed in a reference period N, corresponding phase and amplitude compensation adjustment is carried out on the output voltage Ut according to the calculated error value e (k), and the output voltage is updated; the compensated output voltage is Uo (k) =0.95 Uo (k-N) +e (k), wherein Uo (k) represents the compensated output voltage, uo (k-N) represents the k-N times of the compensated output voltage, N represents the number of periodical sampling beats, and the output quantity is accumulated once every other period (N steps), and the accumulation is that the value of the period on the output quantity is weakened by 5 percent firstly, and then the current value e (k) of the input quantity is added; after a delay of one reference period, the repetitive controller generates a compensation adjustment effect on the output voltage of the control power supply. The delay refers to that the control command of the repeated control is not executed immediately but is executed after one reference period, and the control strategy delays the forward channel generated by the link Cycle delay link Z connected in series ^-N Delaying the control action by one cycle, namely: the error information detected in this period starts to affect the control amount in the next period.

The movable control power supply and the control method for the power plant or the intelligent substation are provided by the embodiment, the alternating-current input power supply is of a single-phase alternating-current 220V voltage level, and the low-voltage alternating-current power supply is conveniently connected on site; the direct-current voltage output by the control power supply has two manual and automatic adjustment modes, and the adjustment range is wide, and can realize (30-150)% U _N And the range is adjusted, so that the test voltage requirement of the field secondary loop equipment is met. The control power hardware circuit adopts an integrated and modularized topological structure, has small volume (210 multiplied by 320 multiplied by 500), light weight (3.5 kg) and is convenient to move and carry. The specific functions are as follows:

(2) The protection function: (1) the overvoltage, low voltage and disconnection protection of the voltage loop of the alternating current input loop, the automatic locking control of the output voltage and current of the power supply, the shutdown alarm and the automatic recovery after the voltage is normal; (2) the overvoltage, low voltage and short-circuit protection of the output loop control the output current limit of the power supply, and the power supply is automatically recovered after the fault is removed; (3) the overheat protection is realized, the monitoring module comprehensively detects the direct current output current of the control power supply, realizes the automatic start-stop control of the fan, achieves the aim of good heat dissipation, and automatically restores after the temperature is normal when shutdown warning is carried out when the temperature of the control power supply is detected to be too high (the temperature is more than or equal to 70+/-5 ℃); (4) the lightning protection is realized, 1 surge suppressor is arranged at the AC220KV alternating current input end of the control power supply, and overvoltage caused by lightning surge can be effectively avoided;

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and are not limiting; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced with equivalents; such modifications and substitutions do not depart from the spirit of the corresponding technical solutions, which are defined by the scope of the appended claims.

Claims

1. A mobile control power supply for a power plant or intelligent substation, characterized by: the device comprises an alternating current input binding post, an alternating current switch, a monitoring module, a power module, an insulation monitoring device, an alarm, a direct current switch, a direct current voltmeter, a direct current ammeter, a current sensor, a voltage sensor and a direct current output binding post;

the first end of the alternating current switch is connected with an alternating current input binding post and is used for being connected with a 220V alternating current input power supply; the power module adopts ER22005/S model, the input end of the power module and the input voltage acquisition end of the monitoring module are both connected to the second end of the alternating current switch, and the control receiving end of the power module is connected with the driving control end of the monitoring module through two switch tube control wires; the power supply module is used for outputting stable direct-current voltage under the control of the monitoring module; the input end of the voltage sensor is connected in parallel with the output end of the power supply module, and the output end of the voltage sensor is connected with the output voltage acquisition end of the monitoring module; the current sensor and the direct current ammeter are sequentially connected in series on a guide wire between the output end of the power supply module and the direct current switch, the output end of the current sensor TA is connected with the output current acquisition end of the monitoring module, and the other end of the direct current switch is connected with the direct current output binding post; the input end of the insulation monitoring device and the direct current voltmeter are both connected in parallel with the output end of the power supply module, the alarm is connected between one output end of the insulation monitoring device and the 220V alternating current working power supply, and the other output end of the insulation monitoring device is directly connected with the 220V alternating current working power supply; the alarm is used for sending out alarm light and sound signals when the direct current output loop of the control power supply is poorly grounded or the insulation is reduced; the voltage sensor and the current sensor are Hall sensors;

the input voltage sampling circuit or the output voltage sampling circuit comprises two voltage dividing resistors R30 and R31, an input resistor R32, two operational amplifiers U2A and U5A, a resistor R33, a linear optocoupler U4, a polar capacitor C20, capacitors C32 and C33, a feedback resistor R34 and a light emitting diode D3; one end of the divider resistor R30 is used as an input end of the voltage sampling circuit and is connected with an output end of the voltage sensor; the 2 pin and the 4 pin of the linear optocoupler U4 are connected with the positive electrode and the negative electrode of a 15V direct current power supply of the auxiliary power supply; the +3.3V direct current power supply at one end of the light emitting diode D3 is connected with the +3.3V direct current power supply provided by the auxiliary power supply; the output end of the operational amplifier U5A is an output end ADC1 of the voltage sampling circuit and is connected with an ADC terminal of the microprocessor; the power ends of the two operational amplifiers U2A and U5A are connected with a 15V direct current power supply provided by an auxiliary power supply;

The output current sampling circuit comprises resistors R21, R22, R23, R24, a capacitor C21, a polarity capacitor C22 and an operational amplifier U11A; one end of the resistor R21 is used as an input end of the output current sampling circuit and is connected with an output end of the current sensor; one end of the resistor R24 is connected with the output end of the operational amplifier U11A, and the other end of the resistor R is used as an output end ADC2 of the output current sampling circuit and is connected with an ADC terminal of the microprocessor; the power end of the operational amplifier U11A is connected with a 15V direct current power supply provided by an auxiliary power supply;

the insulation monitoring device is used for automatically detecting the voltage of the positive electrode and the negative electrode of the direct current output loop to the ground and judging whether the direct current loop is grounded or insulated well; the insulation monitoring device comprises two direct current input terminals 1 and 2, two change-over switches SB, resistors R1, R2, R3, R4, R5 and R6, a voltmeter V, a rectifier bridge U, an optocoupler isolation device IC1, an operational amplifier IC2, a micro relay ZJ and a triode VT; the direct current input terminals 1 and 2 are respectively connected with the output terminals VOUT+ and VOUT-of the power supply module; one end of each of the two change-over switches SB is respectively connected with the direct current input terminals 1 and 2, and the other end of each of the two change-over switches SB is connected with the voltmeter V and then grounded; the resistors R1 and R2 are connected in series and then connected in parallel between the direct current input terminals 1 and 2; the two direct current ends of the rectifier bridge U are respectively connected with the middle nodes of the resistors R1 and R2 and the ground, the two alternating current ends are connected with the two input ends of the optocoupler isolation device IC1, and the two output ends of the optocoupler isolation device IC1 are respectively connected with the direct current power supply VCC and the non-inverting input end of the operational amplifier IC 2; the non-inverting input end of the operational amplifier IC2 is simultaneously connected with the resistor R4 and then grounded, the inverting input end of the operational amplifier IC2 is connected with the resistor R3 and then connected with the direct current power supply VCC, and the inverting input end of the operational amplifier IC2 is simultaneously connected with the resistor R5 and then grounded; the output end of the operational amplifier IC2 is connected with one end of a resistor R6, the other end of the resistor R6 is connected with the base electrode of a triode VT, the collector electrode of the triode VT is connected with a coil of a micro relay ZJ and then is connected with a direct current power supply VCC, and a movable contact terminal 3 and a movable contact terminal 4 of the micro relay ZJ are used as the output end of the insulation monitoring device.

2. A portable control power supply for a power plant or intelligent substation according to claim 1, characterized in that: the movable control power supply for the power plant or the intelligent substation further comprises a surge suppressor; the surge suppressor is used for preventing the AC220V alternating current input end of the control power supply from generating surge overvoltage due to lightning strike, the surge suppressor is connected to the second end of the alternating current switch through the auxiliary alternating current switch, and the grounding end of the surge suppressor is grounded.

3. A portable control power supply for a power plant or intelligent substation according to claim 2, characterized in that: the movable control power supply for the power plant or the intelligent substation further comprises a power supply case, wherein the power supply case is used for bearing and installing other components of the control power supply, and comprises a case body (101), a front end cover (102), a case lock (103), a mounting panel (104), a rear end cover plate (105) and a handle (106); the shell of the box body (101) is grounded, and the box lock (103) is arranged at the joint of the front end cover (102) and the box body (101); the installation panel (104) is arranged at the rear side of the front end cover (102), an alternating current input binding post, an alternating current switch, a monitoring module, a power module, an insulation monitoring device, an alarm, a direct current switch, a direct current voltmeter, a direct current ammeter, a surge suppressor, a direct current output binding post and a grounding terminal are embedded and installed on the installation panel (104), and the grounding terminal is used for being connected with a grounding end of the surge suppressor; the rear end cover plate (105) and the box body (101) are of an integrated structure, and 2 fans (107) are fixedly arranged on the rear end cover plate (105) in an embedded mode; the handle (106) is arranged on one side surface of the box body (101).

4. A portable control power supply for a power plant or intelligent substation according to claim 3, characterized in that: the peripheral circuit of the monitoring module further comprises a fan driving circuit, the output end of the fan driving circuit is used as a temperature control end and is connected with 2 fans (107) on the power supply case, and the input end of the fan driving circuit is connected with the PWM square wave output end of the microprocessor and used for driving and controlling the fans to perform heat dissipation and temperature adjustment on power devices in the control power supply.

5. A portable control power supply for a power plant or intelligent substation according to claim 3 or 4, characterized in that: the power module is mounted on the mounting panel (104) through a power module bracket, the power module bracket comprises two supports, a supporting panel (1010) and a limiting structure, the two supports are two symmetrical U-shaped bases (109) with opposite openings, and 2 bracket base bolts (1011) are respectively arranged at the lower ends of the two U-shaped bases (109) and are used for being fixed with the mounting panel (104) of the power chassis; the support panel (1010) is fixedly arranged at the upper ends of the two U-shaped bases (109), and the limiting structure is two angle irons (1012) which are parallel and fixedly arranged on the support panel and used for fixing the power supply module left and right.

6. The portable control power supply for a power plant or intelligent substation of claim 5, wherein: the materials of the box body (101) and the mounting panel (104) are aluminum plates with the thickness of 2.0mm, and the box body (101) is subjected to spray coating treatment; the front end cover (102) is lined with hemispherical black sponge and is lined with a sealing piece; the box lock (103) is provided with four handles which are respectively and symmetrically arranged at two sides of the butt joint part of the front end cover (102) and the box body (101).

7. A method of controlling a power plant or intelligent substation power supply using the mobile control power supply for the power plant or intelligent substation of claim 1, characterized by: the method comprises two modes of automatic control and manual adjustment;

step 1: setting a reference output voltage Uset and a preset error e;

step 4: the fuzzy self-tuning PI control mode is entered, the error value e (k) and the difference value ec (k) between the error value e (k) and the error value e (k-1) calculated in the last control adjustment are subjected to fuzzification, table lookup is performed for fuzzy reasoning, the proportional coefficient delta Kp and the integral coefficient delta Ki are determined, fuzzy calculation is performed, PI adjustment is performed on the output voltage of the control power supply immediately, and the step 2 is returned; where ec (k) =e (k) -e (k-1), when k=1, ec (k) =e (k);

8. The method of controlling a power plant or intelligent substation power supply according to claim 7, wherein: the preset error e is set as the rated voltage U of the output end of the power supply module _N 5% of (C).